Researchers create living human gut-on-a-chip

Building on the Wyss Institute's breakthrough "Organ-on-Chip" technology that uses microfabrication techniques to build living organ mimics, the gut-on-a-chip is a silicon polymer device about the size of a computer memory stick. Wyss Founding Director, Donald Ingber, M.D., Ph.D., led the research team, which included Postdoctoral Fellow, Hyun Jung Kim, Ph.D; Technology Development Fellow, Dan Huh, Ph.D.; and Senior Staff Scientist, Geraldine Hamilton, Ph.D. Ingber is also the Judah Folkman Professor of Vascular Biology at Harvard Medical School and the Vascular Biology Program at Children's Hospital Boston, and Professor of Bioengineering at Harvard's School of Engineering and Applied Sciences.

The new device mimics complex 3D features of the intestine in a miniaturized form. Inside a central chamber, a single layer of human intestinal epithelial cells grows on a flexible, porous membrane, recreating the intestinal barrier. The membrane attaches to side walls that stretch and recoil with the aid of an attached vacuum controller. This cyclic mechanical deformation mimics the wave-like peristaltic motions that move food along the digestive tract. The design also recapitulates the intestinal tissue-tissue interface, which allows fluids to flow above and below the intestinal cell layer, mimicking the luminal microenvironment on one side of the device and the flow of blood through capillary vessels on the other.

In addition, the researchers were able to grow and sustain common intestinal microbes on the surface of the cultured intestinal cells, thereby simulating some of the physiological features important to understanding many diseases. These combined capabilities suggest that gut-on-a-chip has the potential to become a valuable in vitro diagnostic tool to better understand the cause and progression of a variety of intestinal disorders and to help develop safe and effective new therapeutics, as well as probiotics. The gut-on-a-chip could also be used to test the metabolism and oral absorption of drugs and nutrients.

"Because the models most often available to us today do not recapitulate human disease, we can't fully understand the mechanisms behind many intestinal disorders, which means that the drugs and therapies we validate in animal models often fail to be effective when tested in humans," said Ingber. "Having better, more accurate in vitro disease models, such as the gut-on-a-chip, can therefore significantly accelerate our ability to develop effective new drugs that will help people who suffer from these disorders."

Gut-on-a-chip represents the most recent advance in the Wyss Institute's portfolio of engineered organ models. The platform technology was first reported on in Science in June 2010, where a living, breathing, human lung-on-a-chip was described. That same year, the Wyss received funding from the National Institutes of Health and the U.S. Food and Drug Administration to develop a heart-lung micromachine to test the safety and efficacy of inhaled drugs on the integrated heart and lung function. In September 2011, the Wyss was awarded a four-year grant from the Defense Advanced Research Projects Agency to develop a spleen-on-a-chip to treat sepsis, a commonly fatal bloodstream infection.

Provided by Harvard University (news : web)

Researchers create more efficient hydrogen fuel cells

 Hydrogen fuel cells, like those found in some "green" vehicles, have a lot of promise as an alternative fuel source, but making them practical on a large scale requires them to be more efficient and cost effective.

A research team from the University of Central Florida may have found a way around both hurdles.

The majority of hydrogen fuel cells use catalysts made of a rare and expensive metal -- platinum. There are few alternatives because most elements can't endure the fuel cell's highly acidic solvents present in the reaction that converts hydrogen's chemical energy into electrical power. Only four elements can resist the corrosive process -- platinum, iridium, gold and palladium. The first two are rare and expensive, which makes them impractical for large-scale use. The other two don't do well with the chemical reaction.

UCF Professor Sergey Stolbov and postdoctoral research associate Marisol Alcántara Ortigoza focused on making gold and palladium better suited for the reaction.

They created a sandwich-like structure that layers cheaper and more abundant elements with gold and palladium and other elements to make it more effective.

The outer monoatomic layer (the top of the sandwich) is either palladium or gold. Below it is a layer that works to enhance the energy conversion rate but also acts to protect the catalyst from the acidic environment. These two layers reside on the bottom slice of the sandwich -- an inexpensive substrate (tungsten), which also plays a role in the stability of the catalyst.

"We are very encouraged by our first attempts that suggest that we can create two cost-effective and highly active palladium- and gold-based catalysts -for hydrogen fuel cells, a clean and renewable energy source," Stolbov said.

Stolbov's work was recently published in The Journal of Physical Chemistry Letters.

By creating these structures, more energy is converted, and because the more expensive and rare metals are not used, the cost could be significantly less.

Stolbov said experiments are needed to test their predictions, but he says the approach is quite reliable. He's already working with a group within the U.S. Department of Energy to determine whether the results can be duplicated and have potential for large-scale application.

