Nanotechnology

known and unknown health risks - Nanoparticles (Acknowledgements - References)

noreply@blogger.com (Unknown) — Thu, 8 Nov 2012 08:18:00 -0800

Acknowledgements

This work was supported by NANOSAFE (Risk Assessment in Production and Use of Nanoparticles with Development of Preventive Measures and apply Codes) project funded by the eu Community below the "Competitive and property Growth" Programme, Contract G1MA-CT-2002-00020. Full report are often found at http:/ / imperia5.vdi-online.de/ imperia/ md/ content/ tz/ zuknftigetechnologien/ 11.pdf

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known and unknown health risks - Nanoparticles (1. Introduction & 2. General background)
known and unknown health risks - Nanoparticles (3. Lung & 2. 4. Intestinal tract)
known and unknown health risks - Nanoparticles (5. Skin & 6. Body distribution and systemic effects of particulates)
known and unknown health risks - Nanoparticles (7. Differences in conditions between the lung and intestinal tract & 8. Conclusions)
known and unknown health risks - Nanoparticles (Acknowledgements - References)

known and unknown health risks - Nanoparticles (7. Differences in conditions between the lung and intestinal tract & 8. Conclusions)

noreply@blogger.com (Unknown) — Thu, 8 Nov 2012 07:12:00 -0800

7. Differences in conditions between the lung and intestinal tract

Although the contact with nanomaterials within the lungs and enteric tract shows several similarities vital variations between inhalation and bodily function of nanomaterials exist from the pharmacology purpose of read. within the enteric tract a fancy mixture of compounds – like secreted enzymes, eaten food, bacterium of the gut flora, etc – is gift, which may act with the eaten nanomaterial. Non-specific interaction usually reduces the toxicity of the eaten material. it's been delineated that in vitro particles area unit less cytotoxic once treated in an exceedingly medium with high macromolecule content. within the lungs, secretion or wetting agent is gift, within which antioxidants area unit gift, however these is simply neutral once a high variety of aerobic compounds is indrawn.

The transit through the enteric tract may be a comparatively quick method, the continual decay and renewal of the epithelial tissue makes positive that nanomaterials won't stay long within the enteric tract. The presence of solid material within the lumen of the intestines won't mechanically induce associate inflammatory response. indrawn materials < ten micrometer and > five micrometer won't enter the alveolar areas of the lungs, and thus these are cleared simply in healthy persons via the muco-ciliary escalator. Particles that area unit smaller than five micrometer can deposit within the alveolar area via Brownian movement. within the alveoli, water insoluble materials will solely be removed via activity by macrophages or different cells, or via transportation through the epithelial tissue to the interstitium or circulation. These processes area unit usually amid the onset of (persistent) inflammation. The particles themselves will – counting on the physical-chemical characteristics of the fabric – stay for an extended amount within the alveoli.

In the enteric tract, the eaten materials area unit stressed from acidic (stomach) to basic conditions. The shift in hydrogen ion concentration markedly changes the solubility and also the ionic state of the fabric via dynamical the surface characteristics. within the lungs, the surroundings of the lumen is a lot of constant.

7. Differences in conditions between the lung and intestinal tract

Particles within the nano-size vary will actually enter the frame via the lungs and also the intestines; penetration via the skin is a smaller amount evident. it's attainable that some particles will penetrate deep into the corium. the probabilities of penetration rely upon the scale and surface properties of the particles and conjointly on the purpose of contact within the respiratory organ, intestines or skin. when the penetration, the distribution of the particles within the body may be a robust perform of the surface characteristics of the particles. A crucial size would possibly exist on the far side that the movement of the nanoparticles in components of the body is restricted. The pharmaco-kinetic behaviour totally different|of various} sorts of nanoparticles needs elaborated investigation and a information of health risks related to different nanoparticles (e.g. target organs, tissue or cells) ought to be created. The presence of the contaminates, like metal catalysts gift in nanotubes, and their role within the determined health impacts ought to be thought-about beside the health effect of the nanomaterials.

The magnified risk of cardiorespiratory diseases needs specific measures to be taken for each recently created nanoparticle. there's no universal "nanoparticle" to suit all the cases, every nanomaterial ought to be treated severally once health risks area unit expected. The take a look ats presently accustomed test the protection of materials ought to be applicable to spot venturous nanoparticles. verified otherwise, it'd be a challenge for business, legislators and risk assessors to construct a collection of high outturn and low value tests for nanoparticles while not reducing the potency and dependability of the chance assessment. Nanoparticles designed for drug delivery or as food parts would like special attention.

known and unknown health risks - Nanoparticles (1. Introduction & 2. General background)
known and unknown health risks - Nanoparticles (3. Lung & 2. 4. Intestinal tract)
known and unknown health risks - Nanoparticles (5. Skin & 6. Body distribution and systemic effects of particulates)
known and unknown health risks - Nanoparticles (7. Differences in conditions between the lung and intestinal tract & 8. Conclusions)
known and unknown health risks - Nanoparticles (Acknowledgements - References)

known and unknown health risks - Nanoparticles (5. Skin & 6. Body distribution and systemic effects of particulates)

noreply@blogger.com (Unknown) — Wed, 7 Nov 2012 10:21:00 -0800

5. Skin

Skin is a crucial barrier, protective against insult from the surroundings. The skin is structured in 3 layers: the stratum, the derma and therefore the body covering layer. The outer layer of the stratum, the stratum (SC), covers the whole outside of the body and solely contains dead cells, that area unit powerfully keratinized. for many chemicals the SC is that the rate-limiting barrier to transdermic absorption (penetration). The skin of most class species is, on most components of the body, lined with hair. At the sites, wherever hair follicles grow, the barrier capability of the skin differs slightly from the "normal" stratified squamous stratum. Most studies regarding penetration of materials into the skin have focussed on whether or not or not medicine penetrate through the skin victimisation completely different formulations containing chemicals and/or particulate materials as a vehicle. the most sorts of particulate materials ordinarily used are: liposomes; solid poorly soluble materials like TiO2 and chemical compound particulates and submicron emulsion particles like solid lipoid nanoparticles. The penetration of those particulate carriers has not been studied intimately.

TiO2 particles area unit usually employed in sunscreens to soak up lightweight|ultraviolet illumination|UV|actinic radiation|actinic ray} light and so to safeguard skin against sunburn or genetic injury. it's been reportable by Lademann et al in [82] that micrometer-sized particles of TiO2 get through the human stratum and even into some hair follicles – as well as their deeper components. However, the authors failed to interpret this observation as penetration into living layers of the skin, since this a part of the vesicle channel (the acroinfundibulum) is roofed with a stratum corneum barrier too [82]. a unique interpretation has been steered in an exceedingly recent review by Kreilgaard [83], United Nations agency argued that "very little titanium oxide particles (e. g. 5–20 nm) penetrate into the skin and might act with the immune system". Tinkle et al [84] incontestible that zero.5- and 1.0 micrometer particles, in conjunction with motion, penetrate the stratum of human skin and reach the stratum and, sometimes, the dermis. The authors hypothesised that the lipoid layers at intervals the cells of the stratum type a pathway by that the particles will move [85] into the skin and be phagocytized by the Langerhans cells. during this study the penetration of particles is restricted to particle diameter of one micrometer or less. all the same, alternative studies reportable penetration through the skin victimisation particles with diameters of 3–8 micrometer [86,87,82] however solely restricted penetration was found usually clustered at the follicle (see above).

Penetration of non-metallic solid materials like perishable poly(D,L-lactic-co-glycolic acid (PLGA) microparticles, one to ten micrometer with a mean diameter of four.61 ± 0.8 micrometer was studied once application on to porcine skin. the quantity of microparticles within the skin attenuate with the depth (measured from the airside towards the body covering layer). At one hundred twenty micrometer depth (where viable derma present) a comparatively high variety of particles was found, at four hundred micrometer (dermis) some micro-particles were still seen. At a depth of five hundred micrometer no microparticles were found [88]. within the skin of people, United Nations agency had AN impaired humour evacuation of the lower legs, soil microparticles, oftentimes zero.4–0.5 micrometer however as larger particles of twenty five micrometer diameter, were found within the within the derma of the foot in an exceedingly patient with endemic hypertrophy. The particles area unit seen to be within the phagosomes of macrophages or within the protoplasm of alternative cells. The failure to conduct bodily fluid to the node produces a permanent deposit of silicon dioxide within the dermal tissues (a parallel is drawn with similar deposits within the respiratory organ in pneumoconiosis). this means that soil particles penetrate through (damaged) skin, most likely in each individual, and ordinarily area unit removed via the vascular system [89,90]. Liposomes penetrate the skin in an exceedingly size dependent manner. Micro-sized, and even submicron sized, liposomes don't simply penetrate into the viable stratum, whereas liposomes with a median diameter of 272 nm will extend to the viable stratum and a few area unit found within the derma. Smaller sized liposomes of 116 and seventy one nm were found in higher concentration within the derma.

Emzaloid™ particles, a kind of submicron emulsion particle like liposomes and nonionic wetter vesicles (niosomes), with a diameter of fifty nm to one micrometer, were detected within the stratum in association with the cell membranes once application to human skin [91]. The authors steered that single molecules, that compose the particles, might penetrate the living thing areas and, at sure regions within the stratum, area unit able to accumulate and reform into small spheres. in an exceedingly ensuant experiment, it absolutely was shown that the used formulation allowed penetration of the spheres into malignant melanoma cells, even to the nucleus [92].

A recent review by Hostynek [93] expressed that the uptake of metals through the skin is advanced, due to each exogenous factors (e.g. dose, vehicle, supermolecule reactivity, valence) and endogenous factors (e.g. age of skin, anatomical web site, physiological condition control). tries to outline rules governing skin penetration to administer prognosticative quantitative structure-diffusion relationships for argentiferous parts for risk assessment functions are unsuccessful, and penetration of the skin still has to be determined severally for every metal species, either by in vitro or in vivo assays.

Only restricted literature on nanoparticles penetrating the skin is offered, however some conclusions will already be drawn. Firstly, penetration of the skin barrier is size dependent, nano-sized particles area unit a lot of probably to enter a lot of deeply into the skin than larger ones. Secondly, differing kinds of particles area unit found within the deeper layers of the skin and at the present it's not possible to predict the behaviour of a particle within the skin. and at last, materials, which may dissolve or leach from a particle (e.g. metals), or burgled smaller components (e.g. Emzaloid™ particles), will probably penetrate the skin. we have a tendency to failed to notice any direct indication that particles, that had penetrated the skin, conjointly entered the circulation. The observation that particles within the skin may be phagositized by macrophages, Langerhans cells or alternative cells may be a doable road towards skin sensitisation. Tinkle et al [84] have shown that topical application of metallic element, to C3H mice, generated beryllium-specific sensitisation. These knowledge area unit per the event of a hapten-specific, cell-mediated response.

5.1 Mechanical irritation of skin

Glass fibres and Rockwool fibres area unit cosmopolitan unreal mineral fibres due to their multiple applications, principally as insulation materials, that became necessary for replacement amphibole fibres. connected with the skin, these fibres will induce eczema through the mechanical irritation. Why these fibres area unit such robust annoyance has not been examined intimately. In occlusion annoyance patch tests in humans it absolutely was found that Rockwool fibres with a diameter of four.20 ± 1.96 micrometer were a lot of irritating than those with a mean diameter of three.20 ± 1.50 micron. the very fact that "small" fibres will cause robust skin irritation has been famous for a protracted time, e.g. itch powder. it's conjointly ordinarily accepted that some sorts of imitation fibres will simply induce non-allergic eczema. though this can be public knowledge, it's not clear what makes these fibres irritants. In seek for reports on skin irritation caused by fibres with a diameter of < one hundred nm no data might be found, indicating that a lot of analysis is required.

6. Body distribution and general effects of particulates

The body distribution of particles is powerfully obsessed on their surface characteristics. as an example, coating poly(methyl methacrylate) nanoparticles with differing kinds and concentrations of surfactants considerably changes their body distribution [116]. Coating these nanoparticles with ≥ zero.1 % poloxamine 908 reduces their liver concentration considerably (from seventy five to thirteen maximize total quantity of particles administrated) thirty min once shot. Another wetter, polysorbate eighty, was effective on top of zero.5%. a unique report [94] shows that modification of the nanoparticle surface with a ion compound, didodecyldimethylammonium bromide (DMAB), facilitates the blood vessel uptake 7–10-fold. The authors noted that the DMAB surface changed nanoparticles had a letter potential of +22.1 +/- 3.2 mV (mean +/- sem, n = 5) that is important completely different from the first nanoparticles that had a letter potential of -27.8 +/- 0.5 mV (mean +/- sem, n = 5). The mechanism for the altered biological behaviour is quite unclear, however surface modifications have potential applications for intra-arterial drug delivery.

Oral uptake (gavage) of cinnamene spheres of various sizes (50 nm to three micron) in feminine Sprague Dawley rats (for ten days at a dose of one.25 mg/kg/day) resulted in general distribution of the nanoparticles. regarding seven-membered (50 nm) and 4 wheel drive (100 nm), was found within the liver, spleen, blood and bone marrow. Particles larger than one hundred nm failed to reach the bone marrow and people larger than three hundred nm were absent from blood. No particles were detected in heart or respiratory organ tissue [75].

Irrespective of the uptake route, the body distribution of particles, is most obsessed on the surface characteristics and therefore the size of the particles. it's a crucial issue in drug-design so as to assist to deliver medication to the proper target. In unintentional uptake of nanoparticles these characteristics will powerfully influence the buildup of explicit} style of particle within the particular body web site.

6.1 Nanoparticles, occlusion and respiratory organ inflammation

Epidemiological studies have reportable a detailed association between particulate pollution and vas adverse effects like myocardial infarct [95]. The latter results from rupture of AN hardening of the arteries plaque within the arteria coronaria, followed by fast coagulum growth caused by exposure of extremely reactive subendothelial structures to current blood, therefore resulting in further or complete obstruction of the vessel. Nemmar et al [96] studied the doable effects of particles on haemostasia, specializing in coagulum formation as a relevant terminus. cinnamene particles of sixty nm diameter (surface modifications: neutral, negative or positive charged) have an instantaneous impact on haemostasia by the shot. charged amine-particles junction rectifier to a marked increase in prothrombotic tendency, ensuing from thrombocyte activation. an identical impact might be obtained once the intratracheal administration of those charged cinnamene particles, that conjointly caused respiratory organ inflammation [97]. it's necessary to point that the pulmonic instillation of larger (400 nm) positive particles caused a particular pulmonic inflammation (of similar intensity to sixty nm particles), however they failed to result in a peripheral occlusion at intervals the primary hour of exposure. This lack of impact of the larger particles on occlusion, despite their marked impact on pulmonic inflammation, suggests that pulmonic inflammation by itself was light to influence peripheral occlusion. Consequently, the impact found with the smaller, ultrafine particles is most likely due, a minimum of partially, to their general translocation from the respiratory organ into the blood.

Pollutant particles like diesel exhaust particles (DEP), might cause a marked pulmonic inflammation at intervals AN hour once their deposition within the lungs. Moreover, intratracheal instillation of DEP promotes limb blood vessel and blood vessel occlusion in an exceedingly dose-dependent manner, already beginning at a dose of five μg per gnawing animal (appr. 50 μg/kg). ensuant experiments showed that prothrombotic effects persisted at half dozen h and twenty four h once instillation (50 μg/animal) and confirmed that peripheral occlusion and pulmonic inflammation aren't continually associated [97]. Solid inhaled particles area unit a risk for those that suffer from upset. Experimental knowledge indicate that several inhaled particles will have an effect on vas parameters, via pulmonic inflammation. Nano-sized particles, once passage within the circulation, may also play an instantaneous role in e.g. thrombogenisis.

Epidemiologic studies have provided valuable data on the adverse health effects of particulate pollution within the community, indicating that nanoparticles act as a crucial environmental risk issue for viscus mortality. Particle-induced pulmonic and general inflammation, accelerated arterial sclerosis, and altered internal organ involuntary perform is also a part of the patho-physiological pathways, linking particulate pollution with vas mortality. Also, it's been shown that particles deposited within the alveoli result in activation of protein production by alveolar macrophages and animal tissue cells and to enlisting of inflammatory cells. a rise in plasma body, clotting factor and C-reactive protein has been ascertained in samples of arbitrarily selected healthy adults in association with particulate pollution [95,98,99].

6.2 Nanoparticles and cellular uptake

A number of reports on cellular uptake of micro- and nano- sized particles has been printed. Reports on particle uptake by epithelium cells [100,101], pulmonic animal tissue [102,79,103,59], enteral animal tissue [51,79] alveolar macrophages [104-107,57], alternative macrophages [89,108,76,109], nerve cells [110] and alternative cells[111] area unit on the market. this can be AN expected development for somatic cell cells (macrophages) and cells that perform as a barrier and/or transport for (large) compounds. apart from macrophages, the health effects of cellular uptake of nanoparticles haven't been studied full.

