GTRI researchers examine analytics data from their new Titan malware intelligence system. Shown are research scientists Andrew Howard and Christopher Smoak, and graduate research assistant George Macon. (Click image for high-resolution version. Credit: Gary Meek).

Known as Titan, the system will be at the center of a security community that will help create safety in numbers as companies large and small add their threat data to a knowledge base that will be shared with all participants. Operated by security specialists at the Georgia Tech Research Institute (GTRI), the system builds on a threat analysis foundation – including a malware repository that analyzes and classifies an average of 100,000 pieces of malicious code each day.

“As a university, Georgia Tech is uniquely positioned to take this white hat role in between industry and government,” said Andrew Howard, a GTRI research scientist who is part of the Titan project. “We want to bring communities together to break down the walls between industry and government to provide a trusted, sharing platform.”

Members contributing information will do so anonymously so other members won’t know which specific organizations have been attacked. GTRI will independently verify information provided to Titan and carefully vet the members of the community before they are allowed to participate.

“People tend to think that if an organization gets hit, it was because they had poor security measures,” said Christopher Smoak, a GTRI research scientist who heads up the Titan project. “That’s not necessarily true, because a variety of factors contribute to intrusions. But until we get to the point that there’s no longer a stigma attached to having an infiltration, people are going to want anonymity to participate.”

In addition to receiving information about attacks and responses at other organizations, members will receive quick reports on malware samples they submit. Based on what they have learned from the malware repository and by reverse-engineering malicious code, GTRI researchers will be able to provide information on the potential harm from an attack, the likely source, the best remedy for it and the risks to the organization.

GTRI researchers examine analytics data from their new Titan malware intelligence system. Shown are research scientists Andrew Howard and Christopher Smoak, and graduate research assistant George Macon. (Click image for high-resolution version. Credit: Gary Meek).

“We hope to provide information about the trends that organizations can expect to see, and help them prioritize what they should do to address the risks,” said Howard. “We have a significant system behind the scenes to facilitate the exchange of information.”

Titan will be especially valuable to smaller organizations that lack the resources to operate their own security evaluation labs, though all members will benefit from sharing information. GTRI information security researchers collaborate with the Georgia Tech Information Security Center (GTISC), which expands the depth of knowledge.

“GTRI will maintain the shared resources that companies can use to help solve their own problems,” Smoak noted. “We’ll have many organizations contributing to this community, and everyone getting information out; it will really benefit everyone.”

Companies today have two primary concerns about malicious software, Howard said. The first is for the loss of intellectual property, such as plans for a new product or bidding documents for a major project. The second is a compromise of the web infrastructure that many companies rely on to do business.

Titan will also help companies educate their computer users about such risks as spear-phishing, which uses email that appears to be from a trusted colleague or friend to trick users into taking a risky action, such a opening an infected attachment. The system will alert companies to the newest threat trends so they can warn their users, and identify the IP addresses that malicious software is communicating with.

“Spear-phishing is very difficult to defend against, because all it takes is one person clicking on something that lets malware into the network,” Smoak said. “It’s difficult to train a large workforce with varying skill sets to identify the very small nuances that indicate these emails are malicious.”

GTRI has been analyzing the malware attacking Windows-based computers for years. Now the analysts are seeing an increase in malicious code designed for Android-based devices – and for Macintosh computers, which previously hadn’t been high-priority targets.

“We see Android malware in its infancy right now,” said Smoak. “We see what it is doing and how it is working, and we can draw parallels to what we saw earlier with the Windows-based malware. We can probably expect to see the Android and Mac malware follow a similar path.”

The danger may be especially great for the users of computer systems that previously had not worried much about malware.

GTRI researchers examine analytics data from their new Titan malware intelligence system. Shown are research scientists Andrew Howard and Christopher Smoak, and graduate research assistant George Macon. (Click image for high-resolution version. Credit: Gary Meek).

“For Macintosh systems, the threats are starting to get scarier,” Howard said. “When more malware authors shift their focus to this platform, a lot of people who thought they were safe by not using the Windows OS will be caught off-guard.”

Titan now includes half a dozen Fortune 500 members, along with other government and nonprofit organizations. Smoak and Howard have been getting feedback from those members as they’ve built the system, which will be formally launched in a few months.

“We are looking for additional industry partners to help us use the tool and help refine the system,” said Howard. “We believe that members of this community will come together to help each other strengthen defenses.”

A determined hacker will probably succeed in compromising most corporate computer networks, but the researchers believe Titan can help companies make that as difficult as possible.

“You may not be able to completely prevent an attack, but you can have a higher wall and stronger defense,” Howard said. “Hackers tend to go after the low-hanging fruit, so they will attack the companies that are the easiest to attack. We believe that our community can help all the members strengthen their defenses.”

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Georgia Tech researchers pose with a model of graphene oxide’s structure behind them. Shown are (l-r) Elisa Riedo, Angelo Bongiorno and Claire Berger. (Click image for high-resolution version. Credit: Gary Meek)

The study also found that after the material is produced, its structural and chemical properties continue to evolve for more than a month as a result of continuing chemical reactions with hydrogen.

Understanding the properties of graphene oxide – and how to control them – is important to realizing potential applications for the material. To make it useful for nano-electronics, for instance, researchers must induce both an electronic band gap and structural order in the material. Controlling the amount of hydrogen in graphene oxide may be the key to manipulating the material properties.

“Graphene oxide is a very interesting material because its mechanical, optical and electronic properties can be controlled using thermal or chemical treatments to alter its structure,” said Elisa Riedo, an associate professor in the School of Physics at the Georgia Institute of Technology. “But before we can get the properties we want, we need to understand the factors that control the material’s structure. This study provides information about the role of hydrogen in the reduction of graphene oxide at room temperature.”

Georgia Tech researchers Angelo Bongiorno and Elisa Riedo pose with a graphene oxide sample, with a model of the material’s structure shown behind them. (Click image for high-resolution version. Credit: Gary Meek)

The research, which studied graphene oxide produced from epitaxial graphene, was reported on May 6 in the journal Nature Materials. The research was sponsored by the National Science Foundation, the Materials Research Science and Engineering Center (MRSEC) at Georgia Tech, and by the U.S. Department of Energy.

Graphene oxide is formed through the use of chemical and thermal processes that mainly add two oxygen-containing functional groups to the lattice of carbon atoms that make up graphene: epoxide and hydroxyl species. The Georgia Tech researchers began their studies with multilayer expitaxial graphene grown atop a silicon carbide wafer, a technique pioneered by Walt de Heer and his research group at Georgia Tech. Their samples included an average of ten layers of graphene.