If a way could be found to make hydrogen fuel cells practical and cost effective, vehicles that run on gasoline and contribute to the destruction of the ozone layer could become a thing of the past.

Story Source:

The above story is reprinted from materials provided by University of Central Florida.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Sergey Stolbov, Marisol Alcántara Ortigoza. Rational Design of Competitive Electrocatalysts for Hydrogen Fuel Cells. The Journal of Physical Chemistry Letters, 2012; 3 (4): 463 DOI: 10.1021/jz201551e

Researchers create more efficient hydrogen fuel cells

A research team from the University of Central Florida may have found a way around both hurdles.

The majority of hydrogen fuel cells use catalysts made of a rare and expensive metal – platinum. There are few alternatives because most elements can't endure the fuel cell's highly acidic solvents present in the reaction that converts hydrogen's chemical energy into electrical power. Only four elements can resist the corrosive process – platinum, iridium, gold and palladium. The first two are rare and expensive, which makes them impractical for large-scale use. The other two don't do well with the chemical reaction.

UCF Professor Sergey Stolbov and postdoctoral research associate Marisol Alcántara Ortigoza focused on making gold and palladium better suited for the reaction.

They created a sandwich-like structure that layers cheaper and more abundant elements with gold and palladium and other elements to make it more effective.

The outer monoatomic layer (the top of the sandwich) is either palladium or gold. Below it is a layer that works to enhance the energy conversion rate but also acts to protect the catalyst from the acidic environment. These two layers reside on the bottom slice of the sandwich -- an inexpensive substrate (tungsten), which also plays a role in the stability of the catalyst.

"We are very encouraged by our first attempts that suggest that we can create two cost-effective and highly active palladium- and gold-based catalysts –for hydrogen fuel cells, a clean and renewable energy source," Stolbov said.

Stolbov's work was recently published in the Journal of Physical Chemistry Letters.

By creating these structures, more energy is converted, and because the more expensive and rare metals are not used, the cost could be significantly less.

Stolbov said experiments are needed to test their predictions, but he says the approach is quite reliable. He's already working with a group within the U.S. Department of Energy to determine whether the results can be duplicated and have potential for large-scale application.

If a way could be found to make hydrogen fuel cells practical and cost effective, vehicles that run on gasoline and contribute to the destruction of the ozone layer could become a thing of the past.

Stolbov joined UCF's physics department in 2006. Before that he was a research assistant professor at Kansas State University. He earned multiple degrees in physics from Rostov State University in Russia and was a Postdoctoral Fellow at the Carnegie Institution of Washington, D.C. He is a frequent international speaker and has written dozens of articles on physics.

Provided by University of Central Florida (news : web)

Straintronics: Engineers create piezoelectric graphene

 In what became known as the 'Scotch tape technique," researchers first extracted graphene with a piece of adhesive in 2004. Graphene is a single layer of carbon atoms arranged in a honeycomb, hexagonal pattern. It looks like chicken wire.

Graphene is a wonder material. It is one-hundred-times better at conducting electricity than silicon. It is stronger than diamond. And, at just one atom thick, it is so thin as to be essentially a two-dimensional material. Such promising physics have made graphene the most studied substance of the last decade, particularly in nanotechnology. In 2010, the researchers who first isolated it shared the Nobel Prize.

Yet, while graphene is many things, it is not piezoelectric. Piezoelectricity is the property of some materials to produce electric charge when bent, squeezed or twisted. Perhaps more importantly, piezoelectricity is reversible. When an electric field is applied, piezoelectric materials change shape, yielding a remarkable level of engineering control.

Piezoelectrics have found application in countless devices from watches, radios and ultrasound to the push-button starters on propane grills, but these uses all require relatively large, three-dimensional quantities of piezoelectric materials.

Now, in a paper published in the journal ACS Nano, two materials engineers at Stanford have described how they have engineered piezoelectrics into graphene, extending for the first time such fine physical control to the nanoscale.

Straintronics

"The physical deformations we can create are directly proportional to the electrical field applied and this represents a fundamentally new way to control electronics at the nanoscale," said Evan Reed, head of the Materials Computation and Theory Group at Stanford and senior author of the study. "This phenomenon brings new dimension to the concept of 'straintronics' for the way the electrical field strains -- or deforms -- the lattice of carbon, causing it to change shape in predictable ways."

"Piezoelectric graphene could provide an unparalleled degree of electrical, optical or mechanical control for applications ranging from touchscreens to nanoscale transistors," said Mitchell Ong, a post-doctoral scholar in Reed's lab and first author of the paper.

Using a sophisticated modeling application running on high-performance supercomputers, the engineers simulated the deposition of atoms on one side of a graphene lattice -- a process known as doping -- and measured the piezoelectric effect.