6.3 Nanoparticles and therefore the barrier

One of the promising alleys of technology is organ- or cell- specific drug delivery mediate by nanoparticles [112-114]. it's expected that transport of nanoparticles across the barrier (BBB) is feasible by either passive diffusion or by carrier-mediated endocytosis. Coating of particles with polysorbates (e.g. polysorbate-80) leads to anchoring of apolipoprotein E (apo E) or alternative blood elements. Surface changed particles appear to mimic beta-lipoprotein particles and might act with the beta-lipoprotein receptor resulting in uptake by epithelium cells. Hereafter, the drug (which was loaded within the particle) is also discharged in these cells and diffuse into the brain interior or the particles is also trans-cytosed.

Also, alternative processes like tight junction modulation or P-glycoprotein (Pgp) inhibition conjointly might occur [115]. Oberdörster et al 2002 reportable the translocation of inhaled nanoparticles via the exteroception nerves [56]. Drug delivery systems crossing the BBB area unit actually welcome, however this conjointly implicates that unintended passage through the BBB is possible; thus smart safety evaluations area unit required.

6.4. Nanoparticles and aerophilic stress

It has been shown that nanoparticles, that enter the liver, will induce aerophilic stress domestically. one (one day; twenty and one hundred mg/kg) and continual (14 days) blood vessel administration of poly-isobutyl cyanoacrylate (PIBCA, a perishable particle) or cinnamene (PS, not biodegradable) nanoparticles induced a depletion of reduced glutathione (GSH) and oxidized glutathione (GSSG) levels within the liver, further as inhibition of SOD (SOD) activity and a small increase in enzyme activity. The nanoparticles failed to distribute within the hepatocytes, implicating that the aerophilic species most likely were created by activated internal organ macrophages, once nanoparticle bodily process.

Uptake of compound nanoparticles by Kupffer cells within the liver induces modifications in hepatocyte inhibitor systems, most likely attributable to the assembly of radical chemical element species [108]. we've mentioned on top of that nano-sized particles within the respiratory organ will induce, via the pulmonic inflammatory response further as via ad lib surface connected reactions, aerophilic stress. Besides pulmonic studies, not several have studied particle-induced aerophilic stress in tissues. However, the authors [108] reportable that the depletion in glutathione wasn't decent enough to initiate vital hepatocytic injury (no lipoid peroxidation). It has to be stressed that long studies area unit required to prove the safe use of those nanoparticles as a result of chronic depletion of the anti-oxidant defence will result in severe health issues.

known and unknown health risks - Nanoparticles (1. Introduction & 2. General background)
known and unknown health risks - Nanoparticles (3. Lung & 2. 4. Intestinal tract)
known and unknown health risks - Nanoparticles (5. Skin & 6. Body distribution and systemic effects of particulates)
known and unknown health risks - Nanoparticles (7. Differences in conditions between the lung and intestinal tract & 8. Conclusions)
known and unknown health risks - Nanoparticles (Acknowledgements - References)

known and unknown health risks - Nanoparticles (3. Lung & 2. 4. Intestinal tract)

noreply@blogger.com (Unknown) — Wed, 7 Nov 2012 08:15:00 -0800

3. Lung

3.1 Inhalation and pneumonic clearing of insoluble solids

The morbific effects of indrawn solid material rely totally on achieving a sufficient respiratory organ burden [15]. The respiratory organ burden is decided by the rates of deposition and clearance. Logically, for any mud or fibre, a steady-state dose level are going to be achieved once the rates acquire balance. this is often solely true once the solid material doesn't interfere with the clearance mechanisms. In relevance the burden the chemical and physical properties of the fabric itself square measure vital in so far as they influence deposition and clearance rates. Spherical solid material will be indrawn once its mechanics diameter is a smaller amount than ten micrometer. The smaller the particulates the deeper they'll travel into the respiratory organ, particles smaller than two.5 micrometer can even reach the alveoli. Ultrafine particles (nanoparticles with associate mechanics diameter of but one hundred nm) square measure deposited chiefly within the alveolar region. Fibres square measure outlined as solid materials with a length to diameter quantitative relation of a minimum of 3:1. Their penetration into the respiratory organ depends on the mechanics properties. Fibres with alittle diameter can penetrate deeper into the lungs, whereas terribly long fibres (>>20 micron) square measure preponderantly stuck within the higher airways [16-21].

The mucociliary escalator dominates the clearance from the higher airways; clearance from the deep respiratory organ (alveoli) is preponderantly by scavenger cell bodily process. The mucociliary escalator is associate economical transport system pushing the secretion, that covers the airways, along side the treed solid materials towards the mouth. The bodily process of particles and fibres ends up in activation of macrophages and induces the discharge of chemokines, cytokines, reactive element species, and different mediators; this may end in sustained inflammation and eventually fibrotic changes. The bodily process potency will be plagued by the (physical-chemical) characteristics of the solid material (see below); furthermore, fibres too long to be phagocytized (fibres longer than the diameter of the alveolar macrophage) can solely be cleared terribly slowly.

Laboratory exposure studies have shown that if the indrawn concentrations square measure low, specified the deposition rate of the indrawn particles is a smaller amount than the mechanical alveolar macrophage-mediated clearance rate within the respiratory organ, then the retention 0.5 time is concerning seventy days (steady-state respiratory organ burden throughout continuous exposure). If the deposition rate of the indrawn particles exceeds this clearance rate, the retention 0.5 time is considerably accrued, reflective associate impaired or prolonged alveolar macrophage-mediated clearance perform with continued accumulation of respiratory organ burden (overload). indrawn fibres, that square measure persistent within the alveoli, will move with the pneumonic animal tissue cells or perhaps penetrate the alveolar wall and enter the respiratory organ tissue. These fibres square measure typically represented as being within the "interstitial" wherever they'll lie between or among the cells creating up the alveolar walls. Bio-persistent solid materials, actually those particles containing agent substances or amphibole fibres or silicon oxide, that stay for years within the lungs, increase the chance of developing cancer.

3.2 Deposition and clearing of solid nanomaterials

It has been rumored recently that nanotubes show a symbol of toxicity [22], confirmed in 2 freelance publications by Warheit et al [23] and Lam et al [24], that incontestible the pneumonic effects of single walled cabon nanotubes in vivo once intratracheal instillation, in each rats and mice. each teams rumored tumour formation, and a few opening inflammation. The analysis cluster of Warheit et al [23] terminated that these findings (multifocal granulomas) might not have physiological connectedness, and will be associated with the instillation of a bolus of collective nanotubes. except for the authors of [24] their results indicate that if carbon nanotubes reach the lungs, they're additional|far more|rather more|way more} harmful than smut and might be more harmful than quartz. These studies have to be compelled to be scan with some caution as a result of a study by the National Institute for activity Safety and Health (NIOSH) showed that none or solely alittle fraction of the nanotubes gift within the air will be indrawn [25].

Clearance from the respiratory organ depends not solely on the entire mass of particles indrawn however additionally on the particle size and, by implication, on particle surface, as shown within the following studies. A sub-chronic three months inhalation exposure of rats to ultrafine (~20 nm) and fine (~200 nm) titanium oxide (TiO2) particles incontestible that the ultrafine particles cleared considerably slower, showed additional translocation to opening sites and to regional humour nodes in comparison to the fine TiO2 particles [26]. By scrutiny smut particles of comparable size and composition however with important specific extent distinction (300 versus thirty seven m2/g), it had been found that the biological effects (inflammation, genotoxicity, and histology) were smitten by specific extent and not particle mass. Similar findings were rumored in earlier studies on tumorigenic effects of indrawn particles. it had been shown that tumor incidence correlative higher with specific extent than with particle mass [27,28].

Comparing the health effects of inveterately indrawn TiO2 particles with clearly completely different sizes, it's outstanding that the low exposure (10 mg/m3) study [29] resulted in an exceedingly larger respiratory organ tumor incidence than the high exposure (250 mg/m3) study [30]. The indrawn particles in each studies consisted of collective primary particles, with associate mechanics diameter that was in all probability not terribly completely different. the first particle size of the low dose study was twenty nm, whereas it had been some three hundred nm within the latter study.

In summary, most nano-sized spherical solid materials can simply enter the lungs and reach the alveoli. These particles will be cleared from the lungs, as long because the clearance mechanisms aren't plagued by the particles themselves or the other cause. Nano-sized particles square measure additional seemingly to hamper the clearance leading to the next burden, presumably amplifying any attainable chronic effects caused by these particles. it's additionally vital to notice that specific particle extent is maybe an improved indication for max tolerated exposure level than total mass. indrawn nano-fibres (diameter smaller than one hundred nm) can also enter the alveoli and their clearing would, additionally, rely on the length of the particular fibre. Recent publications on the pneumonic effects of carbon nanotubes ensure the intuitive concern that nano-sized fibre will induce a rather general non-specific pneumonic response.

3.3 Particle surface and biocompatibility

Reports on the surface properties of nanoparticles, each physical and chemical, stress that nanoparticles dissent from bulk materials. Their properties rely heavily on the particle size. Therefore, nanoparticles aren't simply tiny crystals however associate intermediate state of matter placed between bulk and molecular material. severally of the particle size, 2 parameters play dominant role. the fees carried by the particle connected with the cell membranes and therefore the chemical reactivity of the particle [31].

3.3.1 Surface charges

Polycationic macromolecules show a powerful interaction with cell membranes in vitro. a decent example will be found within the Acramin F textile paint system. 3 poly-cationic paint elements exhibited extended toxicity (LD50 typically below one hundred mg/ml for associate incubation of 20–24 hours) in numerous cell cultures, like primary cultures of rat and human sort II pneumocytes, and alveolar macrophages and human erythrocytes. The authors argued that the multiple positive charges play a crucial role within the harmful mechanism [32,33]. Biocompatibility studies [34] unconcealed that the toxicity of polycationic materials like DEAE-dextran and poly-L-lysine (PLL) [35,36], dendrimers [37] and polyethylenimine (PEI) [38] will increase with the rise in their relative molecular mass. However, these findings apply solely to polymers having same chemical structure, however not for various kinds of polycations. Consequently, to elucidate the toxicity of polymers with completely different structures more parameters have to be compelled to be taken into consideration.

Dekie et al [39] terminated that the presence of a primary aminoalkane cluster on poly L-glutamic acid derivatives contains a important harmful result on red blood cells inflicting them to agglutinate. Not solely the kind of amino perform however additionally the charge density ensuing from the quantity and special arrangement of the cationic residues is a crucial issue for toxicity. Ryser [40] prompt that a three-point attachment is critical for eliciting a biological response on cell membranes, and argued that the activity of a compound can decrease once the house between reactive aminoalkane teams is accrued. The arrangement of cationic charges depends on the three-dimensional structure and adaptability of the macromolecules and determines the accessibility of their charges to the cell surface. as an example, branched molecules were found to be additional economical in neutralising the cell surface charge than polymers with linear or spherical structure, as rigid molecules have additional difficulties to connect to the membranes than versatile molecules [41]. Therefore, high cationic charge densities and extremely versatile polymers ought to cause higher cytotoxic effects than those with low cationic charge densities. spherical polycationic macromolecules (cationised Human liquid body substance Albumine (cHSA), ethylenediamine-core poly(amidoamine) dendrimers (PAMAM) were found to be polymers with a decent biocompatibility (low cytotoxicity), whereas polymers with a additional linear or branched and versatile structure (e.g. polydiallyldimethylammonium chloride (DADMAC), PLL, PEI) showed higher cell damaging effects.

3.3.2 The wetting agent interaction and surface chemistry

Geiser et al [42] studied the influence of the particle surface chemistry on its interaction with the lung's surface-lining layer. They found that, notwithstanding the character of their surfaces, particles are going to be submersed into the liner layer once their deposition in tiny airways and alveoli. This displacement is promoted by the wetting agent film itself, whose physical phenomenon falls quickly to comparatively low values [42,43]. On the opposite hand, reactive teams on a particle surface will definitely modify the biological effects. For silica, it's been shown that surface modification of quartz affects its toxicity, inflammogenicity and fibrogenicity. These variations square measure chiefly attributable to particle surface characteristics [44]. Specific toxicity of silicon oxide is powerfully correlative with the looks of surface radicals and reactive element species (ROS), that is taken into account to be the key event within the development of pathology and carcinoma by this compound [45].

Although the kind of particle doesn't appear to play a crucial role in whether or not it's embedded within the wetting agent lining of the alveoli, the embedding method itself is crucial. Particle-cell interaction is feasible solely once the immersion of the particulates within the lining fluid and analysis is required to review this development well in reference to indrawn nanoparticles. Logically, as represented within the report for silicon oxide [45], the reactive teams on nanoparticles influence their interaction with the respiratory organ (or additional general with biological material). In some instances it'd be attainable to predict the reactivity of the nano-surface. However, considering the scarceness of knowledge, it'd be smart to verify these predictions by some laboratory testing.

3.4 general translocation of indrawn particles

The impact of indrawn particles on different organs has solely recently been recognised. Most analysis has targeting the attainable consequences of particle connected malfunction of the cardio-vascular system, like cardiopathy, curdling [46] etc. However, recent information support the construct that the involuntary system may be a target for the adverse effects of indrawn particulates [47,48,11]. 2 complementary hypotheses make a case for the vas malfunctions once inhalation of ultra-fine particles. the primary hypothesis explains the discovered effects by the prevalence of sturdy (and persistent) pneumonic inflammatory reactions within the lungs, resulting in the discharge of mediators (see above), which can influence the guts, curdling, or different vas endpoints. The second hypothesis is that the particles translocate from the lungs into the circulation and therefore, directly or indirectly, influence stoppage or vas integrity.

In the analysis of the health effects of indrawn nanoparticles the translocation to the circulation is a crucial issue. Conhaim and colleagues [49] found that the respiratory organ animal tissue barrier was best fitted by a three-pore-sized model, together with alittle range (2%) of large-sized pores (400-nm pore radius), associate intermediate range (30%) of medium-sized pores (40-nm pore radius), and a really sizable amount (68%) of small-sized pores (1.3-nm pore radius). the precise anatomical location of this structure, however, remains to be established (see the review by Hermans and Claude Bernard [50]). till recently, the attainable passage of xenobiotic particles has not been attracting abundant attention, although, the construct is currently gaining acceptance in pharmacological medicine for the administration of molecule medicine by inhalation [51]. Nemmar et al [11] studied the particle-translocation of indrawn ultrafine metallic element (99mTc) tagged carbon particles to the blood. These particles, that square measure terribly kind of like the ultrafine fraction of actual waste particles, subtle quickly – among five minutes – into the circulation (Fig 4). The authors terminated that bodily process by macrophages and/or endocytosis by animal tissue and epithelial tissue cells square measure liable for particle-translocation to the blood however different roots should additionally exist.

Translocation of indrawn ultrafine particles. Time-activity curve over liver and bladder expressed as p.c of initial respiratory organ radiation. Insert, Whole body gamma camera image of one representative volunteer recorded at hour. The radiation over the organs is expressed as counts per minute (CPM) per element at intervals every region of interest (ROI). The values recorded over the abdomen weren't enclosed as a result of this radiation might also come back part from swallowing of particles deposited within the mouth. Reproduced with permission from Nemmar et al, "Passage of indrawn particles into the blood circulation in humans", Circulation 2002;105(4):411-41.

The literature on the translocation of terribly tiny particles from the lungs into the blood circulation is restricted and infrequently conflicting. A recent study has rumored deposition Associate in Nursingd clearance over two h of an ultrafine (60 nm) 99mTc labeled aerosol in human volunteers. No vital emission was found within the liver (1–2 capitalize on the inhaled radioactivity) however, sadly, no emission measurements with blood were rumored [52]. In agreement with findings of Nemmar et al [11], Kawakami et al. [53] have rumored the presence of emission in blood like a shot when inhalation of 99mTc-technegas in human volunteers. it's additionally illustrious [54] that aerosolized internal secretion provides a speedy therapeutic impact though the pathways for this translocation area unit still unclear. additionally to human studies, in experimental animal studies, we have a tendency to [11] et al [55,16,57] have rumored extra-pulmonary translocation of ultrafine particles when intra-tracheal instillation or inhalation. However, the number of ultrafine particles that translocate into blood and extra-pulmonary organs differed among these studies. it's additionally been shown that, following intranasal delivery, styrene microparticles (1.1 micron) will translocate to tissues within the general compartment [58]. A recent study [59] has provided, for the primary time, morphological information showing that inhaled styrene particles area unit transported into the pneumonic capillary house, presumptively by trans-cytosis. Another alley of translocation from the lungs towards alternative organs has been undertaken by Oberdörster et al [19]. In inhalation experiments with rats, exploitation 13C-labelled particles, they found that nano-sized particles (25 nm) were gift in many organs twenty four hours when exposure. the foremost extraordinary finding was the invention of particles within the central system (CNS). The authors examined this development any and located that particles, when being obsessed by the nerve cells, may be transported via nerves (in this experiment via the sense modality nerves) at a speed of two.5 millimetre per hour [56].