After oxidizing the thin films of graphene using the established Hummers method, the researchers examined their samples using X-ray photo-emission spectroscopy (XPS). Over about 35 days, they noticed the number of epoxide functional groups declining while the number of hydroxyl groups increased slightly. After about three months, the ratio of the two groups finally reached equilibrium.

“We found that the material changed by itself at room temperature without any external stimulation,” said Suenne Kim, a postdoctoral fellow in Riedo’s laboratory. “The degree to which it was unstable at room temperature was surprising.”

Curious about what might be causing the changes, Riedo and Kim took their measurements to Angelo Bongiorno, an assistant professor who studies computational materials chemistry in Georgia Tech’s School of Chemistry and Biochemistry. Bongiorno and graduate student Si Zhou studied the changes using density functional theory, which suggested that hydrogen could be combining with oxygen in the functional groups to form water. That would favor a reduction in the epoxide groups, which is what Riedo and Kim were seeing experimentally.

Image shows a sample of graphene oxide produced by the oxidation of epitaxial graphene on silicon carbide. (Click image for high-resolution version. Credit: Gary Meek)

“Elisa’s group was doing experimental measurements, while we were doing theoretical calculations,” Bongiorno said. “We combined our information to come up with the idea that maybe there was hydrogen involved.”

The suspicions were confirmed experimentally, both by the Georgia Tech group and by a research team at the University of Texas at Dallas. This information about the role of hydrogen in determining the structure of graphene oxide suggests a new way to control its properties, Bongiorno noted.

“During synthesis of the material, we could potentially use this as a tool to change the structure,” he said. “By understanding how to use hydrogen, we could add it or take it out, allowing us to adjust the relative distribution and concentration of the epoxide and hydroxyl species which control the properties of the material.”

Riedo and Bongiorno acknowledge that their material – based on epitaxial graphene – may be different from the oxide produced from exfoliated graphene. Producing graphene oxide from flakes of the material involves additional processing, including dissolving in an aqueous solution and then filtering and depositing the material onto a substrate.

Georgia Tech researchers pose with a computer model of graphene oxide’s structure and the chemical species that become part of it. Shown are (l-r, first row) Elisa Riedo and Suenne Kim, (l-r, second row) Angelo Bongiorno, Claire Berger and Si Zhou. (Click image for high-resolution version. Credit: Gary Meek)

But they believe hydrogen plays a similar role in determining the properties of exfoliated graphene oxide.

“We probably have a new new form of graphene oxide, one that may be more useful commercially, although the same processes should also be happening within the other form of graphene oxide,” said Bongiorno.

The next steps are to understand how to control the amount of hydrogen in epitaxial graphene oxide, and what conditions may be necessary to affect reactions with the two functional groups. Ultimately, that may provide a way to open an electronic band gap and simultaneously obtain a graphene-based material with electron transport characteristics comparable to those of pristine graphene.

“By controlling the properties of graphene oxide through this chemical and thermal reduction, we may arrive at a material that remains close enough to graphene in structure to maintain the order necessary for the excellent electronic properties, while having the band gap needed to create transistors,” Riedo said. “It could be that graphene oxide is the way to arrive at that type of material.”

Beyond those already mentioned, the paper’s authors included Yike Hu, Claire Berger and Walt de Heer from the School of Physics at Georgia Tech, and Muge Acik and Yves Chabal from the Department of Materials Science and Engineering at the University of Texas at Dallas.

This research was supported by the National Science Foundation under grants CMMI-1100290, DMR-0820382 and DMR-0706031, and by the U.S. Department of Energy’s Office of Basic Energy Sciences under grants DE-FG02-06ER46293 and DE-SC001951. The content is solely the responsibility of the principal investigators and does not necessarily represent the official views of the National Science Foundation or the Department of Energy.

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Writer: John Toon

Suman Das, a professor in Georgia Tech’s School of Mechanical Engineering, displays a ceramic mold produced directly from digital designs using large area maskless photopolymerization (LAMP) technology. In his right hand, he holds a single-crystal superalloy turbine airfoil that was cast using a ceramic mold of the kind he holds in his left hand. (Click image for high-resolution version. Credit: Gary Meek)

Suman Das, a professor in the George W. Woodruff School of Mechanical Engineering, has developed an all-digital approach that allows a part to be made directly from its computer-aided design (CAD). The project, sponsored by the Defense Advanced Research Projects Agency (DARPA), has received $4.65 million in funding.

“We have developed a proof-of-concept system which is already turning out complex metal parts, and which fundamentally transforms the way that very high-value castings are made,” said Das, who directs the Direct Digital Manufacturing Laboratory in Georgia Tech’s Manufacturing Research Center (MaRC). “We’re confident that our approach can lower costs by at least 25 percent and reduce the number of unusable waste parts by more than 90 percent, while eliminating 100 percent of the tooling.”

The approach being utilized by Das and his team focuses on a technique called investment casting, also known as lost-wax casting. In this process, which dates back thousands of years, molten metal is poured into an expendable ceramic mold to form a part.

The mold is made by creating a wax replica of the part to be cast, surrounding or “investing” the replica with a ceramic slurry, and then drying the slurry and hardening it to form the mold. The wax is then melted out – or lost – to form a mold cavity into which metal can be poured and solidified to produce the casting.

Image shows a collection of molds made through the large area maskless photopolymerization (LAMP) technology and airfoil components produced using them. (Click image for high-resolution version. Credit: Gary Meek)

Investment casting is used to create precision parts across diverse industries including aerospace, energy, biomedical and electronics. Das’s current efforts are focused on parts used in aircraft engines. He is working with turbine-engine airfoils – complex parts used in jet engines – in collaboration with the University of Michigan and PCC Airfoils.

Today, Das explained, most precision metal castings are designed on computers, using computer-aided design software. But the next step – creating the ceramic mold with which the part is cast – currently involves a sequence of six major operations requiring expensive precision-machined dies and hundreds of tooling pieces.

“The result is a costly process that typically produces many defective molds and waste parts before a useable prototype is achieved,” Das said. “This trial-and-error development phase often requires many months to cast a part that is accurate enough to enter the next stage, which involves testing and evaluation.”