They modeled graphene doped with lithium, hydrogen, potassium and fluorine, as well as combinations of hydrogen and fluorine and lithium and fluorine on either side of the lattice. Doping just one side of the graphene, or doping both sides with different atoms, is key to the process as it breaks graphene's perfect physical symmetry, which otherwise cancels the piezoelectric effect.

The results surprised both engineers.

"We thought the piezoelectric effect would be present, but relatively small. Yet, we were able to achieve piezoelectric levels comparable to traditional three-dimensional materials," said Reed. "It was pretty significant."

Designer piezoelectricity

"We were further able to fine tune the effect by pattern doping the graphene -- selectively placing atoms in specific sections and not others," said Ong. "We call it designer piezoelectricity because it allows us to strategically control where, when and how much the graphene is deformed by an applied electrical field with promising implications for engineering."

While the results in creating piezoelectric graphene are encouraging, the researchers believe that their technique might further be used to engineer piezoelectricity in nanotubes and other nanomaterials with applications ranging from electronics, photonics, and energy harvesting to chemical sensing and high-frequency acoustics.

"We're already looking now at new piezoelectric devices based on other 2D and low-dimensional materials hoping they might open new and dramatic possibilities in nanotechnology," said Reed.

The Army High Performance Computing Research Center at Stanford University (http://me.stanford.edu/research/centers/ahpcrc/index.html) and the National Energy Research Scientific Computing Center (NERSC) at the Lawrence Berkeley National Laboratory supported this research.

Listen to Reed and Ong talk about their work with ACS Nano: http://www.stanford.edu/group/evanreed/media/ancac3-0212.mp3

Story Source:

The above story is reprinted from materials provided by Stanford School of Engineering. The original article was written by Andrew Myers, associate director of communications for the Stanford University School of Engineering.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Mitchell T. Ong, Evan J. Reed. Engineered Piezoelectricity in Graphene. ACS Nano, 2012; 6 (2): 1387 DOI: 10.1021/nn204198g

Scientists create first atomic X-ray laser

ScienceDaily (Jan. 25, 2012) — Scientists working at the U.S. Department of Energy's (DOE) SLAC National Accelerator Laboratory have created the shortest, purest X-ray laser pulses ever achieved, fulfilling a 45-year-old prediction and opening the door to a new range of scientific discovery.

The researchers, reporting in Nature, aimed SLAC's Linac Coherent Light Source (LCLS) at a capsule of neon gas, setting off an avalanche of X-ray emissions to create the world's first "atomic X-ray laser."

"X-rays give us a penetrating view into the world of atoms and molecules," said physicist Nina Rohringer, who led the research. A group leader at the Max Planck Society's Advanced Study Group in Hamburg, Germany, Rohringer collaborated with researchers from SLAC, DOE's Lawrence Livermore National Laboratory and Colorado State University.

"We envision researchers using this new type of laser for all sorts of interesting things, such as teasing out the details of chemical reactions or watching biological molecules at work," she added. "The shorter the pulses, the faster the changes we can capture. And the purer the light, the sharper the details we can see."

The new atomic X-ray laser fulfills a 1967 prediction that X-ray lasers could be made in the same manner as many visible-light lasers -- by inducing electrons to fall from higher to lower energy levels within atoms, releasing a single color of light in the process. But until 2009, when LCLS turned on, no X-ray source was powerful enough to create this type of laser.

To make the atom laser, LCLS's powerful X-ray pulses -- each a billion times brighter than any available before -- knocked electrons out of the inner shells of many of the neon atoms in the capsule. When other electrons fell in to fill the holes, about one in 50 atoms responded by emitting a photon in the X-ray range, which has a very short wavelength. Those X-rays then stimulated neighboring neon atoms to emit more X-rays, creating a domino effect that amplified the laser light 200 million times.

Although LCLS and the neon capsule are both lasers, they create light in different ways and emit light with different attributes. The LCLS passes high-energy electrons through alternating magnetic fields to trigger production of X-rays; its X-ray pulses are brighter and much more powerful. The atomic laser's pulses are only one-eighth as long and their color is much more pure, qualities that will enable it to illuminate and distinguish details of ultrafast reactions that had been impossible to see before.

"This achievement opens the door for a new realm of X-ray capabilities," said John Bozek, LCLS instrument scientist. "Scientists will surely want new facilities to take advantage of this new type of laser."

For example, researchers envision using both LCLS and atomic laser pulses in a synchronized one-two punch: The first laser triggers a change in a sample under study, and the second records with atomic-scale precision any changes that occurred within a few quadrillionths of a second.

In future experiments, Rohringer says she will try to create even shorter-pulsed, higher-energy atomic X-ray lasers using oxygen, nitrogen or sulfur gas.