Passage of solid material from the pneumonic animal tissue to the circulation appears to be restricted to nanoparticles. the difficulty of particle translocation still have to be compelled to be clarified: each the trans-epithelial transport within the alveoli and therefore the transport via nerve cells. Thus, the role of things governing particle translocation like the approach of exposure, dose, size, surface chemistry and time course ought to be investigated. for example, it might be additionally vital to understand however and to what extent respiratory organ inflammation modulates the extra-pulmonary translocation of particles.

3.5 Fibre bio-persistence

Long non-phagocytizable fibres (in humans longer than twenty micron) won't be effectively cleared from the tract. the most determinants of fibre bio-persistence area unit species specific physiological clearance and fibre specific bio-durability (physical-chemical processes). within the alveoli the speed at that fibres area unit physically cleared depends on the flexibility of alveolar macrophages to phagocytose them. Macrophages containing fibres longer than their own diameter might not be mobile and be unable to clear the fibres from the respiratory organ. The bio-durability of a fibre depends on dissolution and leach furthermore as mechanical breaking and ripping. Long fibres within the respiratory organ will disintegrate, resulting in shorter fibres which will be removed by the macrophages. Bio-persistent styles of amphibole, wherever breakage happens lengthwise, end in additional fibres of an equivalent length however smaller diameter. Amorphous fibres break perpendicular to their long axis [60,61], leading to fibres which will be engulfed by the macrophages.

It is axiomatic that the slower the fibres area unit cleared (high bio-persistence), the upper is that the tissue burden and therefore the longer the fibres reside {in a|during a|in Associate in Nursing exceedingly|in a very} tissue the upper is that the chance of an adverse response. A milestone was set by women's rightist et al [62,63] WHO undertook a series of experiments with seventeen samples of fastidiously sized fibrous glass. They found that for carcinoma induction in rats, the height activity was within the fibres larger than eight metric linear unit long and fewer than one.3 metric linear unit in diameter. These findings area unit referred to as the "Stanton hypothesis". but these results don't strictly indicate that each one fibres longer than the lower threshold area unit equally active or that shorter fibres aren't, though fibres but five metric linear unit long failed to seem to contribute to carcinoma risk in exposed rats [64]. Risk seems to extend with length, with fibres over forty metric linear unit long imposing the best risk. For the recent review see Schins [65].

The bio-durability of fibres with a diameter < a hundred nm can in all probability not disagree from larger inhalable fibres. Therefore, nice caution should be taken just in case of the contact with nano-fibres, Bio-durability tests should be performed before emotional any product containing them. Carbon nanotubes, that area unit of high technical interest, area unit one in all the materials which require to be tested exhaustive regarding bio-persistence and cancer risk. the primary toxicologic studies indicated that carbon nanotubes may be a risk for human health [22-24], whereas exposure assessment did indicate that these materials area unit in all probability not inhaled [25].

4. viscus tract

Already in 1926 it had been recognised by Kumagai [66] that particles might translocate from the lumen of the viscus tract via aggregations of viscus lymphoid tissue (Peyer's patches (PP)), containing M-cells (specialised somatic cell enterocytes). Particulate uptake happens not solely via the M-cells within the PP and therefore the isolated follicles of the gut-associated animal tissue, however additionally via the conventional viscus enterocytes. There are variety of fantastic reviews on the topic of viscus uptake of particles [51,66]. Uptake of inert particles has been shown to occur trans-cellularly through traditional enterocytes and PP via M-cells, and to a lesser extent across para-cellular pathways [67]. ab initio it had been assumed that the PP failed to discriminate powerfully within the kind and size of the absorb particles. Later it's been shown that changed characteristics, like particle size [68] the surface charge of particles [69], attachment of ligands [70,71] or coating with surfactants [72], offers potentialities of site-specific targeting to completely different regions of the gastro viscus tract (GIT), together with the PP [73].

The dynamics of particle translocation within the viscus depends on diffusion and accessibility through mucous secretion, initial contact with enterocyte or M-cell, cellular trafficking, and post-translocation events. Charged particles, like carboxylated styrene nanoparticles [69] or those composed of charged polymers exhibit poor oral bioavailability through static repulsion and mucous secretion defence. Szentkuti [74] determined the speed of particle diffusion across the mucous secretion layer to the enterocyte surface with regard to each size and surface charge of the particles. In brief, Szentkuti [74] ascertained that ion nanometer-sized latex particles became entrapped within the charged mucous secretion, whereas repulsive carboxylated fluorescent latex nanoparticles were able to diffuse across this layer. The smaller the particle diameter the quicker they may permutate the mucous secretion to succeed in the colonic enterocytes; fourteen nm diameter penetrate inside two min, 415 nm particles took thirty min, whereas 1000-nm particles were unable to translocate this barrier. Within, the time of the experiment (30 min) none of the particles was endocytosed by the enterocytes despite the actual fact that the latex nanoparticles preferentially certain the cell surface additional powerfully than the mucous secretion. when a extended time window (oral alimentation for many days) a distributed accumulation of charged particulates within the plate propria (connective tissue below the epithelia) was found compared to drained latex nanoparticles within the same size vary [69].

Particulates, once within the sub-mucosal tissue, area unit able to enter each humor and capillaries. Particles getting into the humor area unit in all probability vital within the induction of humor immune responses whereas those that enter the capillaries become general and might reach completely different organs. In one study [75], the body distribution when translocation of styrene particles was examined in some detail. styrene spheres (ranging from fifty nm to three micron) were fed by alimentation to feminine Sprague Dawley rats daily for ten days at a dose of one.25 mg/kg. the maximum amount as thirty four attempt to twenty sixth of the fifty and a hundred nm particles were absorbed severally. Those larger than three hundred nm were absent from blood. No particles were detected in heart or respiratory organ tissue.

4.1 viscus Translocation and unwellness

Crohn's disease is characterized by transmural inflammation of the epithelial duct. it's of unknown aetiology, however it's steered that a mixture of genetic predisposition and environmental factors play a task. Particles (0.1–1.0 micron) area unit related to the unwellness and indicated as potent adjuvants in model antigen-mediated immune responses. in a very double-blind irregular study, it's been shown that a particle low diet (low in metal and exogenous microparticles) alleviates the symptoms of inflammatory bowel disease [76]. though there's a transparent association between particle exposure and uptake and inflammatory bowel disease, very little is understood of the precise role of the phagocytosing cells within the viscus animal tissue. it's been steered that the disruption of the animal tissue barrier operate by cell death of enterocytes may be a potential trigger mechanism for membrane inflammation. The patho-physiological role of M cells is unclear; e.g., it's been found that in inflammatory bowel disease M cells area unit lost from the animal tissue. alternative studies found that material uptake (endocytose) capability of M cells is iatrogenic below varied immunologic conditions, e.g. a larger uptake of particles (0.1 micron, one metric linear unit and ten metric linear unit diameter) has been incontestable within the inflamed colonic tissue layer of rats compared to non-ulcerated tissue [77,78] and inflamed passageway [79].

Diseases apart from of gut origin even have marked effects on the flexibility of rotter to translocate particles. The absorption of 2-micron styrene particles from the PP of rats with by experimentation iatrogenic polygenic disease is accrued up to 100-fold (10% of the administered dose) compared to traditional rats [80]. However, the diabetic rat displayed a half-hour decrease within the general distribution of the particles. One potential clarification for this discrepancy is that the accrued density of the basal plate underlying the GI tissue layer of diabetic rats which will impede particle translocation into deeper villous regions. This uncoupling between increased viscus absorption and reduced general dissemination has additionally been ascertained in Dexamethasone Intensol treated rats [81].

From the literature cited higher than it's clear that built nanoparticles may be obsessed via the viscus tract. normally the viscus uptake of particles is best understood and studied in additional detail than pneumonic and skin uptake. owing to this advantage it's perhaps potential to predict the behaviour of some particles within the intestines however precaution ought to be taken. For those nanoparticles designed to stabilise food or to deliver drug via viscus uptake alternative, additional hard, rules exist and will be followed before promoting these compounds.

known and unknown health risks - Nanoparticles (1. Introduction & 2. General background)
known and unknown health risks - Nanoparticles (3. Lung & 2. 4. Intestinal tract)
known and unknown health risks - Nanoparticles (5. Skin & 6. Body distribution and systemic effects of particulates)
known and unknown health risks - Nanoparticles (7. Differences in conditions between the lung and intestinal tract & 8. Conclusions)

known and unknown health risks - Nanoparticles (1. Introduction & 2. General background)

noreply@blogger.com (Unknown) — Wed, 7 Nov 2012 00:35:00 -0800

Abstract

Manmade nanoparticles vary from the well-established multi-ton production of smut and treated silicon oxide for applications in plastic fillers and automobile tyres to mcg quantities of fluorescent quantum dots used as markers in biological imaging. As nano-sciences square measure experiencing large investment worldwide, there\'ll be an extra rise in shopper merchandise counting on technology. whereas advantages of technology square measure wide heralded, the discussion of the potential effects of their widespread use within the shopper and industrial merchandise square measure simply setting out to emerge. This review provides comprehensive analysis of information offered on health effects of nanomaterials.

1. Introduction

Scientists world-wide square measure continued to find distinctive properties of everyday materials at the sub micrometer scale [1,2]. This size domain is best called nano- (a billionth) meter area. This novel material properties common discernible solely at the nano-scale dimensions have already found their 1st business applications [3]. for instance, nanomaterials square measure gift in some sunblockers toothpaste, paint and health tools and even food merchandise. Manmade nanoparticles ranges from the well-established multi-ton production of smut and treated silicon oxide for applications in plastic fillers and automobile tyres to mcg quantities of fluorescent quantum dots used as markers in biological imaging. As nano-sciences square measure experiencing large investment worldwide [4,5], there\'ll be an extra rise in shopper merchandise counting on technology [6].

Did you know about the wunderkind nanotechnology in pharmaceutics: Creating multifunctional nanocarriers

While advantages of technology square measure wide heralded, the discussion of the potential effects of their widespread use within the shopper and industrial merchandise square measure simply setting out to emerge [7,8]. each pioneers of technology [9] and its opponents [10] square measure finding it extraordinarily onerous to argue their case as there\'s restricted info offered to support one facet or the opposite. it\'s been shown that nanomaterials will enter the shape through many ports. Accidental or involuntary contact throughout production or use is possibly to happen via the lungs from wherever a speedy translocation through the blood stream is feasible to alternative important organs [11]. On the cellular level a capability to act as a factor vector has been incontestable for nanoparticles [12]. smut nanoparticles are concerned in meddlesome with cell signalling [13]. there\'s work that demonstrates uses of DNA for the dimensions separation of carbon nanotubes [14]. The DNA strand simply wraps around it if the tube diameter is true. whereas wonderful for the separation functions it raises some issues over the results of carbon nanotubes coming into the shape.

In this review we have a tendency to summarise the noted facts regarding nanomaterial hazards, discuss the potential entry points of nanoparticles into the shape, explore their probably pathways within the body and analyse printed experimental results on the bioactivity of nanomaterials.

2. General background

Human skin, enteral tract and lungs square measure continually in direct contact with the atmosphere. Whereas skin acts as a barrier, lungs and enteral tract additionally enable transport (passive and/or active) of assorted substances like water, nutrients or chemical element. owing to that truth they\'re probably to be a primary port of entry for nanomaterials journey into the shape. Our data during this field primarily comes from drug delivery (pharmaceutical research) and pharmacological medicine (xenobiotics) studies. The functions of the human skin as a strict barrier and no essential parts square measure obsessed through the skin (except radiation necessary to make up alimentation D). The lungs exchange chemical element and carbonic acid gas with the atmosphere, and a few water escapes with heat exhaled air. The enteral tract is in shut contact with all the materials obsessed orally; there all nutrients (except gasses) square measure changed between the body and also the atmosphere.

The microscopic anatomy of the environmental contact sides of those 3 organs is considerably totally different. The skin of associate degree adult human is roughly one.5 M2 in space, and is at the most places coated with a comparatively thick 1st barrier (10 micron) that is build of powerfully keratinised dead cells (Fig 1). This 1st barrier is troublesome to pass for ionic compounds additionally as water soluble molecules.

Figure 1. schematic illustration of human skin; corneum is that the prime of the 5 layers creating cuticle, it's composed of keratinised dead cells affixed by lipids. it's shed off and replaced each period of time. looking on the a part of the body its thickness varies from zero.05 mm to 1.5 mm.

The respiratory organ consists of 2 completely different elements, airways (transporting the air in and out the lungs) and alveoli (gas exchange areas). Human lungs contain regarding 2300 kilometre of airways and three hundred million alveoli (gas exchange areas) (Fig 2). The extent of the lungs is a hundred and forty M2 in adults, as massive as a court. The airways square measure a comparatively strong barrier, an energetic epithelial tissue protected with a viscous layer of mucous secretion. within the gas exchange space, the barrier between the alveolar wall and therefore the capillaries is extremely skinny. The air within the lumen of the alveoli is simply 0.5 micrometer away from the blood flow. the massive extent of the alveoli and therefore the intense air-blood contact during this region makes the alveoli less well protected against environmental injury compared with airways.

Figure 2. cross-sectional of alveoli; Schematic cross-sectional of alveoli showing a really skins (500 nm) separation between blood and air. associate degree SEM image of the alveoli is shown within the inset.

known and unknown health risks - Nanoparticles (1. Introduction & 2. General background)
known and unknown health risks - Nanoparticles (3. Lung & 2. 4. Intestinal tract)
known and unknown health risks - Nanoparticles (5. Skin & 6. Body distribution and systemic effects of particulates)
known and unknown health risks - Nanoparticles (7. Differences in conditions between the lung and intestinal tract & 8. Conclusions)

nanotechnology Soldiers - how worried should we be?

noreply@blogger.com (Unknown) — Tue, 21 Jun 2011 21:06:00 -0700

All leading powers are making efforts to investigate and acquire nanotechnology- based materials and systems for militaristic use. Denizen and European countries, with the exception of Sverige (Norse Justification Nanotechnology System), do not run devoted programs for defence nanotechnology explore. Rather, they combine various nanotechnology-related projects within their traditional defense-research structures, e.g., as materials research, electronic devices explore, or bio-chemical extortion research. Not so the U.S. soldierly. Stressing continuing study superiority as its principal strategic asset, it is dictated to use nanotechnology for time militaristic use and it sure wants to be No. 1 in this expanse. The U.S. Department of Protection (DoD) is a statesman investor, outlay fountainhead over 30% of all yankee finance dollars in nanotechnology. Of the $352m spent on nanotech by the DoD in 2005, $1m, or roughly 0.25%, went into investigate treatment with potentiality welfare

Annual DoD investment in nanotechnology; 2006 estimated. (Source data: DoD "Defense Nanotechnology Research and Development Programs", May 8, 2006)

Proposed and actively pursued personnel nanotech programs screening a wide grasp of applications to improve the execution of existing systems and materials and estimate new ones. The primary areas of investigate mass with explosives (their chemical placement as fit as their containment); bio and penalisation (for both hurt direction and show improvement); biological and chemical sensors; electronics for computing and assemblage; superpower multiplication and hardware; structural materials for attain, air and naval vehicles; coatings; filters; and fabrics.

Structure of the DoD Nanotechnology Program

In the mid-1990s the DoD identified nanotechnology as one of six "Strategic Explore Areas" (the else fivesome beingness ergonomics sciences, humanlike show sciences, accumulation ascendency, multifunction materials, feat and driving sciences). The DoD nanotechnology schedule is grouped into figure curriculum portion areas (PCAs), which mirror the PCAs of the U.S. Nationalistic Nanotechnology Start (NNI):

PCA 1: fundamental nanoscale phenomena and processes
PCA 2: nanomaterials
PCA 3: nanoscale devices and systems
PCA 4: instrumentation research, metrology, and standards for nanotechnology
PCA 5: nanomanufacturing
PCA 6: major research facilities and instrumentation acquisition
PCA 7: societal dimensions

Active half of the DoD's nanotech promotion goes to Authority (Squad Progressive Research Projects Office), with the pose roughly evenly division between Service, Blue and Air Penetrate. Likewise Agency, the bailiwick agencies guiding the effort are the Naval Explore Workplace (NRL), the Service Search Work (ARL), the Air Organization Duty of Scientific Search (AFOSR), and MIT's Make for Shirker Nanotechnologies (ISN). In addition, the DoD secure a Answer Lincoln Search Maiden on NanoTechnology (DURINT). The DURINT papers is planned to raise U.S. universities' capabilities to fulfil basal study and field search and associated education

Most of the DoD dollars spent to date have gone into basic research
and engineering. Insofar as these engineering and materials aspects of
military nanotechnology incorporate engineered nanomaterials, there are
near-term issues that need to be discussed and resolved: the potential
toxicity of such materials (which applies to all engineered
nanomaterials, not just those for military use), their impact on humans
and the environment, and if and how release of such nanomaterials into
the environment through military use could exceed release from
non-military uses.