By contrast, Das’s approach involves a device that builds ceramic molds directly from a CAD design, completing the task much faster and producing far fewer unusable parts.  Called Large Area Maskless Photopolymerization (LAMP), this high-resolution digital process accretes the mold layer by layer by projecting bitmaps of ultraviolet light onto a mixture of photosensitive resin and ceramic particles, and then selectively curing the mixture to a solid.

The technique places one 100-micron layer on top of another until the structure is complete. After the mold is formed, the cured resin is removed through binder burnout and the remaining ceramic is sintered in a furnace. The result is a fully ceramic structure into which molten metal – such as nickel-based superalloys or titanium-based alloys – are poured, producing a highly accurate casting.

“The LAMP process lowers the time required to turn a CAD design into a test-worthy part from a year to about a week,” Das said. “We eliminate the scrap and the tooling, and each digitally manufactured mold is identical to the others.”

A prototype LAMP alpha machine is currently building six typical turbine-engine airfoil molds in six hours. Das predicts that a larger beta machine – currently being built at Georgia Tech and scheduled for installation at a PCC Airfoils facility in Ohio in 2012 – will produce 100 molds at a time in about 24 hours.

Although the current work focuses on turbine-engine airfoils, Das believes the LAMP technique will be effective in the production of many types of intricate metal parts. He envisions a scenario in which companies could send out part designs to digital foundries and receive test castings within a short time, much as integrated-circuit designers send CAD plans to chip foundries today.

Moreover, he said, direct digital manufacturing enabled by LAMP should allow designers to create increasingly sophisticated pieces capable of achieving greater efficiency in jet engines and other systems.

“This process can produce parts of a complexity that designers could only dream of before,” he said. “The digital technique takes advantage of high-resolution optics and precision motion systems to achieve extremely sharp, small features – on the order of 100 microns.”

Das also noted that the new process not only creates testable prototypes but could also be used in the actual manufacturing process. That would allow more rapid production of complex metal parts, in both low and high volumes, at lower costs in a variety of industries.

“When you can produce desired volumes in a short period without tooling,” he said, “you have gone beyond rapid prototyping to true rapid manufacturing.”

The project depicted in this article is sponsored by the Defense Advanced Research Projects Agency; the content of this article does not necessarily reflect the position or the policy of the government, and no official endorsement should be inferred.

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Writer: Rick Robinson

Wayne Daley, a Georgia Tech Research Institute (GTRI) principal research scientist, and Casey Ritz, a University of Georgia associate professor of poultry science, prepare to record vocalizations of a small flock of chickens at the University of Georgia’s Poultry Research Center. (Click image for high-resolution version. Credit: Gary Meek)

Researchers now believe that such avian expressiveness may be more than idle chatter. A collaborative project being conducted by the Georgia Institute of Technology and the University of Georgia is investigating whether the birds’ volubility can provide clues to how healthy and comfortable they are.

And that could be valuable information. Economically, chickens rule the roost in Georgia, where poultry is the top agricultural product with an estimated annual impact of nearly $20 billion statewide. There is industry concern about the welfare of the animals they raise; anything that helps growers reap a maximum return on every flock – while maintaining an environment conducive to their well-being – can translate to important dividends for the state’s economy.

• Watch a video on this project (YouTube).

“Many poultry professionals swear they can walk into a grow-out house and tell whether a flock is happy or stressed just by listening to the birds vocalize,” said Wayne Daley, a Georgia Tech Research Institute (GTRI) principal research scientist who is leading the research. “The trouble is, it has proved hard for these pros to pinpoint for us exactly what it is that they’re hearing.”

Researcher David Anderson in Georgia Tech’s School of Electrical and Computer Engineering analyzes chicken vocalizations digitally for clues that may help engineers and poultry scientists better control environmental conditions for the birds. (Click image for high-resolution version. Credit: Gary Meek)

Nevertheless, scientists are convinced that poultry farmers are detecting something real. Recent research at the University of Connecticut’s Department of Animal Science indicates that it is indeed possible to differentiate how the birds react to various conditions based on their vocalizations.

“The behavior of chickens is one of the best and most immediate indicators of their well-being,” said Bruce Webster, a University of Georgia poultry science professor who is working on the project. “Chickens are vocal creatures and produce different types of vocalizations at different rates and loudness depending on their circumstances.”

So the Georgia Tech/University of Georgia team is working to identify and extract specific vocalization features that will bear out both the anecdotal observations and the previous scientific work. The researchers are performing stress-related experiments on small flocks, recording the birds’ reactions on audio and video and analyzing the results.

GTRI is providing expertise in control-systems development and image processing, while Georgia Tech’s School of Electrical and Computer Engineering is contributing audio signal-processing technology and the University of Georgia is providing research facilities as well as guidance in experimental design as they relate to animal behavior and welfare issues.

Researchers from the Georgia Institute of Technology and the University of Georgia examine recordings of bird vocalizations from a small flock of chickens at the University of Georgia’s Poultry Research Center. Shown are (l-r) Wayne Daley, Bruce Webster, Doug Britton, David Anderson and Casey Ritz. (Click image for high-resolution version. Credit: Gary Meek)

“If what experienced farmers hear and sense can be defined and quantified, sensors to detect cues from the birds themselves could really make a difference in providing real-time information on house environment, bird health, and comfort,” said Michael Lacy, head of the Department of Poultry Science at the University of Georgia.

The work is funded by the Agricultural Technology Research Program, a state-supported effort to benefit the poultry and food-processing industries.

Naturally, said Daley, the poultry industry already has well-established guidelines covering optimal temperature, air quality and stocking density.  Nevertheless, costly problems can still crop up – control systems can malfunction, or presumably ideal levels can turn out to be problematic.

“That’s where being able to judge the flock’s behavior can be so important,” Daley said. “Your temperature sensors might say that things are fine, but the birds could be telling you that they think it’s a bit too warm or other changes have occurred to make the conditions less than ideal.”

From a poultry professional’s viewpoint, the flock’s opinion is probably the definitive one. Chickens take only six weeks to go from hatching to finished weight; stressful conditions can retard their growth, reducing their value when they go to market.

Wayne Daley, a Georgia Tech Research Institute (GTRI) principal research scientist, and Casey Ritz, a University of Georgia associate professor of poultry science, prepare to record vocalizations of a small flock of chickens at the University of Georgia’s Poultry Research Center. (Click image for high-resolution version. Credit: Gary Meek)

“Contract poultry producers are paid by the pound of birds sent to market. Improving the overall health and productivity of the birds will help to improve the bottom line for individual producers,” said Casey Ritz, a University of Georgia associate professor of poultry science who is involved in the research.