Additional authors included Richard London, Felicie Albert, James Dunn, Randal Hill and Stefan P. Hau-Riege from Lawrence Livermore National Laboratory (LLNL); Duncan Ryan, Michael Purvis and Jorge J. Rocca from Colorado State University; and Christoph Bostedt from SLAC.

The work was supported by Lawrence Livermore National Laboratory's Laboratory Directed Research and Development Program. Authors Roca, Purvis and Ryan were supported by the DOE Office of Science. LCLS is a national scientific user facility operated by SLAC and supported by DOE's Office of Science.

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The above story is reprinted from materials provided by DOE/SLAC National Accelerator Laboratory.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Nina Rohringer, Duncan Ryan, Richard A. London, Michael Purvis, Felicie Albert, James Dunn, John D. Bozek, Christoph Bostedt, Alexander Graf, Randal Hill, Stefan P. Hau-Riege, Jorge J. Rocca. Atomic inner-shell X-ray laser at 1.46 nanometres pumped by an X-ray free-electron laser. Nature, 2012; 481 (7382): 488 DOI: 10.1038/nature10721

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Scientists create novel RNA repair technology

The new study, published January 17, 2012 in an advance, online edition of the journal ACS Chemical Biology, describes a method to find compounds that target defective RNAs, specifically RNA that carries a structural motif known as an "expanded triplet repeat." The triplet repeat, a series of three nucleotides repeated many more times than normal in the genetic code of affected individuals, has been associated with a variety of neurological and neuromuscular disorders.

"For a long time it was thought that only the protein translated from this type of RNA was toxic," said Matthew Disney, an associate professor at Scripps Florida who led the new study. "But it has been shown recently that both the protein and the RNA are toxic. Our discovery of a small molecule that binds to RNA and shuts off its toxicity not only further demonstrates that the RNA is toxic but also opens up new avenues for therapeutic development because we have clearly demonstrated that small molecules can reverse this type of defect."

In the new research, the scientists used a query molecule called 4', 6-diamidino-2-phenylindole (DAPI) as a chemical and structural template to find similar but more active compounds to inhibit a toxic CAG triplet repeat. One of these compounds was then found effective in inhibiting the RNS toxicity of the repeat in patient-derived cells, which demonstrated an improvement in early-stage abnormalities.

"The toxic RNA defect actually sucks up other proteins that play critical roles in RNA processing, and that is what contributes to these various diseases," Disney said. "Our new compound targets the toxic RNA and inhibits protein binding, shutting off the toxicity. Since the development of drugs that target RNA is extremely challenging, these studies can open up new avenues to exploit RNA drug targets that cause a host of other RNA-mediated diseases."

Disney and his colleagues are already hard at work to extend the lab's findings.

More information: "Chemical Correction of Pre-mRNA Splicing Defects Associated with Sequestration of Muscleblind-Like 1 Protein by Expanded r(CAG)-containing Transcripts," Amit Kumar et al. http://pubs.acs.or … 21/cb200413a

Provided by The Scripps Research Institute (news : web)

Scientists create a functional model of the extracellular matrix

The extracellular matrix (ECM) provides the physical and chemical conditions that enable the development of all biological tissues. It is a complex nano-to-microscale structure made up of protein fibres and serves as a dynamic substrate that supports tissue repair and regeneration.

Man-made structures designed to mimic and replace the native matrix in damaged or diseased tissues are highly sought after to advance our understanding of tissue organisation and to make regenerative medicine a reality.

Self-assembling peptide fibres that have similar properties to those of the native matrices are of particular interest. However, these near-crystalline nanostructures fail to arrange themselves into interconnected meshes at the microscopic scale, which is critical for bringing cells together and supporting tissue development.

To solve this problem, a research team at NPL designed a small protein consisting of two complementary domains (structural units) that promote the formation of highly branched networks of fibres that span microscopic dimensions. The team showed that the created matrix is very efficient in supporting cell attachment, growth and proliferation.

Max Ryadnov, the lead researcher at NPL, said: "The extracellular matrix is a cellular "scaffolding", which provides necessary signalling environment for cell growth and development into tissues and can help to heal wounds and other damaged tissues. Therefore, extracellular mimetics such as one developed by NPL could be useful for the progress of regenerative medicine."

More information: The full research was published recently in Angewandte Chemie. It is available here: http://onlinelibrary.wiley.com/doi/10.1002/anie.201104647/abstract

Provided by National Physical Laboratory

Swiss researchers create unscratchable gold

By combining a gold alloy with boron carbide, an extremely hard ceramic that’s used in bulletproof vests, a team of EPFL researchers has succeeded in making the world’s toughest 18-karat gold (75% gold). With a Vickers hardness number of 1000, it’s harder than most tempered steels (600 Vickers) and thus almost impossible to scratch, except with a diamond. This discovery is the result of a three-year collaboration between the Mechanical Metallurgy Laboratory in EPFL’s Institute of Materials, under the leadership of Professor Andreas Mortensen, and the Swiss watchmaking company Hublot.