While very active in developing nanotech applications, the military
is much more passive in assessing the risks and is content to monitor
what other agencies do. An
Army document (pdf download 496 KB) states that “A key component of
the leadership role in nanotechnology is protecting the work force,
civilian and military, from the unintended consequences of
nanotechnology processes and materials. The Army should take an active
role in drafting environmental, safety, and occupational health
guidelines for nanomaterials to ensure contractors follow best
environmental practices in the development, manufacture, and application
of the new technology.” However, this “active role” appears not yet to
have materialized.

On the right: Future Warrior, a
visionary concept of how the Soldier of 2025 might be equipped.It is an
integrated technology system that provides ballistic protection,
communications/ information, chem/bio protection, power, climate
control, strength augmentation, and physiological monitoring.
Incorporating nanotechnology applications currently under development by
the Army and MIT, the Soldier ensemble relies on a three-layer bodysuit
combined with a complete headgear system.(Source: MIT's Institute for
Soldier Nanotechnologies)

A spokesman for the U.S. Army Research Office told Nanowerk:
“Regarding DoD and the health and safety concerns surrounding
nanotechnology, DoD is committed to assuring the health and safety of
war fighters utilizing future nanotechnology-based applications. The
primary strategy for this is to actively monitor this area in order to
leverage the investments and expertise of major health agencies
worldwide to identify potential health risks and implement optimal and
appropriate safety practices for both war fighters and defense product
developers. By partnering with and relying upon agencies such as NIH
(National Institutes of Health), EPA, and NIOSH (National Institute for
Occupational Safety and Health), who are the true experts with such
matters, we believe we will be able to rapidly and accurately address
these concerns while simultaneously avoiding duplicative efforts.”

Military Nanotech Risk Factors Go Beyond Civilian Risk

Few of the military-motivated research could clearly mortal a positive combat on familiar life (e.g., author powerful batteries, bio and chemical sensors to discover pollutants, filters to withdraw nanoscale pollutants and toxins, intelligent fabrics). Others not exclusive posture the similar voltage danger that commercially victimized engineered nanomaterials do, for example during creation, but, due to their witting area of use, could person a greater adventure of reaching and affecting the surround. Two examples:

Noncombatant activities ofttimes outcome in lug beingness dyspneic up. Blasts by high-tech weaponry could activity hepatotoxic nanoparticles (which already is the soul with deficient metal armament) as compartment as plumping quantities of nanoengineered particles contained in both ordnance and protective weapons systems and armors (e.g., coatings could vent particles into the environs, especially during weapons change).
Large-scale use of nanotech sensors could individual an touch on the surroundings when these sensors signal to demean and engineered nanoparticles wetting into the begrime.

Of substantial anxiety is the converse to what magnitude military nanotech could further to destabilization (when one warlike cause develops a subject that others cannot effectively protect against) and hollow arms-control agreements equivalent the Begotten Weapons Orthodoxy. A NATO meditate aggroup states that "the potential for nanotech-driven innovations in chemical and life weapons are peculiarly disquieting as they can substantially enhance the conveying mechanisms of agents or noxious substances. The cognition of nanoparticles to penetrate the frail embody and its cells could kind natural and chemical battle much writer workable, easier to handle and to through against particularised, longer-term essay factors resist from hotly debated concepts treatment with molecular facility and self-replicating nanomachinery or from societal issues much as the voltage destabilization expose by military nanotechnology applications (e.g., What gift be the fight of present sensor nets and free disorderly systems? What are the honorable implications of non-medical implants in soldiers?).

Some examples

Here are modern and near-term (from today until 2010) projects that module compound "free" engineered nanoparticles, i.e., where at any traveling in production or use independent nanoparticles of a pith are immediate (compiled from world collection on varied DoD websites):

Field-responsive particles impregnated in microchannels, fibers, and froth packages to be utilised as load-transfer devices to remove/relieve skeletal loads (e.g., for built-in splints) (ISN - Create for Shirker Nanotechnologies)
Wasted films made of paper nanotubes that can be deposited onto surfaces for electrically lively coatings (Naval Research Work - NRL)
Quantum dots for sensors (NRL)
Late coatings containing polymer nanocomposites (DARPA - Team Modern Explore Projects Implementation and AHPCRC - Gray Shrilling Action Engineering Investigate Property)
Nanocomposites and engineered nanoparticles for high-energy armament (ICB - Make for Collaborative Biotechnologies)
Bio-molecular motors (Office)
Polymeric and nanostructured materials for life and chemical sensors (NRL)
Nanometallics for armaments (Gray Research Work - ARL)
Energy-absorbing nanomaterials (ISN)
Nanostructured magnetized materials for controlled adhesives (Agency and Office) and as transduction mechanism for monitoring and controlling life process at the pitted and, finally, single-molecule rank (DARPA)
Consciousness Decontaminating Surfaces exploiting opencut structures of nanomaterials (DARPA)
Nanowires and copy nanotubes for nanoelectronics (NRL)
Neural-electronic interfaces for visual, auditory and locomote prostheses implanted into the embody (Authority, NRL)
Gilded nanocluster-based sensors and electronics (NRL)
Incorporating carbon nanotubes into perpetual high-strength and high-stiffness structural element fabric (DARPA)
Energy-absorbing and mechanically lively nanomaterials in vesture and embody outfit that instrument be object of the time confederate's battlesuit (ISN)

This recite is far from thoroughgoing. Solon seer applications and materials such as performance- enhancing nanoengineered protheses and bio-engineered weapons are conceptually executable but are unlikely to see realisation within the next 10-15 life.

Nanotechnology saves Resurgence masterpieces, Indian wallpaintings, and old shipwrecks

noreply@blogger.com (Unknown) — Tue, 21 Jun 2011 20:36:00 -0700

Nanotechnology has latterly institute applied applications in the advance and age of the world's cultural acquisition. Nanoparticles of calcium and magnesium compound and carbonate eff been misused to rejuvenate and protect fence paints, much as Maya paintings in Mexico or 15th century Italian masterpieces. Nanoparticle applications were also victimized to repay old paper documents, where acid inks hump caused the cellulose fibers to outstrip up, and to address acidulent flora from a 400-year-old wreck.

Aside from the enormously abundant ethnic resources in the metropolis of Town, it is one of the most eligible places for improvement studies. For representative, after the 1966 Florence mickle, the Heart for Colloid and Shallow Field (CSGI) research set at the University of Town, supported by Academician. Enzo Ferroni and currently directed by Piero Baglioni, was the initial scholarly establishment that practical a exact scientific way to the work of cultural attribute abjection.

CSGI has industrial the most front nanotechnology-based methods for the restoration of surround paintings. These include methods for cleaning and separation of resins from support and oil paintings, for frescoes integration, and for product de-acidification. Currently these methods are victimised in more parts of the world.

Applications of nanotechnology-based processes to surround paintings integration and press de-acidification soul newly provided readable evidences of the vast possible of nanotechnology for cultural attribute advance. Nanodispersions of solids, micelle solutions, gels and microemulsions tender new sure shipway to regenerate and orbit mechanism of art by convergency unitedly the main features and properties of soft-matter and hard-matter systems, allowing the reasoning of systems specifically tailored for the mechanism of art to advertise the diminution processes which threaten galore priceless masterpieces.
Nanotechnology remodeled paintings

The difference between pre- & post-restoration using nanoparticle-based methods on Italian wall paintings. (Source: Baglioni, P., R. Giorgi & C. C. Chen, "Nanoparticle expertise saves cultural relics, & potential for a multimedia digital library," DELOS/NSF Workshop on Multimedia Contents in Digital Libraries, Crete, Greece, June 2-3, 2003.)

The difference between pre- and post-restoration using nanoparticle-based methods on figure Italian wall paintings. (Thing: Baglioni, P., R. Giorgi and C. C. Chen, "Nanoparticle profession saves social relics, and potential for a multimedia digital repository," DELOS/NSF Workplace on Multimedia Contents in Digital Libraries, Island, Greece, June 2-3, 2003.)
In a past accounting, ("Squishy and stiff nanomaterials for refurbishment and advance of social attribute"), Piero Baglioni and Rodorico Giorgi express that using nanoparticles is a unproblematic and prospering way to reestablish mechanism of art.
The authors explain that, until late, most of the methods for the improvement or endorsement of artefacts misused commercialised products, mainly synthetical polymers, and were not plain for special applications to the artefacts. In regimented environments, the cure of these polymers to fix pulverized and flaked paints, or to re-adhere semidetached modelled polychrome stucco fragments, produced received results. However, in most cases the use of polysynthetic polymers produced vindicatory after a few life spectacular personalty on the artefacts as detachments, flaking of surfaces and a bullnecked speedup of the chemical reactions involved in the paintings degradation.
Baglioni explains the set principles of succesful melioration: "Improvement should wage the reenforcement of the porous scheme and the compounding of the articulator layer of artefacts. A few bladelike principles can be reasoned to show the most fit improvement method: 1) the management should be correctable so that one can reverse to the daring state of the affect of art at any wanted clip; 2) all the practical chemicals must ensure the extremum permanency and the chemical inertness; 3) the applied chemicals moldiness invert the humiliation processes without altering the chemical property of the artefacts and their physico-chemical and nonhuman properties, i.e. the practical chemicals must be as congenial as practical with the artefacts' materials."
Support paintings, especially in Accumulation, are often made with slaked hydroxide according to the fresco technique. Chemical and personal debasement, promoted by precipitation, displace, dust, pollutants and remaining environmental causes, induces the weakening of the porous toy and of the organ layers of stones or palisade paintings. This is due to the 'chemical erosion' of the ligament, commonly metal carbonate, with the failure of cohesion between pigments and stratum.
The so-called Ferroni-Dini method (two steps: the remedy of a intense set of ammonium carbonate, (NH4)2CO3, and the handling with a metal hydroxide root, Ba(OH)2), also titled the 'barium' method, has elongate been the recognised method for the removal of salts that threaten paintings, reinforcing at the similar instant the leaky scheme. Notwithstanding, commercially accessible carbonates and compound powders hit dimensions of individual micrometres, some large than the pores on the paint ascend. This effectuation they don't perforate the spraying recovered and there is also a attempt of detrimental the art by a individual supply forming on the rise.
Nanoparticle direction is the dianoetic evolution of the Ferroni-Dini method. Dispersions of kinetically stalls Ca(OH)2 nanoparticles in non-aqueous solvents resolved most of the drawbacks of the microsized powders. Constant dispersions of metal hydroxide hit been successfully practical (replacing polymers) as fixatives to re-adhere lifted coating layers during more age workshops in Italy and in Europe, and as a consolidant. Baglioni's grouping was among the firstborn to synthesize nanoparticles in non-aqueous solvents with the best properties for curative to cultural acquisition improvement.
Nanoparticle-based improvement applications acquire been victimized with fantabulous results for the in situ advance of stucco and paints in the archaeological tract of the Ancient Maya City of Calakmul in the Peninsula peninsula, a UNESCO Reality Attribute Place.
Indian paintings in Calakmul. Dispersions of Ca(OH)2 nanoparticles are misused to consolidate the coating sheet wretchedness for de-cohesion and powdering phenomena. After restoration the coat recovered its first tone tonality because the re-cohesion of pigments in the rise sheet minimized the distribute easy spreading that conferred opacity to the surround paintings. (Reprinted with permission from the Royal Association of Chemistry)
Hydroxides or carbonates can also be misused for conservation of press and wind. Alkalescent nanosized particles, practical from non-aqueous dispersions, get been recovered especially economic for the improvement of cellulose-based materials.
Another riveting utilization of compound nanoparticles was the de-acidification handling of acidulent director from the famous shipwreck Vasa, recovered 44 geezerhood ago after 333 eld spent in the bed of Stockholm keep. Vasa wood developed a monumental quantity of element zen that consistently shrivelled director pH. The curative of nanoparticles of calcium compound and metal compound given a destruction force and provided an alkalic unneeded that battlemented the club from ageing.

my toothpaste with Nanotechnology?

noreply@blogger.com (Unknown) — Tue, 21 Jun 2011 20:28:00 -0700

Imagine a toothpaste that not only seeks out but actually repairs destroy to tooth enamel. For those who dread their annual visit to the dentist, this may sound like science fiction. For people in Japan, it is a reality. Using nanoparticles, Japan's Sangi Company, Ltd., has sold over 50 million tubes - & continues to expand its line of products containing nanoparticles. Scientists have learned to synthesize hydroxyapatite, a key part of tooth enamel, as nanosized crystals. When nano-hydroxyapatite is used in toothpaste, it forms a protective film on tooth enamel, & even restores the surface in damaged areas. Availability of similar products that claim to actually repair cavities is around the corner.

Toothpaste is among consumer products that contain nanoparticles

Unlikely as it seems at first blush, the $200 billion global cosmetics industry is of the major players in the emerging field of nanotechnology. According to the Centre for the Study of Environmental Change at Lancaster University in Britain, the cosmetics industry already holds the largest number of patents for nanoparticles - & be it toothpaste, sunscreen, shampoo, hair conditioner, lipstick, eye shadow, after shave, moisturizer or deodorant, the industry is leading the way.
reason for this is the very marketable area of anti-aging products. In 2004, the marketplace for these youth-promising skin care treatments was estimated at US$9.9 billion worldwide. New advances by nanotechnology are expected to drive that number up significantly. Take L'Oreal, which ranks sixth among nanotechnology patent holders in the U.S., with 200 nanotechnology patents according to Boston-based UTEK-EKMS, Inc. The cosmetics giant has developed a polymeric nanocapsule which guides active ingredients in to the lower layers of skin, increasing their efficacy. Although these fountain of youth products may be the most marketable & most profitable, L'Oreal & its competitors are also introducing nanoproducts that have been engineered to produce dramatic results of a different sort, such as eye shadow with more vivid colors & iridescent or metallic effects.
For years, the cosmetics industry has made a great deal of money by promotion beauty products. People require these things & cosmetics companies provide them - simple supply & demand. The issue with nanoengineered products is that no knows whether they are safe.