The research team has conducted several experiments in which they have exposed flocks to mildly stressful environmental changes.  For example, temperature or ammonia levels might be increased from their initial settings for a few hours, then returned to the original level.

The researchers have recorded the flocks’ vocal reactions to the experiments, with video also collected in many instances.  To date, more than four terabytes of bird-vocalization audio has been gathered.

Almost at once, the researchers encountered a knotty problem as they recorded bird sounds. They discovered that the large fans necessary for air circulation in a grow-out house can be considerably louder than the chickens, making it difficult to capture bird vocalizations effectively.

David Anderson, a professor in the Georgia Tech School of Electrical and Computer Engineering, has been working on the best methods for harvesting useable bird sounds from the noisy environment.  It’s a classic audio signal-processing problem, he said, in which the signal of interest must separated from the noise that surrounds it.

A small flock of chickens is shown at the University of Georgia’s Poultry Research Center. Poultry scientists from the University of Georgia are working with digital signal processing specialists and food processing experts from Georgia Tech in an effort to assess the condition of flocks from their collective vocalizations. (Click image for high-resolution version. Credit: Gary Meek)

“We have several approaches for extracting poultry voicing from the others noises, and we’ve been pretty successful in achieving that,” he said.  “What makes this different from most other bird-song research is that we’re not listening to individuals, we’re listening to sounds in the aggregate. It’s like trying to understand what people are saying in a restaurant, when all you hear are the murmurings of a hundred diners.”

To decode mass poultry vocalizing, Anderson is extracting particular features of the sound, such as speed, volume, pitch and other qualities. Then he’s utilizing machine learning – in which computers recognize complex patterns in data and make decisions based on those patterns – to analyze the extracted features and determine which characteristics may convey specific meanings.

“These are initial experiments, and we’re going to have to test under a variety of conditions, but we’ve had considerable success already,” Anderson said.  “By listening to the flock we can accurately tell when the birds are experiencing particular kinds of stress, such as significant temperature changes.”

In addition to ensuring high yield flocks, bird-vocalization analysis could save poultry growers money in equipment costs as well, Anderson suggested.  For instance, he said, currently available ammonia sensors are both expensive and short-lived.  If a system consisting of a few microphones and the right computer algorithms could take over ammonia-detection tasks, it would help reduce costs for the entire industry.

To date, video of the flocks hasn’t produced results as useful as the sound recordings, said GTRI’s Daley. But image processing of flock-reaction video continues, and could yield significant data down the road.

“This multi-disciplinary, multi-institution project highlights the different skills necessary to tackle current problems,” Daley said.  “This approach will be valuable in years to come as we tackle a variety of problems to help the industry continue to be profitable and sustainable.”

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Writer: Rick Robinson

Tristan Al-Haddad, left, assistant professor in the Georgia Tech College of Architecture, and College of Architecture research scientist Karl Brohammer, examine architectural cladding prototypes that have been digitally fabricated using ultra-high-performance concrete. (Click image for high-resolution version. Credit: Gary Meek)

Researchers in the College of Architecture at the Georgia Institute of Technology are now automating some of the processes by which computer-based designs are turned into real world entities. They’re developing techniques that fabricate building elements directly from digital designs, allowing custom concrete components to be manufactured rapidly and at low cost.

“We’re developing the research and the protocols to manufacture high-end customized architectural products economically, safely and with environmental responsibility,” said Tristan Al-Haddad, an assistant professor in the College of Architecture who is a leader in this effort. “We think this work offers opportunities for architectural creativity at a new level and with tremendously increased efficiency.”

• In one recent project, Al-Haddad and a College of Architecture team collaborated with Lafarge North America to fabricate an award-winning building-element concept called a “Liquid Wall.” The Georgia Tech team employed digital techniques to help construct a prototype wall, using ultra high-performance concrete; the result was displayed by the New York Chapter of the American Institute of Architects (AIANY) in the “Innovate:Integrate” exhibition.
• In another Lafarge-sponsored project, Al-Haddad and a College of Architecture team are developing a complete free-standing structure using ultra high-performance concrete elements fabricated directly from digital designs.

Computing a Wall

The Liquid Wall, originated by Peter Arbour of Paris-based RFR Consulting Engineers, won the 2010 Open Call for Innovative Curtain-Wall Design competition conducted by the AIA. The concept advanced a novel approach to curtain walls, which are building coverings that keep out weather but are non-structural and lightweight.

Researchers in Georgia Tech’s College of Architecture are helping automate the process of turning CAD designs into manufactured products. Here, professor Tristan Al-Haddad and undergraduate students Sam Kim and Patrick di Rito are evaluating custom wall structures manufactured using a new process. (Click image for high-resolution version. Credit: Gary Meek).

RFR’s plans called for the Liquid Wall to be constructed of stainless steel and Ductal®, a light and strong ultra-high-performance concrete (UHPC) that is produced by Lafarge. Moreover, the new building enclosure was conceived as an entire system, including integrated louver systems, solar shading, integrated passive solar collectors and other advanced features.

Georgia Tech became involved in the Liquid Wall project when RFR decided to built a full-scale prototype of the complex concept. RFR asked Al-Haddad to help turn Arbour’s original parametric sketches into a manufacturable design.

Supported by the College of Architecture’s Digital Building and Digital Fabrication laboratories, the researchers refined the geometry of the original sketches for manufacturability and developed the techniques required for fabricating a full-size curtain wall. Then, working from their digital models and using a five-axis CNC router – a device capable of machining material directly from a digital design – the Georgia Tech team milled a full-scale model of the wall. The model was made from a lightweight polymer material, expanded polystyrene (EPS) closed-cell foam, which was then given a polyurea coating.

The digitally milled foam model created an exact replica — a positive — of the final wall.  The lightweight positive could then be used to produce a negative capable of forming the actual prototype. In this case, the collaborators used the positive to produce a rubber mold – the negative – from which the final wall was cast.

The foam positive was shipped to Coreslab Structures Inc., a large corporation that specializes in industrial-scale casting. The Georgia Tech team then worked with Coreslab to identify the best techniques for creating the rubber mold and for pouring in Ductal to form the concrete wall.

“It was a very collaborative process – the four major players were Peter Arbour and RFR, Georgia Tech, Coreslab and Lafarge,” Al-Haddad said. “And we had all of three weeks to finish the work before the exhibition deadline – so it was pretty intense.”