The process for developing this material is relatively complicated. Powdered boron carbide is heated to almost 2000°C, where it forms a rigid, porous structure by a process called sintering. A liquid molten alloy of gold is infiltrated under very high pressure into the pores of this structure, and then solidified, yielding a pore-free composite material. The final material is thus made up of two kinds of crystals that are intimately interconnected in space, like two three-dimensional labyrinths. Because the molten gold used is a previously-made alloy based on 24-karat gold and aluminum (3%) for strength, the final gold is thus 3% aluminum, 75% gold and 22% boron carbide
.
By definition, gold is very soft. Managing to harden it to this degree while still maintaining 18-karat purity was a real challenge for the EPFL scientists. They overcame the obstacle by taking the ceramic-metal composite approach. Composite materials are created by artificially combining several materials that conserve their individual characteristics even after they’re assembled. In this they are different from alloys, in which atoms mix together to form a new, homogeneous, material.

The EPFL researchers aren’t the first to play around with different materials in an effort to make more resistant gold. They are, however, the first to have attained this degree of hardness in 18-karat gold. The first watches made using this new gold will be presented in 2012 at BaselWorld, the world watch and jewelry show.

Provided by Ecole Polytechnique Federale de Lausanne

Chemists devise a way to create a five point knotted molecule

Called a pentafoil, the five point knot is the most complex kind of molecule synthesized from other building blocks, other than those found in DNA, and having a means for building them could lead to all sorts of new materials that could be both strong and flexible.

To build the molecule, the team started with a negatively charged chloride ion, to serve as a pulling force, or anchor. They then added other parts, such as iron ions with a positive charge, and chains of carbon atoms. They then chemically “programmed” the whole works to assemble itself into the pentafoil, with five chains looped over and under one another and connected to form one single knotted strand, with a single chloride ion sitting squarely in the center holding the whole knot together. The finished product is made up of just 160 atoms and very much resembles a traditional two-dimensional five pointed star.

As an interesting side note, the researchers found that if they removed the single chloride ion after the knot was completed, they were left with a molecule that was hungry for that missing ion, which could mean they’ve found a new type of chlorine sensor.

In devising a means to create a pentafoil, the researchers have created not just a new type of man-made molecule, but a blueprint for creating other types of knotted molecules which could lead to all sorts of new and exotic materials.

More information: A synthetic molecular pentafoil knot, Nature Chemistry 4, 15–20 (2012) doi:10.1038/nchem.1193

Abstract
Knots are being discovered with increasing frequency in both biological and synthetic macromolecules and have been fundamental topological targets for chemical synthesis for the past two decades. Here, we report on the synthesis of the most complex non-DNA molecular knot prepared to date: the self-assembly of five bis-aldehyde and five bis-amine building blocks about five metal cations and one chloride anion to form a 160-atom-loop molecular pentafoil knot (five crossing points). The structure and topology of the knot is established by NMR spectroscopy, mass spectrometry and X-ray crystallography, revealing a symmetrical closed-loop double helicate with the chloride anion held at the centre of the pentafoil knot by ten CH···Cl– hydrogen bonds. The one-pot self-assembly reaction features an exceptional number of different design elements—some well precedented and others less well known within the context of directing the formation of (supra)molecular species. We anticipate that the strategies and tactics used here can be applied to the rational synthesis of other higher-order interlocked molecular architectures.

? 2011 PhysOrg.com

New process for manufacturing nanocellulose: Using nanocellulose to create novel composite materials

For some time now nanocellulose has been at the focus of a good deal of industrial and scientific interest as a novel biomaterial. Potential applications range from the creation of new kinds of commercially useful materials and uses in medical technology all the way to the food and pharmaceutical industries. Researchers with Switzerland's Empa research institute have now developed a manufacturing process for nanocellulose powder, the raw material for creating polymer composites which can be used, for example, in lightweight structures for the car industry or as membrane and filter material for biomedicinal applications.

Cellulose is a biopolymer consisting of long chains of glucose with unique structural properties whose supply is practically inexhaustible. It is found in the cell walls of plants where it serves to provide a supporting framework -- a sort of skeleton. Cellulose is extremely strong in tension and can be chemically modified in many ways, thereby changing its characteristics. It is also biodegradable. In the search for novel polymer materials with certain desirable characteristics material scientists have developed such substances as high performance composites in which nanofibers of cellulose are embedded. In the form of lightweight structural material, these composites have similar mechanical properties to steel, while as nanoporous "bio"-foam they provide an alternative to conventional insulating materials.