Nanoparticles can feign very antithetical chemical, corporeal and begotten properties than their normal-sized counterparts. This, coupled with the fact that these tiny particles can be absorbed finished the cutis or indrawn, is causing operative concern about the country of nanoparticles, especially those victimized in informal toiletries.
Tho' there is no expressed inform that nanocosmetics pose a health hazard, origin studies inform there may be large seek of nanoparticles temporary through the rind, into the bloodstream, and accumulating in paper and meat. It is believed that hearty wound provides an decent roadblock against particle sorption; nonetheless scraped, and plane flexed, pare may countenance particles to follow the body.
A assemble of researchers led by the Neurotoxicology Discord at EPA's (Environmental Endorsement Bureau) National Welfare and Environmental Effects Research Laboratory in the U.S. jazz studied the force of titania (titanium pollutant nanoparticles) in walk cells. The researchers rumored ("Metal Whitener (P25) Produces Activated Oxygen Species in Immortalized Intelligence Microglia (BV2): Implications for Nanoparticle Neurotoxicity") that the nanoparticles, which are currently victimized in sunblock products, falsify the cells' mean greeting to adventive particles. Rather than releasing a have of chemicals - oxidizable gas species (ROS) - to protect the mentality, the nanoparticles stimulate a slower resign of ROS, which could be potentially prejudicious to other intelligence cells. Else studies someone shown correspondent results in search. There is no aggregation to affirm that this type of oxidative
{Although this is one of much than 350 hit studies ("Calls Wave for Much Explore on Toxicology of Nanomaterials") currently underway at labs and academic institutions around the orb, scientists emphasize that these results are origination and untold solon explore must be done before an answer is institute. In an article publicised in Power ("Virulent Potential of Materials at the Nanolevel"), researchers at UCLA finished that though it is likely that engineered nanomaterials may make nephrotoxic personalty, there is less grounds to declare the personalty instrument cause a key difficulty that cannot be addressed by a noetic, technological motion. Although assured in science's knowledge to assure the safety of nanomaterials, these scientists also urge an prompt and proactive attack to area - which so far, hasn't happened in a large-scale and interconnected way.
In the meantime, numerous toiletry containing nanoparticles are already on the industry, and author are state introduced. A past list work institute statesman than 270 nanotechnology products already on the industry in 15 countries; umpteen of those were toiletries. These 270+ products may inform a fairly true show of the industry - or they may personify only a puny reckon of what's truly out there.
Because the toiletry manufacture is largely unregulated and cosmetics manufacturers are not required to give quantity labeling, more grouping may be exposing themselves to the country uncertainties of nanoparticles without educated it. At this doctor, consumers can bag their purchasing decisions only on advertising claims. And, piece nanotechnology is a general nonsense in marketing, not all products containing nanoparticles advertise their proximity.
The lack of substance nigh the safety of nanoparticles has generated fear among directional supranational regulatory agencies. In the U.S., the Matter and Ingest Governance (FDA) is currently considering whether a effort and empowerment system control the use of nanoparticles in toiletries should be implemented.
Crusader Concerns Get Louder
Friends of the Stuff (FOE), an outside mesh of grassroots environmental groups, is one of the most voiced advocates for stricter controls on products containing nanoparticles. The system is calling for a moratorium on specified products and the termination of those already on the marketplace, until decent bingle studies know been completed and regulations put in gauge.
In a past information ("Nanomaterials, sunscreens and cosmetics: Runty Ingredients, Big Risks", pdf download 4 MB), FOE criticizes regime agencies, including the FDA and the Royal Order in the UK, for their lack of activity concerning the business and merchantability of products containing nanoparticles. "The insolvency of regime regulators to bonk earnestly the azoic warning signs surrounding nanotoxicity suggests that they have learned null from any of the longer identify of disasters that resulted from the nonstarter to act to azoic warning signs around old detected 'wonder' materials (suchlike asbestos, DDT and PCBs)." Remaining organizations, including the Environmental Construction with business for nano-cosmetics that expectation low wrinkles or whiter set, the enticement may examine overwhelming. Whether the promises - or the risks - are sincere needs to be shown. Notwithstanding, until the potency risks are thoroughly premeditated, should the bark for smoother rind and flashier eye dominate conduct activity over eudaimonia and safety concerns?

nanotechnology startling landscapes

noreply@blogger.com (Unknown) — Tue, 21 Jun 2011 19:58:00 -0700

The nanoworld cannot be portrayed with a camera, nor can it be seen even with the most powerful optical microscope. Only special instruments have access to images of the nanoworld. A fascinating new exhibition "Blow-up: images from the nanoworld" in Modena/Italy shows the work of scientists associated with the National Middle on Nanostructures & Biosystems at Surfaces in Modena, France, headed by Elisa Molinari. The images have been manipulated in a variety of ways by photographer, Lucia Covi. Covi is sensible to the aesthetic paradigms of scientists: her gaze thus grasps essential aspects of the portrayed objects & lets her shine them with a brand spanking new light, as they are revealed now. This exhibition brings to the public images that are usually available to few, because they stay confined in the research laboratories, on the scientists' desks. The images are stills that, over time, have been put together from different framings, & that they can look at thanks to the mediation of machines. A number of them represent exceptional events, outstanding results that ended on the cover of scientific journals. Others were born from everyday research. All of them show a landscape that is being unraveled by scientists, scenery that is different from the they can see in the media, largely obtained through computer graphics & "artistic" interpretations, when not directly borrowed from science fiction.

Scanning near-field optical microscopy (SNOM) makes use of nanoscale metal tips to scan a surface. Here, a standard tip has been modified & sharpened to increase its precision. The tip in the midst of this structure measures a few tens of nanometers. (Picture: G.C. Gazzadi, S3 (INFM-CNR), Modena; P.Gucciardi, CNR-IPCF, Messina. Artwork: Lucia Covi)

Developing new instruments to be able to "see" at the nanoscale is a research field in itself. Shown here is the tip of an atomic force microscope (AFM), of the foremost tools for imaging, measuring & manipulating matter at the nanoscale. Here, a platinum electrode measuring hundredth of a nanometer has been deposited on the tip of this pyramid formed AFM tip by focused ion beam (FIB) deposition. (Picture: C. Menozzi, G.C. Gazzadi, S3 (INFM-CNR), Modena. Artwork: Lucia Covi)

Top view of a hole carved in a polyethylene surface. During a series of experiments the use of a FIB has proven to be very versatile and capable of carving various materials, including plastic. (Image: G.C. Gazzadi, S3 (INFM-CNR), Modena. Artwork: Lucia Covi)

Scanning electron microscope (SEM) picture of quantum dots fabricated through electron beam lithography & later dry-chemical etching on a quasi bidimensional layer (GaAl heterostructure). These structures are used to study the behavior of electrons, which are confined in to small spaces – approximate. ten electrons per dot. The diameter of each quantum dot is 200 nm (which means that a billion of these structure basically fit on the tip of your finger). (Picture: C.P. Garcia, V. Pellegrini , NEST (INFM), Pisa. Artwork: Lucia Covi)

SEM picture of a micron sized trench (10x 20x14 Âµm3) in a Cu/SiO2/Si multilayer, obtained through FIB milling. The precision of this method allows the visualization of ultrathin (tens of nanometers) layers. (Picture: G.C.Gazzadi, S.Frabboni, S3 (INFM-CNR), Modena. Artwork: Lucia Covi)

SEM picture of a work sample on a magnesium oxide surface using FIB. The diameter of the hole measures approximate. three Âµm. (Picture: G.C. Gazzadi, A. Spessot, S3 (INFM-CNR), Modena. Artwork: Lucia Covi)

Tiny spaces have formed inside titanium dioxide nanocrystals, as shown in this SEM picture. The square structure of these inside spaces, which measure between twenty nm & 40 nm, is due to the crystalline structure of the material. (Picture: L. Nasi, IMEM (CNR), Parma. Artwork: Lucia Covi)

Gecko nanotechnology

noreply@blogger.com (Unknown) — Mon, 20 Jun 2011 19:24:00 -0700

Animals that cling to walls & walk on ceilings owe this ability to micro- & nanoscale attachment elements. The highest adhesion forces are encountered in geckos. A gecko is the heaviest animal that can 'stand' on a ceiling, with its feet over its head. This is why scientists are intensely researching the adhesive technique of the small hairs on its feet. On the sole of a gecko's toes there's some billion small adhesive hairs, about 200 nanometers in both width & length. These hairs put the gecko in direct physical contact with its surroundings. The shape of the fibers is also significant; for example, spatula-shaped ends on the hairs provide strong adhesion. Researching how insect & gecko feet have evolved to optimize adhesion strength is leading to bio-inspired development of artificial dry adhesive systems. Potential applications range from protective foil for delicate glasses to reusable adhesive fixtures - say goodbye to fridge magnets, here comes the hairy stuff, which will also stick to your mirror, your cupboard & your windows.
Researchers at the Max Planck Institute for Metals Research in Stuttgart/Germany have explored the bizarre adhesion force of gecko feet for some time now. Back in 2004 they found that there exists an optimal shape of the contact surface of the tip of such hairs which gives rise to optimal adhesion to a substrate by molecular interaction forces ("Shape insensitive optimal adhesion of nanoscale fibrillar structures").

The nanoscale fibrillar structures in the hairy attachment pads of beetle, fly, spider & gecko. The density of surface hairs increases with the body weight of animal, & the gecko has the highest density among all animal species. (Picture: Max Planck Institute for Metals Research/Gorb)

For macroscopic objects, such optimal shape design tends to be unreliable because the adhesion strength is sensitive to small geometrical variations. It is shown that this limitation can be remedied by size reduction.
The key finding of this research is that there exists a critical contact size around 100 nanometers below which optimal adhesion can be reliably achieved independent of small variations in the shape of the contact surface. In general, optimal adhesion can be achieved by a mix of size reduction & shape optimization. The smaller the size, the less significant the shape.
This result provides a believable explanation why the characteristic size of hairy attachment systems in biology fall in a narrow range between a few hundred nanometer & a few micrometers & suggests a few useful guidelines for designing adhesive structures in engineering.
Continuing this research, in 2005 the Max-Planck researchers discovered that the adhesiveness of geckos increases with the amount of humidity ("Evidence for capillarity contributions to gecko adhesion from single spatula nanomechanical measurements" & "Resolving the nanoscale adhesion of individual gecko spatulae by atomic force microscopy").
Its foot's adhesive method, whose branches become increasingly smaller over levels, allows the gecko to stick to any ceiling & walk with its feet over its head. Until then, scientists were uncertain as to what mechanism was responsible for the extreme adhesive ability of the gecko. What was clear is that the adhesive method was in other words, that it functioned without secreting anything of its own. In lieu, it makes use of water, which is present as a narrow film on every terrestrial surface.
The researchers found that as humidity increases, the capillary forces strengthen & that ultra-thin water layers, like those between a gecko spatula & a substrate, influence the strength of adhesive forces.
Copying the biological adhesive mechanism, the Max-Planck scientists used the insights gained from their years of research to create a material with a biomimetic structure that exhibits excellent adhesive qualities. The special surface structure of the material allows it to stick to smooth walls without any adhesives. Potential applications range from reusable adhesive tape to shoe soles for climbing robots & are therefore of considerable relevance to expertise.

Microscope picture of the biomimetic surface structure of the new adhesive material. The material (green), which was inspired by the soles of insects' feet, sticks to the glass (blue). (Picture: Max Planck Institute for Metals Research)

In rigorous tests carried out by the Max Planck researchers with measuring instruments developed for the purpose, the artificial adhesive technique gave an impressive performance & demonstrated lots of benefits. It lasts for hundreds of applications, does not leave any visible marks & can be thoroughly cleaned with soap & water. The researchers found that square centimeters of the material can hold objects weighing up to hundred grams on walls. However, this limit is much lower for ceilings. Smooth structures, such as glass or polished wood, are nice bases but woodchip wallpaper is not suitable.
"Insects also struggle to travel over slightly roughened surfaces - it is a essential issue for adhesion mechanisms," explained Project Leader Stanislav Gorb from the Evolutionary Biomaterials Group at the Max-Planck-Institute for Metals Research.
To manufacture the material, a mold, similar to a cake tin in baking, is used in which the necessary surface is embossed as a negative picture. The mould is filled with a polymerizing mixture which is allowed to cure & then released from the mould. This sounds simple, but is the result of a "great deal of trial & error." The researchers found the construction of the microstructural "cake tin" challenging & exactly the way it works remains a trade secret. Optimizing the polymer mixture also taxed the researchers: if it is liquid it runs out of the mold; if it is viscose, it won't even go in.
Potential applications range from protective foil for delicate glasses to reusable adhesive fixtures. For example, the new material will soon be present in industrial production processes in the manufacture of glass parts. It's already been shown to perform in higher weight categories: the artificial adhesive fibers on the soles of a 120 gram robot helped it to climb a vertical glass wall ("Climbing & Jogging Robots : Proceedings of the 8th International Conference on Climbing & Jogging Robots & the Support Technologies for Mobile Machines").
In their current research, the scientists are trying to improve the adhesion by refining the structures even further.
"However, there is still lots of work to be completed. Something that functions smoothly in the laboratory is a long way away from large-scale production," explained Stanislav Gorb.

nanotechnology's Sizing up the science, politics and business of

noreply@blogger.com (Unknown) — Mon, 20 Jun 2011 18:52:00 -0700

nanotechnology's Sizing up the science, politics and business.

Nano-this and nano-that. Nanotechnology moves in to the public consciousness. This-nanotrend. has assumed "mega" proportions: Patent offices around the globe are swamped with nanotechnology-related applications; investment advisors compile nanotechnology stock indices and predict a coming boom in nanotechnology stocks with estimates floating around of a trillion-dollar industry within ten years; pundits promise a new world with radically different medical procedures, manufacturing technologies and solutions to environmental problems; nano conferences and trade shows are prospering all over the world; scientific journals are awash in articles dealing with nanoscience discoveries and nanotechnology breakthroughs. Nanotechnology has been plagued by lots of hype, but cynicism and criticism have not been far behind. The media can run amok when news about potential health issues with nanoproducts surface (as recently happened with a product recall for a toilet cleaner in France). These discussions around nanotechnology epitomize the contemporary processes of making the future present. An fascinating approach to dealing with the shortage of consensus in the views on nanotechnology identifies four main nodes of nanotechnology discourse and describes these "islands" of discussion, examines their interactions and degrees of isolation from each other.

In a recent paper in the journal Futures ("A map of the nanoworld: Sizing up the science, politics, & business of the infinitesimal") attempts to identify how scientists, policymakers, entrepreneurs, educators, & environmentalists have drawn boundaries on issues relating to nanotechnology; describes concisely the perspectives from which these boundaries are drawn; & explores how boundaries on nanotechnology are marked & negotiated through contestations of power among various nodes of nanotechnology discourse.
The method of demarcating boundaries starts with the definition of nanotechnology. Preliminary conceptions of nanotechnology were far more radical than currently realized & even thought about realizable by lots of technoscientists. Molecular manufacturing, self-replicating miniature robots, etc., were conceived of as constituting what their proponents call true nanotechnology. But there is a immense gap between the basic nanostructured materials being manufactured today & the potential of productive nanosystems.
Debashish Munshi, Associate Professor in Management Communication at the Waikato Management School in Hamilton, New Zealand, & lead author of the paper, explains to Nanowerk that the authors' analysis of tshe literature on nanotechnology reveals the following five nodes of societal discussion on nanotechnology:

(1) technoscientists, especially those either working on or supervising some nanotechnological application who, almost invariably, tend to glorify nanotechnology;
(2) leaders of business and industry who want to cash in on the projected benefits by developing a market for nanotechnology-driven products;
(3) official or quasi-official bodies that generate a significant amount of literature;
(4) social science and humanities researchers who tend to focus on the social, economic, political, legal, religious, philosophical, and ethical implications of nanotechnolgy;
(5) fiction writers with imaginative scenarios, both utopian and dystopian;
(6) political activists, particularly those with an environmental worldview, who tend to extend to nanotechnology the issues long raised by them with regard to biotechnology;
(7) journalists and popular science writers who report on current events, perspectives, and funding regimes relating to the field; and
(8) John Q. and Jane D. Public, who are yet to significantly grapple with or discuss nanotechnology
in any depth. Here are the key points from this paper:

Node 1: Technoscientists

It seems that nanotechnology is suddenly everywhere in technoscientific circles. Most of the technoscientific literature is glib enough to not indicate possible failures. This is normal in technoscientific literature because the emphasis is on publishing positive and upbeat results whereas negative issues are considered as unnecessary distractions.
As of early 2006 there are at least 25 print journals and at least one virtual journal that are either wholly or substantially dedicated to nanotechnology, in addition to a vast array of other scientific and technical journals that occasionally publish accounts of nanotechnology research. The authors note that the (British) Institute of Physics’ Nanotechnology is perhaps the only technoscientific journal that has occasionally published articles not written by nanotechnology researchers. Of these articles, there is only one on socioethical issues emanating from possible industrial and economic success in nanotechnology.
Node 2: Leaders of business and industry
It seems that business has so far warmed up to the idea of investing in enterprises seeking the improvement of existing products (through evolutionary nanotechnology) and not so much to the creation of fundamentally new materials and applications (the revolutionary nanotechnology). Claims of improvement are most common for the paint and the cosmetics industries, as well as for their user industries. Semiconductor industries are also beginning to claim the benefits of nanolithography for shrinking device sizes and increasing packing densities in integrated chips. Many of the claimed advances are not only real but also cost effective; but these advances fall in the realm of incremental nanotechnology, which is far from revolutionary.
Venture capitalists, seeking to invest large amounts of liquid cash for relatively quick profits, generally form partnerships with university researchers with an entrepreneurial bent. Nano start-up companies are based on a key patent or two, and the capital supplied by the venture capitalists is then invested to turn the patents into marketable products.
The companies that are making significant investments in nanotechnology are ones that already have vast experience in the technology sector. Not surprisingly, BASF, Dow Chemical, DuPont, General Electric, Hewlett-Packard, IBM, and NEC hold most of the nanotech patents. Most of these companies are involved in incremental nanotechnology but hold out for a molecular revolution that will change the face of business.
Node 3: Official and quasi-official bodies
A significant "official" literature has been generated by government agencies, international governmental organizations, and government-supported science and technology academies. This activity was undoubtedly generated as nanotechnology is widely seen as having huge potential for many areas of research and application, and is attracting investments from governments and from businesses. Furthermore, nanotechnology raises new challenges in the safety, regulatory or ethical domains that will require societal debate.
The paper notes that "collectively, the many government and official reports that constitute the node of this serious discourse can be and are accessed across most of the other nodes, although most official reports themselves only acknowledge and explicitly draw upon the technoscientific and business discourse nodes (as well as other official reports)."
Node 4: Social science and humanities research
Some early scholarly researchers from the social sciences and humanities have attempted to explore the social, economic, political, legal, religious, philosophical, and ethical implications of nanotechnology for human societies, but these researchers have not produced literatures yet, nor have they coalesced into functioning research communities. This discourse node is still in a very early stage of development, which can be seen in its almost entirely outward focus – rarely do the scattered writings cite other published scholarly works in the humanities and social sciences, in part because even as late as 2005 there is still little to be cited.
Node 5: Fiction writers
Fiction writers from early on have explored the potentials of nanotechnology, raising questions that have in some instances then been taken up in other nodes. Almost all of the emergent science fiction on nanotechnology has been based on the concerns of current science, even as it stretches any scientific consensus on what is plausible.
Node 6: Political activists
A good example for activist groups is ETC (the Action Group on Erosion, Technology and Concentration), a Canada-based activist group, which has produced a series of influential reports on the social implications of nanotechnology.
Activists – who have been politicized by policy debates over genetic modification of organisms – contribute in-depth reports, opinion pieces, and polemics to periodicals and mainstream media outlets such as the New York Times as well as to their own websites.
The varied activist reports and websites devoted to nanotechnology do monitor and respond to developments in Nodes 1 and 3, but with limited impact as yet on policy. It is primarily when their concerns get magnified through attention from the mainstream popular press that we see some acknowledgement from the technoscientists and government research-funding bodies.
Node 7: Science journalists and popular science writers
In terms of sheer volume, much of the writing in this category consists of short reports on current developments in nanotechnology. Much less common is critical journalism that looks at the current nanohype with any degree of skepticism. Just as research on the ethical implications of nanotechnology is scarce, as discussed for Node 4, reporting on the issue is generally confined to relatively brief statements about funding or legislative measures to deal with ethical issues.
Node 8: General public
The general public is, at best, dimly aware of the dimensions of nanotechnology, although the awareness is slowly growing, partly in response to initiatives taken by various governmental and nongovernmental groups. Although scant, the public’s view of nanotechnology probably differs from country to country, depending on national scientific aspirations and climate.
Implications
The authors make the interesting point that "it has long been well established by social scientists that technologies can be political – sometimes because certain technologies provide a convenient means of establishing patterns of power and authority, but sometimes because intractable properties of technologies are inherently linked to certain patterns of power and authority. It is certainly possible, perhaps likely, that the nanotechnology that emerges in coming years will have identifiable political qualities."
"That the power to define what is or what is not nanotechnology rests with technoscientists already points to a discursive power imbalance. It is this very power that privileges the technological aspects of a little-understood field over the social and cultural aspects. Riding piggy-back on this power of technoscientists are the captains of business and industry who are determined to capitalize on the lure of the label of nanotechnology."Munshi and his colleagues argue that "challenging the power imbalances implicit and explicit in society will require education of technoscientists, politicians, economists, lawyers, social scientists, school teachers, and indeed every citizen. Ignorance about the various facets and implications of progress in nanotechnology being widespread, a program of general education and information is essential in today’s industrial societie."

nanofabrication of armor Nature's bottom-up

noreply@blogger.com (Unknown) — Mon, 20 Jun 2011 18:37:00 -0700

nanofabrication of armor Nature's bottom-up .

Seashells are natural armor materials. The necessity for toughness arises because aquatic organisms are subject to fluctuating forces & impacts in the work of motion or through interaction with a moving surroundings. Nacre (mother-of-pearl), the pearly internal layer of plenty of mollusc shells, is the best example of a natural armor material that exhibits structural robustness, despite the brittle nature of their ceramic constituents. This material consists of about 95% inorganic aragonite with only a few percent of organic biopolymer by volume. New research at the university of South Carolina reveals the toughening secrets in nacre: rotation & deformation of aragonite nanograins absorb energy in the deformation of nacre. The aragonite nanograins in nacre are not brittle but deformable. The new findings may lead to the development of ultra-tough nanocomposites, for example for armor material, by realizing the rotation mechanism.

Super-tough and ultra-high temperature resistant materials are in critical need for applications under extreme conditions such as jet engines, power turbines, catalytic heat exchangers, military armors, aircrafts, and spacecrafts. Structural ceramics have largely failed to fulfill their promise of revolutionizing engines with strong materials that withstand very high temperature. The major problem with the use of ceramics as structural materials is their brittleness. Although many attempts have been made to increase their toughness, including incorporation of fibers, whiskers, or particles, and ZrO2 phase transformation toughening, currently available ceramics and their composites are still not as tough as metals and polymers. The brittleness of ceramic materials has not yet been overcome. It has proven difficult to solve this problem by conventional approaches.
On the other hand, Nature has evolved complex bottom-up methods for fabricating ordered nanostructured materials that often have extraordinary mechanical strength and toughness. One of the best examples is nacre. It has evolved through millions of years to a level of optimization not currently achieved in engineered composites.
This material has a brick-and-mortar-like structure with highly organized polygonal aragonite platelets of a thickness ranging from 200 to 500 nm and an edge length about 5 µm sandwiched with a 5-20 nm thick organic biopolymer interlayer, which assembles the aragonite platelets together. The combination of the soft organic biopolymer and the hard inorganic calcium carbonate produces a lamellar composite with a 2-fold increase in strength and a 1000-fold increase in toughness over its constituent materials.
Such remarkable properties have motivated many researchers to synthesize biomimetic nanocomposites that attempt to reproduce nature’s achievements and to understand the toughening and deformation mechanisms of natural nanocomposite materials.

Dr. Xiaodong Li, who heads the Nanostructures and Reliability Laboratory at the University of South Carolina, and his team have published papers that examine the role of nanostructures in the brilliant properties of nacre. In a first paper (" Nanoscale Structural and Mechanical Characterization of a Natural Nanocomposite Material: The Shell of Red Abalone"), the group reported the discovery of nanosized grains (particles) in nacre. However, the functionality of these aragonite nanograins was entirely unknown. Subsequently, lots of research groups asked: What roles do the nanoscale structures play in the inelasticity and toughening of nacre? Can they learn from this to produce nacre-like nanocomposites?
In a recent follow-up paper, Li and his group now reveal the functionality of these aragonite nanograins. The paper is titled "In Situ Observation of Nanograin Rotation and Deformation in Nacre", which appeared in the September 14, 2006 online edition of Nano Letters.
"To reveal the secret recipe of nacre is not an simple job" Li explains his research to Nanowerk. "We developed a micro-mechanical tester that can be used inside an atomic force microscope. They performed tensile and bending tests on nacre in situ where the nacre surface was imaged simultaneously by the atomic force microscope. The discoveries - rotation and deformation of aragonite nanograins clarify the earlier misunderstandings in modeling work, and provide a nanoscale modeling boundary condition. This opens up opportunities to create nacre-like ultra hard materials."
The grain rotation and deformation mechanisms in nacre aragonite platelets can be summarized by this figure:

On tension, the biopolymer between the nanograins is stretched in the tensile direction, which allows space for definite grains to rotate. Since the shape of these nanograins is normally irregular, the rotation of individual nanograins will push their neighbor grains apart, thereby leading to an increase in the spacing between the rotated nanograins and their neighbor grains (as shown in b).

With no outside applied strain/stress, nanograins with irregular shapes are originally packed closely by the biopolymer adhesives to form a sturdy structure (as shown in a).

The spacing behavior between the nanograins within an aragonite platelet causes the aragonite platelet to expand in the direction perpendicular to that of the applied strain/stress.
Schematics of grain rotation and deformation mechanisms in an aragonite platelet. D denotes grain deformation. The blue arrows denote the tensile direction. Green arrows denote the rotation direction of grains.(Reprinted with permission from the American Chemical Society)
The new findings are expected to revolutionize the way of preparing hard ceramic materials and structural parts, and will open up new application opportunities of ceramic materials and other materials as well.
Li points out that Nature has long been using bottom-up nanofabrication methods to form self-assembled nanomaterials that are much stronger and tougher than lots of manmade materials formed top-down.
"Mother Nature knows best" Li says. "Nature has evolved highly complex and elegant mechanisms for materials design and synthesis. Living organisms produce materials with physical properties that still surpass those of analogous synthetic materials with similar phase composition. They must turn our attention to Nature's designs and fabrication of materials. There is still a lot they must learn from Nature."

the wunderkind nanotechnology in pharmaceutics: Creating multifunctional nanocarriers

noreply@blogger.com (Unknown) — Mon, 20 Jun 2011 18:24:00 -0700

the wunderkind nanotechnology in pharmaceutics: Creating multifunctional nanocarriers.

The last few years saw tremendous progress in the use of nanoparticles to enhance the in vivo efficiency of many drugs. Currently used pharmaceutical nanocarriers, such as liposomes, micelles, nanoemulsions, polymeric nanoparticles and many others demonstrate a broad variety of useful properties, such as for instance increased longevity in the blood, specific targeting to certain disease sites, or enhanced intracellular penetration. Some of these pharmaceutical carriers have already made their way into clinics, while others are still under preclinical development. In the next phase of developing nanocarriers, researchers are intrigued by the possibility to synthesize pharmaceutical nanocarriers that possess not only one but several properties. Such particles can significantly enhance the efficacy of many therapeutic and diagnostic protocols. A brandnew review paper considers current status and possible future directions in the emerging area of multifunctional nanocarriers with primary attention on the combination of such properties as longevity, targetability, intracellular penetration and contrast loading.

Vladimir P. Torchilin, Distinguished Professor of Pharmaceutical Sciences and Director of the Center for Pharmaceutical Biotechnology and Nanomedicine at Northeastern University, described to Nanowerk how such nanocarriers would work: "One may want to have a drug-loaded nanocarrier demonstrating the following set of properties: (a) prolonged circulation in the blood; (b) ability to accumulate – specifically or non-specifically – in the required pathological zone, (c) responsiveness to local stimuli, such as pH and/or temperature changes, resulting, for example, in accelerated drug release, (d) allow for an effective intracellular drug delivery and further to individual cell organelles, and (e) bear a contrast/reporter moiety allowing for the real-time observation of its accumulation inside the target. Some other, more exotic properties can be added to the list, such as magnetic sensitivity."

In order to prepare such a smart multifunctional pharmaceutical nanocarrier, chemical moieties providing certain required individual properties have to be simultaneously assembled on the surface of the same nanoparticle. Moreover, these individual moieties have to function in a certain coordinated way to provide a desired combination of useful properties.

Torchilin cautions that systems like these still represent quite a challenge to researchers.

The schematic structure of the assembly of the multifunctional pharmaceutical nanocarrier. 1 – Traditional “plain” nanocarrier (a – drug loaded into the carrier); 2 – targeted nanocarrier or immunocarrier (b – specific targeting ligand, usually a monoclonal antibody, attached to the carrier surface); 3 – magnetic nanocarrier (c – magnetic particles loaded into the carrier together with the drug and allowing for the carrier sensitivity towards the external magnetic field and its use as a contrast agent for magnetic resonance imaging); 4 – long-circulating nanocarrier (d – surface-attached protecting polymer (usually PEG) allowing for prolonged circulation of the nanocarrier in the blood); 5 – contrast nanocarrier for imaging purposes (e – heavy metal atom – 111In, 99mTc, Gd, Mn – loaded onto the nanocarrier via the carrier-incorporated chelating moiety for gamma- or MR imaging application); 6 – cell-penetrating nanocarrier (f – cell-penetrating peptide, CPP, attached to the carrier surface and allowing for the carrier enhanced uptake by the cells); 7 – DNA-carrying nanocarrier such as lipoplex or polyplex (g – DNA complexed by the carrier via the carrier surface positive charge); 8 – hypothetical multifunctional pharmaceutical nanocarrier combining the properties of the carriers # 1–7. (Reprinted with permission from Elsevier)
Multifunctional nanocarriers need to possess a number of basic properties to make them effective and efficient:
Longevity in the blood
Nanoparticles are normally attacked as foreign substance by the body's defense system and removed from circulation long prior to completion of their function. Thus, the basic property of any multifunctional nanocarrier is its longevity, and long-circulating pharmaceuticals and pharmaceutical carriers represent currently an important and still growing area of biomedical research.
Chemical modification of pharmaceutical nanocarriers with certain synthetic polymers, such as polyethylene glycol (PEG), is the most frequent way to impart the in vivo longevity to drug carriers. The term “steric stabilization” has been introduced to describe the phenomenon of polymer-mediated protection. On the biological level, coating nanoparticles with PEG sterically hinders interactions of blood components with their surface and reduces the binding of plasma proteins with PEGylated nanoparticles. This prevents drug carrier interaction with opsonins and slows down their fast capture by the reticuloendothelial system (RES).
Several other polymers have also been suggested as alternative steric protectors for nano drug carriers and there is a lot of ongoing research in this area. These polymers are expected to be biocompatible, soluble, hydrophilic, and with a highly flexible main chain.
In summary, the most significant biological consequence of nanocarrier modification with protecting polymers is the sharp increase in its circulation time and decrease in their RES accumulation.
Targetability
To increase the functionality of pharmaceutical nanocarriers involves adding the property of the specific target recognition to the carrier's ability to circulate long, i.e. simultaneously attach both the protecting polymer and the targeting moiety on the surface of the nanocarrier. Targeting of drug carriers with the aid of ligands specific to cell surface-characteristic structures allows for the selective drug delivery to those cells. To obtain “simple” targeted nanocarriers, a variety of methods have been developed to attach corresponding vectors (antibodies, peptides, sugar moieties, folate, and other ligands) to the carrier surface.
Stimuli sensitivity
An additional function that researchers are keen to add to long-circulating PEGylated pharmaceutical carriers will allow for the detachment of protecting PEG chains under the action of certain local stimuli characteristic of pathological areas, such as decreased pH value or increased temperature usually noted for inflamed areas.
The problem here is that the stability of PEGylated nanocarriers may not always be favorable for drug delivery. For instance, if drug-containing nanocarriers accumulate inside a tumor, they may be unable to easily release the drug to kill the tumor cells. In order to solve these problems, for example, in the case of long-circulating liposomes, the chemistry was developed to detach PEG from the lipid anchor in the desired conditions.
As a result, polymeric components with pH-sensitive (pH-cleavable) bonds are used to produce stimuli-responsive drug delivery systems that are stable in the circulation or in normal tissues, however, acquire the ability to degrade and release the entrapped drugs in body areas or cell compartments with lowered pH, such as tumors, infarcts, or inflammation zones.
Intracellular delivery

Many biologically active compounds, including macromolecular drugs, need to be delivered intracellularly, for instance for gene therapy, to exert their therapeutic action inside the cell onto nucleus or other specific organelles, such as mitochondria. However, the lipophilic nature of the biological membranes restricts the direct intracellular delivery of such compounds.

Current delivery systems, be they viral or non-viral, all have drawbacks, such as for instance non-specificity and cytotoxic reactions, which makes them quite ineffective for clinical use. Researchers therefore have focused on the development of a new method that can deliver genetic constructs directly into the cytoplasm of the target cells. These include: the application of bimetallic nanorods that can simultaneously bind compacted DNA plasmid and targeting ligands in a spatially defined manner; membrane-destabilizing lipid components and anionic polymers; functionalizing drugs with proteins and peptides that demonstrate a unique ability to penetrate into cells (“protein transduction” phenomenon) and therefore may serve as a "transport" through the cell membrane.
Contrast moiety for visualization
To make it possible to use pharmaceutical nanocarriers for diagnostic/imaging purposes as well as to allow for their real-time biodistribution and target accumulation, contrast reporter moieties can be added to multifunctional nanocarriers to enable imaging modalities such as magnetic resonance, computer tomography or ultra-sonography.
Nanocarriers are able to carry multiple contrast moieties for an efficient delivery of contrast agents to areas of interest and enhancing a signal from these areas. Among nanocarriers for contrast agents, liposomes and micelles draw a special attention because of their easily controlled properties and good pharmacological characteristics. For instance, liposomes may incorporate contrast agents in both internal aqueous compartment and membrane.
Unlimited opportunities?
"As clearly follows from these examples, preparing multifunctional nanocarriers with controlled properties require the conjugation of proteins, peptides, polymers, cell-penetrating moieties, reporter groups and other functional ligands to the carrier surface; although, in certain cases, functional components may be loaded inside the nanocarrier or distributed within the nanocarrier structure" Torchilin explains. "This attachment can proceed non-covalently, via the hydrophobic adsorption of certain intrinsic or specially inserted hydrophobic groups in the ligands to be attached onto or into the surface of the nanocarrier. More frequently, the attachment is performed chemically, via the interaction of reactive groups generated on the carrier surface and certain groups in the molecule to be attached."
"Looking at all these developments, it becomes clear that multifunctional pharmaceutical nanocarriers could provide almost unlimited opportunities in producing highly efficient and specialized systems for drugs, genes, and diagnostic agents" Torchilin concludes. "Such multifunctional delivery systems with their individual functions acting in coordinated way should allow for delivery of pharmaceutical agents with required temporal and spatial deposition and release pattern. Although the approach is just emerging, it shows a promising future."