Other College of Architecture people involved in the collaboration included graduate student Andres Cavieres, associate professor Russell Gentry and professor Charles Eastman, director of the Digital Building Laboratory. The resulting full-size Liquid Wall prototype was installed at the Center for Architecture in New York City as part of the AIANY’s “Innovate: Integrate” exhibition, and was on view for several months in 2010 and 2011.

Confronting Challenges

The Liquid Wall project was challenging, said Eastman, who holds joint appointments in the College of Architecture and the College of Computing. The process involved not only producing rubber negatives using wall-form designs created with CAD and parametric-modeling software, but also required identifying the right production procedures and finding effective ways of installing a completed full-size wall on a building.

“When you’re creating a completely new process like the Liquid Wall, you’re faced with developing a whole new manufacturing process for this kind of material,” Eastman said.

A future project, expected to be about 20 by 20 feet square and 15 feet high, will be built using Ductal UHPC, principally or entirely. A central technical challenge will involve molding the many custom elements so that all edges fit together and form a structure that is stable, practical and esthetically pleasing.

“We understand the structural side of a project like this quite well — the difficulty comes in the actual manufacturing of the elements,” Al-Haddad said. “We want to advance the use of digital parametric models with custom molding systems, and create a free-form manufacturing system that can produce many variations quickly and accurately.”

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Writer: Rick Robinson

Hematoxylin and eosin (H&E) staining of sections of wild-type (top row) and H1 triple-knockout (bottom row) embryoid bodies. After 14 days in rotary suspension culture, the wild-type embryoid bodies showed more differentiated morphologies with cysts forming (black arrows) and the knockout embryoid bodies failed to form cavities (far right). (Click image for high-resolution version. Credit: Yuhong Fan)

Researchers from the Georgia Institute of Technology and Emory University found that chromatin compaction is required for proper embryonic stem cell differentiation to occur. Chromatin, which is composed of histone proteins and DNA, packages DNA into a smaller volume so that it fits inside a cell.

A study published on May 10, 2012 in the journal PLoS Genetics found that embryonic stem cells lacking several histone H1 subtypes and exhibiting reduced chromatin compaction suffered from impaired differentiation under multiple scenarios and demonstrated inefficiency in silencing genes that must be suppressed to induce differentiation.

“While researchers have observed that embryonic stem cells exhibit a relaxed, open chromatin structure and differentiated cells exhibit a compact chromatin structure, our study is the first to show that this compaction is not a mere consequence of the differentiation process but is instead a necessity for differentiation to proceed normally,” said Yuhong Fan, an assistant professor in the Georgia Tech School of Biology.

Fan and Todd McDevitt, an associate professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, led the study with assistance from Georgia Tech graduate students Yunzhe Zhang and Kaixiang Cao, research technician Marissa Cooke, and postdoctoral fellow Shiraj Panjwani.

The work was supported by the National Institutes of Health’s National Institute of General Medical Sciences (NIGMS), the National Science Foundation, a Georgia Cancer Coalition Distinguished Scholar Award, and a Johnson & Johnson/Georgia Tech Healthcare Innovation Award.

Phase contrast images showing that H1 triple-knockout (bottom) embryonic stem cells were unable to adequately form neurites and neural networks compared to wild-type embryonic stem cells (top). (Click image for high-resolution version. Credit: Yuhong Fan)

To investigate the impact of linker histones and chromatin folding on stem cell differentiation, the researchers used embryonic stem cells that lacked three subtypes of linker histone H1 — H1c, H1d and H1e — which is the structural protein that facilitates the folding of chromatin into a higher-order structure. They found that the expression levels of these H1 subtypes increased during embryonic stem cell differentiation, and embryonic stem cells lacking these H1s resisted spontaneous differentiation for a prolonged time, showed impairment during embryoid body differentiation and were unsuccessful in forming a high-quality network of neural cells.

“This study has uncovered a new, regulatory function for histone H1, a protein known mostly for its role as a structural component of chromosomes,” said Anthony Carter, who oversees epigenetics grants at NIGMS.  “By showing that H1 plays a part in controlling genes that direct embryonic stem cell differentiation, the study expands our understanding of H1’s function and offers valuable new insights into the cellular processes that induce stem cells to change into specific cell types.”

During spontaneous differentiation, the majority of the H1 triple-knockout embryonic stem cells studied by the researchers retained a tightly packed colony structure typical of undifferentiated cells and expressed high levels of Oct4 for a prolonged time. Oct4 is a pluripotency gene that maintains an embryonic stem cell’s ability to self-renew and must be suppressed to induce differentiation.

“H1 depletion impaired the suppression of the Oct4 and Nanog pluripotency genes, suggesting a novel mechanistic link by which H1 and chromatin compaction may mediate pluripotent stem cell differentiation by contributing to the epigenetic silencing of pluripotency genes,” explained Fan. “While a significant reduction in H1 levels does not interfere with embryonic stem cell self-renewal, it appears to impair differentiation.”

Immunostaining of wild-type (top) and H1 triple-knockout (bottom) cultures under a neural differentiation protocol. The H1 triple-knockout cells were defective in forming neuronal and glial cells and a neural network, which is essential for nervous system development. (Click image for high-resolution version. Credit: Yuhong Fan)

The researchers also used a rotary suspension culture method developed by McDevitt to produce with high efficiency homogonous 3D clumps of embryonic stem cells called embryoid bodies. Embryoid bodies typically contain cell types from all three germ layers — the ectoderm, mesoderm and endoderm — that give rise to the various types of tissues and structures in the body. However, the majority of the H1 triple-knockout embryoid bodies formed in rotary suspension culture lacked differentiated structures and displayed gene expression signatures characteristic of undifferentiated stem cells.

“H1 triple-knockout embryoid bodies displayed a reduced level of activation of many developmental genes and markers in rotary culture, suggesting that differentiation to all three germ layers was affected.” noted McDevitt.

The embryoid bodies also lacked the epigentic changes at the pluripotency genes necessary for differentiation, according to Fan.

“When we added one of the deleted H1 subtypes to the embryoid bodies, Oct4 was suppressed normally and embryoid body differentiation continued,” explained Fan. “The epigenetic regulation of Oct4 expression by H1 was also evident in mouse embryos.”