The ideal lightweight structural material

Classical cellulose chemistry on the industrial scale is primarily used in the wood pulp, paper and fiber industry. Commercial research is currently focused on isolating and characterizing cellulose in the form of nanofibers. So-called nanocellulose consists of fibers or crystals with a diameter of less than 100 nm. Material scientists hope to be able to use nanocellulose to create new lightweight materials boasting high mechanical strength -- in short the ideal material for creating lightweight structures.

The cellulose experts in Empa's Wood Laboratory isolated cellulose nanofibers from wood pulp. These are several micrometers long but only a few nanometers thick and are closely interlinked. The fibers have an extremely large surface area on which chemical-physical reactions with substances such as water, organic and inorganic chemicals and polymer compounds can occur. Cellulose nanofibers can therefore be used as stable, extremely reactive raw materials for technical applications while boasting the additional advantages of being biologically produced and biodegradable. Such applications include reinforcing (bio-)polymers to create very promising, environmentally safe, lightweight construction material for the car industry, as well as membrane or filter materials for applications in packaging and biomedicine.

The solution lies in chemical modification

Nanocellulose isolated from wood pulp is initially in the form of a water-based suspension. If the material dries out the cellulose fibers stick together forming rough clumps and it loses its outstanding mechanical properties. For this reason the Empa researchers sought to develop a process which allowed them to dry nanocellulose without it clumping and becoming rough. To achieve this, the cellulose was treated using a technique which is easily implemented on a large scale and is also completely harmless, even being suitable for applications in the food industry. The method prevents the cellulose fibrils from forming clumps and sticking together

The results are worth looking at: after being re-dispersed in water the dried nanocellulose powder boasts the same outstanding properties as undried, unmodified cellulose. This makes the new product an attractive alternative to conventional cellulose suspensions for the synthesis of bio-nanocomposite materials. Suspensions currently in use consists of over 90% water which causes the transport costs to explode and increases the danger of degradation by bacteria or fungi. In addition aquatic cellulose suspensions are laborious to work with since usually in the course of chemical processing solvents must be exchanged.

Empa Research Prize 2011 goes to Christian Eyholzer

The work on developing the new manufacturing process and identifying applications for nanocellulose in various biopolymers was recently recognized with the award of the Empa Research Prize 2011. In a collaborative project with the "Lulea University of Technology," Sweden, Empa researcher and PhD student Christian Eyholzer and his co-workers used the novel nanocellulose powder to reinforce adhesives, hydrogels and biodegradable synthetics. After completing his doctoral dissertation Eyholzer left Empa and is currently employed by Sika as project leader in the product development department.

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The above story is reprinted from materials provided by Empa. The original article was written by Nina Baiker.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Scientists and engineers create the 'perfect plastic'

 Researchers at the University of Leeds and Durham University have solved a long-standing problem that could revolutionize the way new plastics are developed. The breakthrough will allow experts to create the 'perfect plastic' with specific uses and properties by using a high-tech 'recipe book.' It will also increase our ability to recycle plastics. The research paper is published in the journal Science on September 29.

The paper's authors form part of the Microscale Polymer Processing project, a collaboration between academics and industry experts which has spent 10 years exploring how to better build giant 'macromolecules.' These long tangled molecules are the basic components of plastics and dictate their properties during the melting, flowing and forming processes in plastics production.

Low-density polyethylenes (LDPEs) are used in trays and containers, lightweight car parts, recyclable packaging and electrical goods. Up until now, industry developed a plastic then found a use for it, or tried hundreds of different "recipes" to see which worked. This method could save the manufacturing industry time, energy and money.

The mathematical models used put together two pieces of computer code. The first predicts how polymers will flow based on the connections between the string-like molecules they are made from. A second piece of code predicts the shapes that these molecules will take when they are created at a chemical level. These models were enhanced by experiments on carefully synthesised 'perfect polymers' created in labs of the Microscale Polymer Processing project.

Dr. Daniel Read, from the School of Mathematics, University of Leeds, who led the research, said, "Plastics are used by everybody, every day, but until now their production has been effectively guesswork. This breakthrough means that new plastics can be created more efficiently and with a specific use in mind, with benefits to industry and the environment."

Professor Tom McLeish, formerly of the University of Leeds, now Pro-Vice Chancellor for Research at Durham University leads the Microscale Polymer Processing project. He said, "After years of trying different chemical recipes and finding only a very few provide useable products, this new science provides industry with a toolkit to bring new materials to market faster and more efficiently."

Professor McLeish added that as plastics production moves from oil-based materials to sustainable and renewable materials, the "trial and error" phase in developing new plastics could now be by-passed. He said, "By changing two or three numbers in the computer code, we can adapt all the predictions for new bio-polymer sources."