Community Members Euronanoforum in Hungary Attracts 1200 Nanotechnology

noreply@blogger.com (Unknown) — Mon, 13 Jun 2011 04:07:00 -0700

1200 members of the nanotechnology community from over 50 countries gathered in Budapest, Hungary, for days of presentations, networking & inspiration in the work of EuroNanoForum 2011. The event was supported by the European Commission & Hungarian National Innovation Fund, & was organised by the National Innovation Office in partnership with Spinverse under the auspices of the Hungarian Presidency.

The event was also able to contribute to the continued discussion about the future of nanotechnology both in terms of the continued work to support Key Enabling Technologies & the Common Strategic Framework. An industrial panel in the work of the closing plenary discussed ways in which public funding could contribute to the whole innovation pipeline, from research through demonstration to commercialisation & deployment.

The event drew together nanotechnologies which could contribute to the solution of grand challenges, including renewable energy, ageing populations, & resource efficiency. Presenters described hundreds of solutions such as nanoparticle-based cancer therapies, retinal & cochlear implants, nanomaterials for improving energy density of batteries & mass production of flexible solar cells, & materials to improve the performance & energy efficiency of electronics. A plenary presentation on the potential applications of graphene also underlined the fact that nanotechnology is being constantly expanded by new developments & discoveries.

The event hosted a venture capital session, where leading investors from Europe gave awards for start-up companies. The winner of Best Start-up Award was Nanoference from Denmark with its ambitious, disruptive business plan based on scientific discovery. Skeleton Technologies from Estonia got a special mention for a very well structured pitch. General observation from the session was that Europe is walking short of venture capital funds. More public funding & tax policies were expected to speed up growth of European start-ups. Research funding needs to be complemented with instruments that support also product development & business development.

Athanasios Skouras from University of Patlas received the EuroNanoForum 2011 award for the best poster introduced by a young researcher. An exhibition accompanied the event, at which 60 organisations introduced themselves. The best exhibitors, as voted for by attendees included NanoNext, the Netherlands nanotechnology network, the NMPTeAM network of national contact points, & Estonian electrospinning pioneer Esfil Tehno. A matchmaking event on 1st June also saw 425 meetings happen, stimulating networking for know-how transfer & for new project consortia.

Pekka Koponen, CEO of Spinverse, added that "the high interest in this event, & the number of exhibitors, industrial participants & close to market nanotechnology developments confirm our own research which shows that nanotechnology has become highly relevant for competitiveness & growth."

"This event has exceeded our expectations, & they were delighted to be able to host so plenty of members of the European nanotechnology community. Simultaneously this was a great opportunity to present Hungarian nanotechnology research activities & results to the European nanotechnology community. They hope the developments & discussions that have taken place in the work of this event will bear fruit for Europe in the coming years," commented Gyorgy Meszaros, President of the National Innovation Office of Hungary.

Researchers Create Improved Sodium-Manganese Oxide Re-chargeable Batteries Using Nanomaterials

noreply@blogger.com (Unknown) — Mon, 13 Jun 2011 03:11:00 -0700

A team of scientists at the Pacific Northwest National Laboratory of the Department of Energy are working together with researchers from the Wuhan University in China to manufacture electrodes using nanomaterials that can function well with sodium.

The electrodes in lithium rechargeable batteries consist of manganese oxide. When batteries are charged or in use, the atoms present in this metal oxide form numerous tunnels and holes and enable the free movement of lithium ions. The free motion of lithium ions allows the battery to either retain power or release it. Replacing the lithium ions with sodium ions is challenging. Sodium ions are 70% larger than lithium ions and do not accommodate well in the crevices.

Researchers tried to make larger holes in manganese oxide with the use of nanomaterials. These materials are about a million times smaller than a dime.

The team combined different types of atomic building blocks of manganese oxide of which block had atoms that arranged themselves in pyramids and the other block atoms that formed an octahedron and predicted that the resultant material would have huge S-shaped tunnels and little five-sided tunnels for ions to pass. Following the mixing, the team subjected the materials to temperatures from 450Â°C to 900Â°C. Next, they observed the materials and evaluated the most effective type of treatment.

With the help of a scanning electron microscope, the team found that the quality of material differed at different temperatures. When manganese oxide was treated at 750Â°C, it created the most effective crystals. When heated to 600Â°C, the nanowires featured pockmarks that could obstruct the sodium ions, but the 750Â°C-treated wires appeared even and crystalline.

The electrode was dipped in electrolyte comprising sodium ions enabling the electrodes to generate a current. They charged and discharged the new battery cells continually. The peak capacity was recorded as 128 mA/g of electrode in the coursework of discharge of the new battery cell.

Finally, the team charged the experimental battery cell at various speeds to choose the time it takes to take up electricity. The faster the battery got charged, the lesser electricity it could retain. Thus, it was established that the rate at which sodium ions diffused in to the manganese oxide restricted the capacity of the battery cell.

To Enforce Government Regulations Research Focuses on Health Hazards due to Nanomaterials

noreply@blogger.com (Unknown) — Mon, 13 Jun 2011 02:57:00 -0700

Occupational health and safety professional of the Southeastern Louisiana University is citing the gap in knowledge for state agencies to regulate the use of nanomaterials. Precautionary measures must be taken to deal with safety and health issues that arise owing to usage of nanomaterials of dimensions smaller than the width of a human hair.

The Assistant professor of occupational safety, health, and surroundings of southeastern Louisiana University, Ephraim Massawe, is inquiring in to the information and technical requirements of the country's state agencies and programs. They has started analyzing the nano-enhanced technologies and work practices implemented at several superfund sites of the Environmental Protection Agency (EPA). The Louisiana Board of Regents is supportive of the research work by providing grants at a value of very $110,000 for a three-year period.

Engineered nanoparticles have been used in several commercial and non commercial applications such as in medicine, manufacturing, and environmental remediation.

Massawe said that the manner in which nanomaterials may react with the environment and the human body is yet to be discovered. They said that animal studies recommend that definite nanomaterials may contribute to pregnancy complications and lung diseases. A complete survey will be conducted on state agencies and programs to set up the scientific information and technical requirements for regulatory and oversight purposes. The information collected will help state agencies and programs to manage the environmental and occupational exposures to nanomaterials.

The nanotechnology field is in its preliminary stages, Massawe said, and enforcement and regulations concerning the manufacture, disposal, and use of nanomaterials are in their evolution stage. They said that nanomaterials are currently used to eliminate harmful wastes such as organic contaminants. They is also studying the treatment process of dangerous wastes, the nature of nanomaterials used in treatment, the practices used to handle them and the sources of potential emission. They conducted this study along with specialists from the EPA, the national institute for occupational safety and health and the United Nations.

Massawe will study closely the use of definite engineered nanoparticles, such as titanium dioxide and their usage in tidy up activities at EPA Superfund sites. They said it is important to know how they are being handled in these sites and whether they may contaminate the air and pose as a health hazard to the nearby community. It is also feasible that they may enter water systems and turn out to be a threat for public health.

Nanopositioning Systems New Featuring Details Catalog by PI

noreply@blogger.com (Unknown) — Mon, 13 Jun 2011 02:35:00 -0700

PIs New Nanopositioning Systems Catalog

Physik Instrumente (PI), a company that manufactures high-accuracy motion-control devices and nanopositioning stages for semiconductor, bio-medical, nanotechnology and imaging applications, introduces a nanopositioning catalog.
The catalog consists of 160 pages and concentrates on nanopositioning systems based on piezo-flexure that can cover tiny distances as tiny as an atom diameter repetitively. It explains in detail about the ways to get multi-axis movement such as serial and parallel kinematics. Serial Kinematics is an simple and cost-effective process when compared to parallel kinematics. The catalog covers both XY and XYZ stages and tip/tilt platforms necessary for imaging, adaptive optics, nanometrology, scanning microscopy, and laser beam steering.

The company also manufactures piezo motors, piezo nanopositioning systems and actuators for a broad range of applications. The catalog offers details about piezo nanopositioning and scanning systems.

The catalog also features ceramic precision linear motors, innovative hybrid systems, and parallel kinematic positioners that are dual-axis systems with six-axis hexapods. A specific section of the catalog elaborates on digital nanopositioning controllers. This section explains about the application necessary, discusses interfacing options and various digital servo control algorithms and models to accomplish high levels of linearity in dynamic and static applications.

What is Nanotechnology?

noreply@blogger.com (Unknown) — Sat, 11 Jun 2011 15:53:00 -0700

Despite unprecedented government funding and public interest in nanotechnology, few can exactly define the scope, range or potential applications of this know-how. of the most pressing issues facing nanoscientists and technologists today is that of communicating with the non-scientific community. Because of decades of speculation, a few myths have grown up around the field, making it difficult for the general public, or indeed the business and financial communities, to understand what is a essential shift in the way they look at our interactions with the natural world. This editorial attempts to address a quantity of these misconceptions, and report why scientists, businesses and governments are spending giant amounts of time and funds on nanoscale research and development.

1. Introduction

Take a random choice of scientists, engineers, investors and the general public and ask them what nanotechnology is and you will receive a range of replies as broad as nanotechnology itself. For plenty of scientists, it is nothing startlingly new; after all they have been working at the nanoscale for plenty of years, through electron microscopy, scanning probe microscopies or basically growing and analysing narrow films. For most other groups, however, nanotechnology means something far more ambitious, miniature submarines in the bloodstream, little cogs and gears made out of atoms, space elevators made of nanotubes, and the colonization of space. It is no wonder people often muddle up nanotechnology with science fiction.

one. What is nanotechnology?

two. What is the nanoscale?

Although a metre is defined by the International Standards Organization as `the length of the path travelled by light in vacuum in the coursework of a time interval of 1/299 792 458 of a second' and a nanometre is by definition 10- 9 of a metre, this does not help scientists to communicate the nanoscale to non-scientists. It is in human nature to relate sizes by reference to everyday objects, and the commonest definition of nanotechnology is in relation to the width of a human hair.

Regrettably, human hairs are highly variable, ranging from tens to hundreds of microns in diameter (10-6 of a metre), depending on the colour, type and the part of the body from which they are taken, so what is necessary is a standard to which they can relate the nanoscale. than asking someone to imagine a millionth or a billionth of something, which few sane people can accomplish with ease, relating nanotechnology to atoms often makes the nanometre simpler to imagine. While few non-scientists have a clear idea of how giant an atom is, defining a nanometre as the size of ten hydrogen, or three silicon atoms in a line is within the power of the human mind to grasp. The exact size of the atoms is less significant than communicating the fact that nanotechnology is dealing with the smallest parts of matter that they can manipulate.

two. Science fiction

While there is a often held belief that nanotechnology is a futuristic science with applications 25 years in the future and beyond, nanotechnology is anything but science fiction. In the last 15 years over a dozen Nobel prizes have been awarded in nanotechnology, from the development of the scanning probe microscope (SPM), to the discovery of fullerenes. According to CMP CientÃfica, over 600 companies are currently active in nanotechnology, from little venture capital backed start-ups to a quantity of the world's largest corporations such as IBM and Samsung. Governments and corporations worldwide have ploughed over $4 billion in to nanotechnology in the last year alone. every university in the world has a nanotechnology department, or will have at least applied for the funding for.

Even more significantly, there's companies applying nanotechnology to a variety of products they can already buy, such as automobile parts, clothing and ski wax. Nanotechnology is already all around us in case you know where to look.

three. The nanotechnology industry

The confusion arises in part because plenty of people in the business world have no idea where to look. Over the last decade, know-how has become synonymous with computers, program and communications, whether the net or mobile rings. Plenty of of the preliminary applications of nanotechnology are materials related, such as additives for plastics, nanocarbon particles for improved steels, coatings and improved catalysts for the petrochemical industry. All of these are know-how based industries, possibly not new ones, but industries with multi-billion dollar markets.

It is increasingly common to listen to people referring to `the nanotechnology industry', like the program or mobile phone industries, but will such a thing ever exist? Plenty of of the companies working with nanotechnology are basically applying our knowledge of the nanoscale to existing industries, whether it is improved drug delivery mechanisms for the pharmaceutical industry, or producing nanoclay particles for the plastics industry. In fact nanotechnology is an enabling know-how than an industry in its own right. No would ever report Microsoft or Oracle as being part of the electricity industry, although without electricity the program industry could not exist. , nanotechnology is a essential understanding of how nature works at the atomic scale. New industries will be generated because of this understanding, as the understanding of how electrons can be moved in a conductor by applying a feasible difference led to electric lighting, the phone, computing, the net and plenty of other industries, all of which would not have been feasible without it.

While it is feasible to buy a packet of nanotechnology, a gram of nanotubes for example, it would have zero inherent value. The actual value of the nanotubes would be in their application, whether within existing industry, or to enable the creation of a whole new.

Shrinking machines down to the size where they can be inserted in to the human body in order to detect and repair diseased cells is a well-liked idea of the benefits of nanotechnology, and that even comes close to reality. Plenty of companies are already in clinical trials for drug delivery mechanisms based on nanotechnology, but regrettably none of them involve miniature submarines. It turns out that there's a whole range of more efficient ways that nanotechnology can enable better drug delivery without resorting to the use of nanomachines.

6. Fantastic voyage

the idea of navigating ones way around the body at will does not bear serious scrutiny. Imagine trying to go against the flow in an arteryâ��it would be like swimming upstream in a fast flowing river, while boulders the size of houses, red and white blood cells, rained down on you. Current medical applications of nanotechnology are far more likely to involve improved delivery methods, such as pulmonary or epidermal methods to keep away from having to pass through the stomach, encapsulation for both delivery and delayed release, and finally the integration of detection with delivery, in order for drugs to be delivered exactly where they are needed, thus minimizing side effects on healthy tissue and cells. As far as navigation goes, delivery will be by the exact same method that the human body makes use of, going with the flow and `dropping anchor' when the drug encounters its target.

7. Shrinking stuff

However, nanotechnology offers us a way out of this technological and financial cul-de-sac by building devices from the bottom up. Techniques such as self assembly, perhaps assisted by templates created by nano imprint lithography, a notable European success, combined with our understanding of the workings of polymers and molecules such as Rotoxane at the nanoscale open up a whole new host of possibilities. Whether it is avoiding Moore's second law by switching to plastic electronics, or using molecular electronics, our understanding of the behaviour of materials on the scale of little molecules allows a variety of alternative approaches, to produce smarter, cheaper devices. The new understandings will also let us design new architectures, with the final result that functionality will become a more valid measure of performance than transistor density or operations per second.

Another common misconception is that nanotechnology is primarily concerned with making things smaller. This has been exacerbated by images of little bulls, and miniature guitars that can be strummed with the tip of an AFM, that while newsworthy, merely demonstrate our new found control of matter at the sub-micron scale. While the whole focus of micro-technologies has been on taking macro-scale devices such as transistors and mechanical systems and making them smaller, nanotechnology is more concerned with our ability to generate from the bottom up. In electronics, there is a growing realization that with the finish of the CMOS roadmap in sight at around ten nm, combined with the uncertainly principal's limit of Von Neuman electronics at one nm, that merely making things smaller won't help us. Replacing CMOS transistors on a for basis with some type of nano tool would have the effect of drastically increasing fabrication costs, while offering only a marginal improvement over current technologies.

8. Nanotechnology is new

It often comes as a surprise to learn that the Romans and Chinese were using nanoparticles thousands of years ago. Similarly, every time you light a match, fullerenes are produced. Degusssa have been producing carbon black, the substance that makes automobile tyres black and improves the wear resistance of the rubber, since the 1920s. Of coursework they were not aware that they were using nanotechnology, and as they had no control over particle size, or even any knowledge of the nanoscale they were not using nanotechnology as currently defined.

What is new about nanotechnology is our ability to not only see, and manipulate matter on the nanoscale, but our understanding of atomic scale interactions.

9. Building atom by atom

of the defining moments in nanotechnology came in 1989 when Don Eigler used a SPM to spell out the letters IBM in xenon atoms. For the first time they could put atoms exactly where they wanted them, even if keeping them there at much above absolute zero proved to be an issue. While useful in aiding our understanding of the nanoworld, arranging atoms together after the other is unlikely to be of much use in industrial processes. Given that a Pentium two processor contains 42 million transistors, even simplifying the transistors to a cube of 100 atoms on each side would need 42 x 102 operations, and that is before they start to think about the other material and devices needed in a functioning processor.