In another experiment, the researchers provided an environment that would encourage embryonic stem cells to differentiate into neural cells. However, the H1 triple-knockout cells were defective in forming neuronal and glial cells and a neural network, which is essential for nervous system development. Only 10 percent of the H1 triple-knockout embryoid bodies formed neurites and they produced on average eight neurites each. In contrast, half of the normal embryoid bodies produced, on average, 18 neurites.

In future work, the researchers plan to investigate whether controlling H1 histone levels can be used to influence the reprogramming of adult cells to obtain induced pluripotent stem cells, which are capable of differentiating into tissues in a way similar to embryonic stem cells.

Research reported in this publication was supported by the National Institute of General Medical Sciences of the National Institutes of Health (NIH) under award number GM085261 and the National Science Foundation under award number CBET-0939511. The content is solely the responsibility of the principal investigators and does not necessarily represent the official views of the NIH or NSF.

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Jonathan Colton, a professor in the George W. Woodruff School of Mechanical Engineering and the School of Industrial Design at Georgia Tech, will pursue an innovative global health and development research project focused on designing a net-zero energy warehousing and distribution system for vaccines and drugs in developing countries. Net-zero energy describes a building with no net energy consumption and no carbon emissions measured on an annual basis.

Jonathan Colton, a professor in the School of Mechanical Engineering and the School of Industrial Design at Georgia Tech, received a $100,000 Grand Challenges Explorations grant from the Bill & Melinda Gates Foundation to design a net-zero energy warehousing and distribution system for vaccines and drugs in developing countries. (Click image for high-resolution version. Credit: USAID/PATH/Gabe Bienczycki)

In addition to Colton, immunization logistics consultant John Lloyd, architect Andrew Garnett and Solar Electric Light Fund project manager Steve McCarney will also contribute to the project.

The project was one of more than 100 Grand Challenges Explorations grants announced May 9, 2012.

“Grand Challenges Explorations encourages individuals worldwide to expand the pipeline of ideas where creative, unorthodox thinking is most urgently needed,” said Chris Wilson, director of Global Health Discovery and Translational Sciences at the Bill & Melinda Gates Foundation.  “We’re excited to provide additional funding for select grantees so that they can continue to advance their idea towards global impact.”

The goal of the Georgia Tech project is to develop the design and engineering specifications for a new, energy-optimized warehousing and distribution system for vaccines and drugs. In low- and middle-income countries, vaccines and drugs are often stored in older buildings that are inefficiently laid out and wasteful of energy. In these countries, warehousing and distribution costs can amount to 20 percent of drug and vaccine supply costs.

“We plan to demonstrate that energy-efficient, state-of-the-art warehousing systems can eliminate or greatly reduce the operational energy costs for storage and distribution of vaccines and drugs in developing countries with challenging climates,” said Colton.

According to Colton, to be successful the new warehousing system will need to:

• Minimize environmental impact, energy consumption, and storage and transport costs;
• Offset any grid electricity consumption;
• Employ low-energy cooling techniques;
• Accommodate a variety of building sizes and configurations; and
• Be able to store vaccines, drugs and dry supplies at various controlled temperatures.

“Once we create the design and engineering specifications for this new warehousing and storage system, we plan to select an industry partner to build and test the system in a developing country such as Tunisia,” added Colton.

About Grand Challenges Explorations: Grand Challenges Explorations is a $100 million initiative funded by the Bill & Melinda Gates Foundation. Launched in 2008, more than 600 people in 45 countries have received Grand Challenges Explorations grants. The grant program is open to anyone from any discipline and from any organization. The initiative uses an agile, accelerated grant-making process with short two-page online applications and no preliminary data required. Initial grants of $100,000 are awarded two times a year. Successful projects have the opportunity to receive a follow-on grant of up to $1 million.

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Researchers at MIT and Georgia Tech have developed a way to automate a process called whole-cell patch clamping, which involves bringing a tiny hollow glass pipette in contact with the cell membrane of a neuron, then opening up a small pore in the membrane to record the electrical activity within the cell. (Click image for high-resolution version. Credit: Sputnik Animation and MIT McGovern Institute)

But that could soon change: Researchers at MIT and the Georgia Institute of Technology have developed a way to automate the process of finding and recording information from neurons in the living brain. The researchers have shown that a robotic arm guided by a cell-detecting computer algorithm can identify and record from neurons in the living mouse brain with better accuracy and speed than a human experimenter.

The new automated process eliminates the need for months of training and provides long-sought information about living cells’ activities. Using this technique, scientists could classify the thousands of different types of cells in the brain, map how they connect to each other, and figure out how diseased cells differ from normal cells.

The project is a collaboration between the labs of Ed Boyden, associate professor of biological engineering and brain and cognitive sciences at MIT, and Craig Forest, an assistant professor in the George W. Woodruff School of Mechanical Engineering at Georgia Tech.

“Our team has been interdisciplinary from the beginning, and this has enabled us to bring the principles of precision machine design to bear upon the study of the living brain,” Forest says. His graduate student, Suhasa Kodandaramaiah, spent the past two years as a visiting student at MIT, and is the lead author of the study, which appears in the May 6 issue of Nature Methods.

The method could be particularly useful in studying brain disorders such as schizophrenia, Parkinson’s disease, autism and epilepsy, Boyden says. “In all these cases, a molecular description of a cell that is integrated with [its] electrical and circuit properties … has remained elusive,” says Boyden, who is a member of MIT’s Media Lab and McGovern Institute for Brain Research. “If we could really describe how diseases change molecules in specific cells within the living brain, it might enable better drug targets to be found.”

Automation

Kodandaramaiah, Boyden and Forest set out to automate a 30-year-old technique known as whole-cell patch clamping, which involves bringing a tiny hollow glass pipette in contact with the cell membrane of a neuron, then opening up a small pore in the membrane to record the electrical activity within the cell. This skill usually takes a graduate student or postdoc several months to learn.

MIT and Georgia Tech researchers developed a four-step process that a robotic arm guided by a cell-detecting computer algorithm uses to find and record information from neurons in the living brain. The pipette is lowered to a target zone in the brain, the pipette is advanced until a neuron is detected, a seal is formed between the pipette and the cell, and a small pore is opened in the membrane to record the electrical activity within the cell. (Click image for high-resolution version. Credit: MIT and Georgia Tech)

Kodandaramaiah spent about four months learning the manual patch-clamp technique, giving him an appreciation for its difficulty. “When I got reasonably good at it, I could sense that even though it is an art form, it can be reduced to a set of stereotyped tasks and decisions that could be executed by a robot,” he says.