"This is a wonderful outcome of years of work by this extraordinary team. It's a testimony to the strong collaborative ethos of the UK research groups and global companies involved," he added.

Dr. Ian Robinson of Lucite International, one of the industrial participants in the wider project said, "The insights offered by this approach are comparable to cracking a plastics 'DNA.'"

The model was developed by Dr. Daniel Read, School of Mathematics, University of Leeds, Dr. Chinmay Das of the School of Physics & Astronomy, University of Leeds and Professor Tom McLeish, Department of Physics, Durham University. Their predictions were compared to the results of polymer analysis by Dr. Dietmar Auhl, at the time a physicist at Leeds.

The research was carried out at the University of Leeds, Durham University, LyondellBasell and Dow Chemical and was funded by the Engineering and Physical Sciences Research Council and the European Union.

The Microscale Polymer Processing collaboration includes researchers from the universities of Durham, Bradford, Cambridge, Leeds, Nottingham, Oxford, Reading, Sheffield and University College London alongside their industry counterparts from Lucite International, Ineos, LyondellBasell, BASF, Dow Chemical, DSM, and Mitsubishi.

Story Source:

The above story is reprinted (with editorial adaptations ) from materials provided by University of Leeds, via EurekAlert!, a service of AAAS.

Journal Reference:

D. J. Read, D. Auhl, C. Das, J. den Doelder, M. Kapnistos, I. Vittorias, T. C. B. McLeish. Linking Models of Polymerization and Dynamics to Predict Branched Polymer Structure and Flow. Science, 2011; 333 (6051): 1871 DOI: 10.1126/science.1207060

Discovery could create retinas from 'Jell-O'

Researchers at the University of Toronto have developed a new method for creating 3D hydrogel scaffolds that will aid in the development of new tissue and organs grown in a lab.

The discovery is outlined in the latest issue of Nature Materials. Watch a video below.

Hydrogels, a “Jell-O”-like substance, are highly flexible and absorbent networks of polymer strings that are frequently used in tissue engineering to act as a scaffold to aid cellular growth and development.

The paper demonstrates for the first time that it is possible to immobilize different proteins simultaneously using a hydrogel. This is critical for controlling the determination of stem cells, which are used to engineer new tissue or organs.

“We know that proteins are very important to define cell function and cell fate. So working with stem cells derived from the brain or retina we have demonstrated we can spatially immobilize proteins that will influence their differentiation in a three-dimensional environment,” explained Professor Molly Shoichet of the Department of Chemical Engineering & Applied Chemistry, the Institute for Biomaterials & Biomedical Engineering and the Department of Chemistry.

Immobilizing proteins maintains their bioactivity, which had previously been difficult to ensure. It is also important to maintain spacial control as the tissue and organs are three-dimensional. Therefore, being able to control cell fate and understanding how cells interact across three dimensions is critical.

“If we think about the retina, the retina is divided into seven layers. And if you start with a retinal stem cell, it has the potential to become all of those different cell types. So what we are doing is immobilizing a protein which will cause their differentiation into photoreceptors or bipolar neurons or other cell types that would make up those seven different cell types,” said Shoichet.

The end result is a new hydrogel that can guide stem cell development in three-dimensions.

Shoichet identifies two long-term outcomes from this discovery.

“We could use... it as a platform technology to look at the interaction of different cells and build tissues and organ,” Shoichet stated, while also noting that it could help lead to a more fundamental understanding of cellular interaction. “By growing cells in a 3D environment, similar to how they grow in our body, we can develop a better understanding of cell processes and interactions.”

The research was led by Shoichet and was conducted by Ryan G. Wylie, Shoeb Ahsan, Yukie Aizawa, Karen L. Maxwell and Cindi M. Morshead.

Provided by University of Toronto (news : web)

Scientists create natural Alzheimer's-fighting compound in lab

Scientists at Yale University have developed the first practical method to create a compound called huperzine A in the lab. The compound, which occurs naturally in a species of moss found in China, is an enzyme inhibitor that has been used to treat Alzheimer's disease in China since the late 1990s and is sold in the U.S. as a dietary supplement to help maintain memory. Scientists believe it could also potentially combat the effects of chemical warfare agents.

Until now, researchers have only been able to derive small amounts of the compound directly from the Huperzia serrata plant, or had to resort to lengthy and cumbersome methods to synthesize it in the lab.

Now researchers at Yale have developed a practical and cost-effective method to synthesize huperzine A in the lab. The process requires just eight steps and produces a yield of 40 percent. Previously, the best synthetic techniques had required twice as many steps and achieved yields of only two percent.