Compare this with the difficulty of producing anything organic atom by atom, a sausage for example. Everyone is familiar with the macroscale ingredients of a sausage, some meat, possibly some fat, cartilage or other forms of tissue, even some bone, all encased in animal gut. Never mind, argue the proponents of assemblers, things are simpler at smaller scales.

Of coursework they already have the ability to build things atom by atom, and on a giant scale; it is called physical chemistry, and has been in industrial use for over a century producing everything from nitrates to salt. To do this, they do not need any kind of tabletop assembler as in Star Trek, usually a few barrels of obtainable precursor chemicals and possibly a catalyst are all that is necessary.

In terms of return on our investment, a farmyard containing a few pigs is a way more effective sausage machine than they could ever design, and has several other by-products such as hams and a highly effective waste disposal technique. This serves to illustrate how far they are away from being able to replicate nature.

Zooming down to the microscale they still have far more complexity than they would like to try to replicate, with cells, cytoplasm, mitochondria, chromosomes, ribosomes and plenty of other highly complex items of natural engineering. Moving closer to the nanoscale, they still must deal with nucleic acids, nucleotides, peptides and proteins, none of which they fully understand, or expect to even have the computing power to understand in the near future.

In terms of capturing the public imagination, unleashing hordes of self-replicating devices that escape from the lab and assault anything in their path is always going to be popular. Regrettably nature has already beaten us to it, by several hundred million years. Naturally occurring nanomachines, that can not only replicate and mutate as they do so in order to keep away from our best attempts at eradication, but can also escape their hosts and travel with alarming ease through the atmosphere. No wonder that viruses are the most successful living organisms on the planet, with most of their `machinery' being well in to the nano realm. However, there's finite limits to the spread of such `nanobots', usually determined by their ability, or lack thereof, of converting a sufficiently wide selection of material needed for future expansion. Indeed, the immune systems of plenty of species, while unable to neutralize viruses without side effects such as runny noses, are so effective in dealing with this type of threat because of the wide selection of different technologies obtainable to a immense complex organism when confronted with a single purpose nano-sized. For any threat from the nano world to become a danger, it would must include far more intelligence and flexibility than they could possibly design in to it.

ten. Assault of the killer nanobots

11. Conclusions

Our understanding of genomics and proteomics is primitive compared with that of nature, and is likely to stay that way for the foreseeable future. For someone determined to worry about nanoscale threats to humanity ought to think about mutations in viruses such as HIV that would permit transmission by mosquitoes, or deadlier versions of the influenza virus, which deserve far more concern than anything nanotechnology may produce.

Nanotechnology, like any other branch of science, is primarily concerned with understanding how nature works. They have discussed how our efforts to produce devices and manipulate matter are still at a primitive stage compared to nature. Nature has the ability to design highly energy efficient systems that operate exactly and without waste, fix only that which needs fixing, do only that which needs doing, and no more. They do not, although day our understanding of nanoscale phenomena may let us replicate at least part of what nature accomplishes with ease.

While plenty of branches of what now falls under the umbrella term nanotechnology are not new, it is the combination of existing technologies with our new found ability to observe and manipulate at the atomic scale that makes nanotechnology so compelling from scientific, business and political viewpoints.

For the scientist, advancing the sum total of human knowledge has long been the driving force behind discovery, from the gentleman scientists of the 17th and 18th centuries to our current academic infrastructure. Nanotechnology is at a early stage in our attempts to understand the world around us, and will provide inspiration and drive for plenty of generations of scientists.

For business, nanotechnology is no different from any other know-how: it will be judged on its ability to make funds. This may be in the lowering of production costs by, for example, the use of more efficient or more selective catalysts in the chemicals industry, by developing new products such as novel drug delivery mechanisms or stain resistant clothing, or the creation of entirely new markets, as the understanding of polymers did for the multi-billion euro plastics industry.

Possibly the greatest short term benefit of nanotechnology is in bringing together the disparate sciences, physical and biological, who due to the nature of schooling often have had no contact since high school. than nanosubmarines or killer nanobots, the greatest legacy of nanotechnology may well show to be the unification of scientific disciplines and the resultant ability of scientists, when faced with an issue, to call on the resources of the whole of science, not of discipline.

Politically, it can be argued that fear is the primary motivation. The US has opened up a commanding lead in terms of economic growth, despite recent setbacks, as a result if the growth and adoption of information know-how. Of equal significance is the lead in military know-how as demonstrated by the use of unmanned drones for both surveillance and assault in recent conflicts. Nanotechnology promises far more significant economic, military and cultural changes than those created by the net, and with know-how advancing so fast, and development and adoption cycles becoming shorter, playing catch-up won't be an option for governments who are not already taking action.

Back To Original Shape After Being Crumpled? Breakthrough Produces Metal Rubber Flexible Metal Sheets Snap by Nanotechnology

noreply@blogger.com (Unknown) — Sat, 11 Jun 2011 02:40:00 -0700

once its started, nothing will makes it stop, the nano even comes to Produces Metal Rubber Flexible Metal Sheets

Metal rubber is narrow and can be twisted, folded, or crumpled up, and then immediately snaps back to its original shape. It also conducts electricity like solid metal. This of work has all sorts of industrial applications, including use in consumer electronics, military and aircraft industries, and medical technologies as well. It also has applications in robotics, where metal rubber could be used for robotic skin or flexible circuits. It may even be useful for generating artificial muscles.

A breakthrough in material science has produced a highly pliable metallic substance called "metal rubber." This has been developed by a company called NanoSonic, and is the product of nanotechnology fabrication processes.

While I am not a gigantic fan of the over-hyped nanotechnology field, this particular product of nanotechnology looks promising. A material such as this might potentially revolutionize flexible circuits and make all electronics, whether in robots, medical devices, or airplanes, far more resilient and resistant to fatigue.

Nanotech will kill cancer cells by the Heat treatment

noreply@blogger.com (Unknown) — Sat, 11 Jun 2011 02:32:00 -0700

The Treatment No Mater it comes from the Nanotech or else, but the Nano can give you a hand with the cancer cells

The testes -- always a few degrees cooler than the remainder of the body -- are an ideal location for cancer cells, but proof suggests those cells die when they try to spread to other locations around the body.

Testicular cancer patients have a higher survival rate than other cancer patients because the cancer cells are sensitive to body heat, leading the researchers at Johns Hopkins University to conclude heat therapy could be a viable treatment for cancer.

"We tried to put our heads together about what they know about the differences between testicular and other cancers." Getzenberg said in the Journal of the American Medical Association. "There is an fabulous difference in treatment success, and they desired to come up with a simple idea that has a biological basis."

This leads Professor Robert Getzenberg and his colleagues to think the cancer cells would reply well to heat treatment in what they call the "Lance Armstrong effect," after the seven-time Tour de France winner who famously beat testicular cancer. Getzenberg and the other scientists are now experimenting with other heat-based methods of weakening cancer cells.

"These nanoparticles exist now and can be used in the body. The advantages are you don't must put them in every cell as long as you are getting a warming surroundings," Getzenberg said.

The issue with heat therapy would be targeting the cancer cells without doing any damage to the healthy cells. But nanotechnology could permit researchers to make use of ion particles on malignant cells directly by developing them to be drawn to specific markers on the surface of a cancer cell. Five times they bond with the cancer cells, the nanoparticles can be heated using a magnetic field.

Ed Yong, cancer information officer at Cancer Research UK, added, "Nanotechnology is a thrilling new field of science and it is set to play an increasing role in detecting and treating cancers."

But consumer health advocate Mike Adams disagrees. "You don't require nanotechnology or other technical hocus pocus to generate heat and damage cancer cells," they explains. "Just engage in regular physical exercise that makes you hot and produces a healthy sweat. Lance Armstrong didn't beat testicular cancer with nanotechnology, they beat it by pumping his legs on a bicycle."

food industry workers may exposure Nanotech ingredients to unknown health risks

noreply@blogger.com (Unknown) — Sat, 11 Jun 2011 02:25:00 -0700

The Nanotech still new after all, and Human's an enemy to what he's ignorant

According to Andrew Maynard, editorial author and chief science advisor to the Project on Emerging Nanotechnologies, an estimated three million workers will produce about $2.6 trillion worth of nanotechnology manufactured foods a year by 2015. They also quoted other research that predicted nanotechnology would be worth $16.4 billion to the food industry by 2010. According to the Project on Emerging Nanotechnology's online database, there's over 300 nanotechnology products already on the market, including foods, food packaging and dietary supplements.

A study recently published by the British Occupational Hygiene Society suggests that workers who manufacture nanotech foods -- foods containing nanoparticles that are expected to behave in a specific manner -- may be exposed to unknown health risks.

Maynard also complained that, while companies spend upward of $1 billion yearly on nanotech research, they only spend about $11 million on safety studies.

"The presence of engineered nanomaterials in the workplace today poses as an immediate challenge to how occupational safety and health is managed," Maynard said. "So far, they have a variety of red flags that indicate some engineered nanomaterials might present a new or unusual health hazard."

Studies of rats have found that discrete, nanometer-diameter particles could crossing the animals' blood-brain barrier in to the brain itself. Until the effects on humans are known, Maynard suggested nanotechnology businesses initiate "control banding", which would involve making a nanomaterial "impact index" template to assess appropriate risk control guidelines. The index would measure the risk of individual products based on particle size, shape and activity, as well as the amount of material and dustiness.

"This is still very much at the conceptual stage," said Maynard. "But unconventional issues require unconventional solutions, and these in turn will need a serious investment in relevant nanotechnology risk research.

Make Solar Electricity Cheaper Than Coal with Nanosolar

noreply@blogger.com (Unknown) — Sat, 11 Jun 2011 02:09:00 -0700

What makes you believe that you cant saving big money and your free to use your Electricity ?

everything is possible with the nanotech

"It's 100 times thinner than existing solar panels, and they can deposit the semiconductors 100 times faster," said Nanosolar's cofounder and chief executive officer, R. Martin Roscheisen. "It's a combination that drives down costs dramatically."

A new combination of nano and solar expertise has made it feasible for solar electric generation to be cheaper than burning coal. Nanosolar, Inc. has developed a way to produce a kind of ink that absorbs solar radiation and converts in to electric current. Photovoltaic (PV) sheets are produced by a machine similar to a printing press, which rolls out the PV ink onto sheets about the width of aluminum foil. These PV sheets can be produced at a rate of hundreds of feet per minute.

Because of their light weight and flexibility, the PV sheets (dubbed PowerSheets) are much more versatile than current PV panels, which must be mounted on sturdy surfaces like roofs or the ground. In addition, because there is no silicon used in the production of the sheets, they cost only 30 cents per watt of power produced.

Traditional PV cells cost about $3 per watt, while burning coal costs about $1 per watt.

Nanosolar is ramping up production of its PowerSheets at factories in San Jose, New york, and Berlin, and expects to have them commercially available before the finish of the year. The excitement around the PowerSheets is so strong that the company already has a to year backorder, and the company has raised over $150 million from venture capitalists, including Google cofounders Larry Page and Sergey Brin.

"This is the first time that they can actually drop the cost of solar electricity down to a level that would be competitive with grid electricity in most industrialized nations," said Nanosolar co-founder Brian Sager.

"Solar panels have not been popular to the American people because they have been pricey. That is what we are changing now," Roscheisen said.

too secretive nanoparticles Food industry

noreply@blogger.com (Unknown) — Sat, 11 Jun 2011 01:55:00 -0700

The industry is "very reluctant to put its head above the parapet and be open about research on nanotechnology," said study chairperson Lord John Krebs.

The food industry is being secretive about the extent to which it's adopted nanotechnology, according to a document by the United Kingdom's House of Lords Science and Expertise Committee.

"They got their fingers burnt over the use of GM crops and so they require to keep a low profile on this issue. They think that they ought to adopt exactly the opposite approach. In case you require to build confidence you ought to be open than secretive."

Nanotechnology refers to the practice of manipulating particles on the scale of one-billionth of a meter. Particles of this size behave in a fundamentally different fashion than they do on the more familiar scale, producing a wide range of novel applications. Because nanoparticles are not currently regulated any differently than larger particles, they are already making their way in to consumer products, from sunscreens and cosmetics to clothing and sporting goods. Their industrial and medical makes use of are also being explored.

It is "regrettable that the food industry [is] refusing to discuss its work in the area," the document says.

The food industry is inquiring in to ways that nanotechnology can be used for applications such as flavor or even nutritional enhancement, but has taken advantage of the regulatory loophole to keep these practices secret.

"We are not clear what is out there in use at the moment," Krebs said.

According to the Project on Emerging Nanotechnolgies, there's at least 84 food-related products making use of nanotechnology already. Yet due to industry secrecy, such numbers are necessarily speculative and probably underestimates.

The document estimates that the nanotechnology market will balloon from its current value of $410 million to over $4.1 billion in the next years.

treasure of the green nanotechnology might be in Cinnamon

noreply@blogger.com (Unknown) — Sat, 11 Jun 2011 01:51:00 -0700

(NaturalNews) Gold nanoparticles, so brilliantly tiny they can not be seen by the bare eye, are used in electronics, healthcare products and as pharmaceuticals in some cancer treatments. Regrettably, the positive applications of gold nanoparticles come with a downside -- producing the nanoparticles requires very poisonous chemicals and harmful acids. And, because the nanotechnology industry is expected to produce giant quantities of nanoparticles in the immediate future, serious concerns are being raised over the environmental impact of the global nanotechnological revolution and its current need for poisonous materials.

But now University of Missouri (UM) scientists have found a way to make "green" nanotechnology by replacing all of the poisonous chemicals necessary to make gold nanoparticles. How can this be accomplished? By using a spice present in most kitchens -- cinnamon.

There is another benefit, . "Our gold nanoparticles are not only ecologically and biologically benign, they are also biologically active against cancer cells," Dr. Katti announced in a statement to the media.

For their study, which was recently published in the journal Pharmaceutical Research, MU scientist Kattesh Katti, professor of radiology and physics in the School of Medicine and the College of Arts and Science, senior research scientist at the University of Missouri Research Reactor and director of the Cancer Nanotechnology Platform, and his research team combined gold salts with cinnamon and stirred the mixture in water to synthesize gold nanoparticles. This new method not only makes use of no poisonous materials, but it doesn't need any electricity, either.

While conducting their research, the scientists discovered that natural phytochemicals in cinnamon are released when the nanoparticles are created -- and these phytochemicals combined with gold nanoparticles form a promising treatment for cancer. That is because the phytochemicals are carried by the gold nanoparticles in to cancer cells and assist in the destruction or imaging of malignancies.

"From our work in green nanotechnology, it is clear that cinnamon -- and other species such as herbs, leaves and seeds -- will serve as a reservoir of phytochemicals and has the capability to convert metals in to nanoparticles," Dr. Katti said in a statement to the media. "Therefore, our approach to 'green' nanotechnology creates a renaissance symbolizing the indispensable role of Father Nature in all future nanotechnological developments."

Dr. Katti, who is the editor of The International Journal of Green Nanotechnology, added that as more makes use of for nanotechnology are created, it is crucial that scientists find ways to establish a workable connection between nanotechnology and green science.

"Nano-Foods" will be soon near your house

noreply@blogger.com (Unknown) — Sat, 11 Jun 2011 01:44:00 -0700

Imagine that your going someday to buy for Nanofoods

most of this research is going on in secret because of fears over how the public will reply. Like genetically-modified organisms (GMs), nano-modifying food involves literally changing its molecular properties, which has never been proven safe. So naturally, consumers are likely to reject NM food if given the choice.

The scientific community has an five times again caught food-tampering fever. Recent reports indicate that food scientists are busy developing nanoparticle-modified (NM) food that could day finish up on your dinner plate -- and you may never even know it. By shifting around nanoparticles, food scientists say that fat-free foods can taste likes full-fat foods, and they can be programmed to digest more slowly--two changes that some say may help reverse the obesity epidemic.

"These particles could be hazardous and they must know more about their effects both in the body and in the environment," said Frans Kampers, coordinator of research on food nanotechnology at Wageningen and Research Middle in the Netherlands. "Since these particles are small, they canâ ¦enter cells or even the nucleus of a cell if they have the right characteristics."

The said objective of nanotechnology research in food is to generate foods that behave differently than actual ones in terms of digestion, assimilation, taste and nutritional value. By altering the "nano-structure" of food, so to speak, NM food can be programmed to make people feel fuller faster, for example. And nutrients in food may even be nano-encapsulated to release at timed intervals to specific parts of the body.

Although NM food has yet to see the light day, the European Union (EU) is already taking proactive steps to make positive that, if it does make it to consumers, NM food will at least be regulated and labelled. Thus, the EU has developed a research project called NanoLyse to address the "very limited knowledge [that is] available on the potential impact of engineered nanoparticles on consumers' health."