To that end, Kodandaramaiah and his colleagues built a robotic arm that lowers a glass pipette into the brain of an anesthetized mouse with micrometer accuracy. As it moves, the pipette monitors a property called electrical impedance — a measure of how difficult it is for electricity to flow out of the pipette. If there are no cells around, electricity flows and impedance is low. When the tip hits a cell, electricity can’t flow as well and impedance goes up.

The pipette takes two-micrometer steps, measuring impedance 10 times per second. Once it detects a cell, it can stop instantly, preventing it from poking through the membrane. “This is something a robot can do that a human can’t,” Boyden says.

Once the pipette finds a cell, it applies suction to form a seal with the cell’s membrane. Then, the electrode can break through the membrane to record the cell’s internal electrical activity. The robotic system can detect cells with 90 percent accuracy, and establish a connection with the detected cells about 40 percent of the time.

The researchers also showed that their method can be used to determine the shape of the cell by injecting a dye; they are now working on extracting a cell’s contents to read its genetic profile.

Development of the new technology was funded primarily by the National Institutes of Health, the National Science Foundation and the MIT Media Lab.

New era for robotics

The researchers recently created a startup company, Neuromatic Devices, to commercialize the device.

MIT researcher Ed Boyden (left) and Georgia Tech researchers Suhasa Kodandaramaia (seated) and Craig Forest have developed a way to automate the process of finding and recording information from neurons in the living brain. (Click image for high-resolution version. Credit: MIT)

The researchers are now working on scaling up the number of electrodes so they can record from multiple neurons at a time, potentially allowing them to determine how different parts of the brain are connected.

They are also working with collaborators to start classifying the thousands of types of neurons found in the brain. This “parts list” for the brain would identify neurons not only by their shape — which is the most common means of classification — but also by their electrical activity and genetic profile.

“If you really want to know what a neuron is, you can look at the shape, and you can look at how it fires. Then, if you pull out the genetic information, you can really know what’s going on,” Forest says. “Now you know everything. That’s the whole picture.”

Boyden says he believes this is just the beginning of using robotics in neuroscience to study living animals. A robot like this could potentially be used to infuse drugs at targeted points in the brain, or to deliver gene therapy vectors. He hopes it will also inspire neuroscientists to pursue other kinds of robotic automation — such as in optogenetics, the use of light to perturb targeted neural circuits and determine the causal role that neurons play in brain functions.

Neuroscience is one of the few areas of biology in which robots have yet to make a big impact, Boyden says. “The genome project was done by humans and a giant set of robots that would do all the genome sequencing. In directed evolution or in synthetic biology, robots do a lot of the molecular biology,” he says. “In other parts of biology, robots are essential.”

Other co-authors include MIT grad student Giovanni Talei Franzesi and MIT postdoc Brian Y. Chow.

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Georgia Tech Research Institute researchers Brent Wagner (l) and Bernd Kahn are using novel materials and nanotechnology techniques to develop improved radiation detection. (Click image for high-resolution version. Credit: Gary Meek)

To support the nation’s nuclear-surveillance capabilities, researchers at the Georgia Tech Research Institute (GTRI) are developing ways to enhance the radiation-detection devices used at ports, border crossings, airports and elsewhere. The aim is to create technologies that will increase the effectiveness and reliability of detectors in the field, while also reducing cost. The work is co-sponsored by the Domestic Nuclear Defense Office of the Department of Homeland Security and by the National Science Foundation.

“U.S. security personnel have to be on guard against two types of nuclear attack — true nuclear bombs, and devices that seek to harm people by dispersing radioactive material,” said Bernd Kahn, a researcher who is principal investigator on the project. “Both of these threats can be successfully detected by the right technology.”

The GTRI team, led by co-principal investigator Brent Wagner, is utilizing novel materials and nanotechnology techniques to produce improved radiation detection. The researchers have developed the Nano-photonic Composite Scintillation Detector, a prototype that combines rare-earth elements and other materials at the nanoscale for improved sensitivity, accuracy and robustness.

Bernd Kahn, seated, and Brent Wagner review a pulse height spectrum collected using a scintillation radiation detector they devised. The GTRI researchers are using novel materials and nanotechnology techniques to develop improved radiation detection. (Click image for high-resolution version. Credit: Gary Meek)

Details of the research were presented April 23, 2012 at the SPIE Defense, Security, and Sensing Conference held in Baltimore, MD.

Scintillation detectors and solid-state detectors are two common types of radiation detectors, Wagner explained. A scintillation detector commonly employs a single crystal of sodium iodide or a similar material, while a solid-state detector is based on semiconducting materials such as germanium.

Both technologies are able to detect gamma rays and subatomic particles emitted by nuclear material. When gamma rays or particles strike a scintillation detector, they create light flashes that are converted to electrical pulses to help identify the radiation at hand. In a solid-state detector, incoming gamma rays or particles register directly as electrical pulses.

“Each reaction to a gamma ray takes a very short time — a fraction of a microsecond,” Wagner said. “By looking at the number and the intensity of the pulses, along with other factors, we can make informed judgments about the type of radioactive material we’re dealing with.”

But both approaches have drawbacks. A scintillation detector requires a large crystal grown from sodium iodide or other materials. Such crystals are typically fragile, cumbersome, difficult to produce and extremely vulnerable to humidity.

Examples of scintillators that were produced from molten glass by the GTRI researchers. The wormlike blue structure is an artifact from the glass-molding process. (Click image for high-resolution version. Credit: Gary Meek)

A germanium-based solid-state detector offers better identification of different kinds of nuclear materials. But high-purity single-crystal germanium is difficult to make in a large volume; the result is less-sensitive devices with reduced ability to detect radiation at a distance. Moreover, germanium must be kept extremely cold — 200 degrees below zero Celsius — to function properly, which poses problems for use in the field.

The Nanoscale Advantage

To address these problems, the GTRI team has been investigating a wide variety of alternative materials and methodologies. After selecting the scintillation approach over solid-state, the researchers developed a composite material — composed of nanoparticles of rare-earth elements, halides and oxides — capable of creating light.

“A nanopowder can be much easier to make, because you don’t have to worry about producing a single large crystal that has zero imperfections,” Wagner said.

A scintillator crystal must be transparent to light, he explained, a quality that’s key to its ability to detect radiation. A perfect crystal uniformly converts incoming energy from gamma rays to flashes of light. A photo-multiplier then amplifies these flashes of light so they can be accurately measured to provide information about radioactivity.

Georgia Tech Research Institute researchers Brent Wagner (l) and Bernd Kahn are using novel materials and nanotechnology techniques to develop improved radiation detection. (Click image for high-resolution version. Credit: Gary Meek)

However, when a transparent material — such as crystal or glass — is ground into smaller pieces, its transparency disappears. As a result, a mixture of particles in a transparent glass would scatter the luminescence created by incoming gamma rays. That scattered light can’t reach the photo-multiplier in a uniform manner, and the resulting readings are badly skewed.

To overcome this issue, the GTRI team reduced the particles to the nanoscale. When a nanopowder reaches particle sizes of 20 nanometers or less, scattering effects fade because the particles are now significantly smaller than the wavelength of incoming gamma rays.

“Think of it as a big ocean wave coming in,” Wagner said. “That wave would definitely interact with a large boat, but something the size of a beach ball doesn’t affect it.”

Rare Earths and Silica

At first the team worked on dispersing radiation-sensitive crystalline nanoparticles in a plastic matrix. But they encountered problems with distributing the nanopowder uniformly enough in the matrix to achieve sufficiently accurate radiation readings.

More recently, the researchers have investigated a parallel path using glass rather than plastic as a matrix material, combining gadolinium and cerium bromide with silica and alumina.

Kahn explained that gadolinium or a similar material is essential to scintillation-type particle detection because of its role as an absorber. But in this case, when an incoming gamma ray is absorbed in gadolinium, the energy is not efficiently emitted in the form of luminescence.

Instead, the light emission role here falls to a second component — cerium. The gadolinium absorbs energy from an incoming gamma ray and transfers that energy to the cerium atom, which then acts as an efficient light emitter.

The researchers found that by heating gadolinium, cerium, silica and alumina and then cooling them from a molten mix to a solid monolith, they could successfully distribute the gadolinium and cerium in silica-based glasses. As the material cools, gadolinium and cerium precipitate out of the aluminosilicate solution and are distributed throughout the glass in a uniform manner. The resulting composite gives dependable readings when exposed to incoming gamma rays.

“We’re optimistic that we’ve identified a productive methodology for creating a material that could be effective in the field,” Wagner said. “We’re continuing to work on issues involving purity, uniformity and scaling, with the aim of producing a material that can be successfully tested and deployed.”

This material is based upon work supported by the U.S. Department of Homeland Security under Grant Award Number 2008-DN-077-ARI001-02. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Department of Homeland Security.

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Molecular probes displaying the LNLPHG and RFSAFY peptide sequences showed the greatest binding affinity to fibronectin fibers and the greatest efficiency in discriminating between relaxed and strained fibers. On extracellular matrix assembled by primary lung fibroblasts, LNLPHG preferentially attached to relaxed fibronectin fibers (top row), whereas RFSAFY bound to strained fibers (bottom row). (Scale bar: 20 microns) (Click image for high-resolution version. Credit: Thomas Barker)

During physiological processes, fibronectin fibers are believed to experience mechanical forces that strain the fibers and cause dramatic structural modifications that change their biological activity. While understanding the role of fibronectin strain events in development and disease progression is becoming increasingly important, detecting and interrogating these events is difficult.

In a new study, researchers identified molecular probes capable of selectively attaching to fibronectin fibers under different strain states, enabling the detection and examination of fibronectin strain events in both culture and living tissues.

“The mechano-sensitive molecular probes we identified allow us to dynamically examine the relevance of mechanical strain events within the natural cellular microenvironment and correlate these events with specific alterations in fibronectin associated with the progression of disease,” said Thomas Barker, an assistant professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.

The study was published on April 23, 2012 in the online early edition of the journal Proceedings of the National Academy of Sciences. Barker worked on the study with Georgia Tech graduate student Lizhi Cao and Harry Bermudez, an assistant professor in the University of Massachusetts Amherst Department of Polymer Science and Engineering. The research was supported by the National Institutes of Health.

Researchers have hypothesized that mechanical forces emanating from cells may partially unfold fibronectin and regulate what proteins bind to it. While simulation and tissue culture experiments support this hypothesis, direct evidence that such molecular events occur in living organisms has not yet been presented, according to Barker.

A technique called intramolecular fluorescence resonance energy transfer (FRET) has been used to detect molecular strain events in fibronectin fibers, but the technique has limitations because it cannot be used on living tissues and requires the fibronectin to be chemically labeled.

“The molecular probes we identified can be used to map molecular strain events in native extracellular matrix and living lung tissues,” explained Barker. “The probes can also be used to study the mechanism by which cells control the mechanical forces that alter fibronectin’s conformation, control the exposure of its binding sites and regulate cell signaling.”

Staining of fibronectin-targeting molecular probes displaying the LNLPHG (blue) and RFSAFY (red) peptide sequences on prepared living lung slices. The probes did not attach to the same fiber, which confirmed their ability to selectively discriminate strained or relaxed regions within a fibronectin fiber network. (Click image for high-resolution version. Credit: Thomas Barker)

The researchers used a controlled fibronectin fiber deposition and extension technique to apply tension to the fibers and stretch them to 2.6 times their original length without significant breakage. Then they used a technique called phage display to identify peptides capable of discriminating fibronectin fibers under relaxed and strained conditions. The molecular probes displaying peptide sequences LNLPHG and RFSAFY showed the greatest binding affinity to fibronectin fibers and the greatest efficiency in discriminating between relaxed and strained fibers.

For proof-of-concept demonstrations, the researchers used the probes to discriminate fibronectin fibers within native extracellular matrix and mouse lung slices. LNLPHG preferentially attached to relaxed fibronectin fibers, whereas RFSAFY bound to strained fibers. The probes never attached to the same fiber, which confirmed their ability to selectively discriminate regions within a fibronectin fiber network.

“This study strongly suggests that fibronectin fibers under strain display markedly different biochemical signatures that can be used for the molecular-level detection of fibronectin fiber strain,” explained Barker. “The data also show the potential for living tissue to be interrogated for mechano-chemical alterations that lead to physiological and pathological progression.”

In the future, the researchers hope to use these fibronectin strain-sensitive probes to target therapeutics to fibronectin fibers based on their mechanical signature.

This work was supported in part by training grants from the National Institutes of Health (NIH) (Award Nos. T32-GM008433 and T32-EB006343). The content is solely the responsibility of the principal investigators and does not necessarily represent the official views of the NIH.

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