"Being able to synthesize large amounts of huperzine A in the lab is crucial because the plant itself, which has been used in Chinese folk medicine for centuries, takes decades to grow and is nearing extinction due to overharvesting," said Seth Herzon, the Yale chemist who led the research, which is described in the Aug. 25 issue of the journal Chemical Science.

In some places, huperzine A can cost up to $1,000 per milligram. Herzon and his team produced several grams of the compound in their lab and are capable of creating much more. They believe they will be able to drive the cost down to just 50 cents per milligram (a projected typical dose is about one milligram per day), and have partnered with an industrial firm to help produce it on larger scales.

The firm plans to comprehensively evaluate the therapeutic potential of huperzine A by conducting clinical trials for several different neurological disorders in the U.S. In addition, the Herzon lab and the firm are working with the U.S. Army, which is interested in huperzine A's potential in blocking the effects of chemical warfare agents, he said. The compound has been shown to protect primates against chemical warfare agents, without side effects.

Other Alzheimer's treatments based on enzyme inhibitors are currently prescribed in the U.S., but huperzine A binds better, is more easily absorbed by the body and last longer in the body than other treatments, Herzon said.

"We believe huperzine A has the potential to treat a range of neurologic disorders more effectively than the current options available," Herzon said. "And we now have a route to huperzine A that rivals nature's pathway."

Provided by Yale University (news : web)

Engineers create polymer light-emitting devices that can be stretched like rubber

Stretchable electronics, an emerging class of modern electronic materials that can bend and stretch, have the potential to be used in a wide range of applications, including wearable electronics, "smart skins" and minimally invasive biomedical devices that can move with the body.

Today's conventional inorganic electronic devices are brittle, and while they have a certain flexibility achieved using ultrathin layers of inorganic materials, these devices are either flexible, meaning they can be bent, or they are stretchable, containing a discrete LED chip interconnected with stretchable electrodes. But they lack "intrinsic stretchabilty," in which every part of the device is stretchable.

Now, researchers at the UCLA Henry Samueli School of Engineering and Applied Science have demonstrated for the first time an intrinsically stretchable polymer light-emitting device. They developed a simple process to fabricate the transparent devices using single-walled carbon nanotube polymer composite electrodes. The interpenetrating networks of nanotubes and the polymer matrix in the surface layer of the composites lead to low sheet resistance, high transparency, high compliance and low surface roughness.
The metal-free devices can be linearly stretched up to 45 percent and the composite electrodes can be reversibly stretched by up to 50 percent with little change in sheet resistance.

Because the devices are fabricated by roll lamination of two composite electrodes that sandwich an emissive polymer layer, they uniquely combine mechanical robustness and the ability for large-strain deformation, due to the shape-memory property of the composite electrodes. This development will provide a new direction for the field of stretchable electronics.

This research was recently published in the peer-reviewed journal Advanced Materials .

More information: DOI: 10.1002/adma.201101986

Provided by University of California Los Angeles (news : web)

Researchers create more powerful 'lab-on-a-chip' for genetic analysis

UBC researchers have invented a silicone chip that could make genetic analysis far more sensitive, rapid, and cost-effective by allowing individual cells to fall into place like balls in a pinball machine.

The UBC device – about the size of a nine-volt battery – allows scientists to simultaneously analyze 300 cells individually by routing fluid carrying cells through microscopic tubes and valves. Once isolated into their separate chambers, the cells' RNA can be extracted and replicated for further analysis.

By enabling such "single-cell analysis," the device could accelerate genetic research and hasten the use of far more detailed tests for diagnosing cancer.

Single-cell analysis is emerging as the gold standard of genetic research because tissue samples, even those taken from a single tumour, contain a mixture of normal cells and various types of cancer cells – the most important of which may be present in only very small numbers and impossible to distinguish.

So standard genetic tests, which require large numbers of cells, capture only an average "composite picture" of thousands or millions of different cells – obscuring their true nature and the interactions between them.

"It's like trying to trying to understand what makes a strawberry different from a raspberry by studying a blended fruit smoothie," says Carl Hansen, an assistant professor in the Dept. of Physics and Astronomy and the Centre for High-Throughput Biology, who led the team that developed the device.

The device, described and validated in this week's issue of the Proceedings of the National Academy of Sciences, was developed by Hansen's team, in collaboration with researchers from BC Cancer Agency and the Centre for Translational and Applied Genomics.

The device's ease of use and cost-effectiveness arise from its integration of almost the entire process of cell analysis – not just separating the cells, but mixing them with chemical reagents to highlight their genetic code and analyzing the results by measuring fluorescent light emitted from the reaction. Now all of that can be done on the chip.

"Single-cell genetic analysis is vital in a host of areas, including stem cell research and advanced cancer biology and diagnostics," Hansen says. "But until now, it has been too costly to become widespread in research, and especially for use in health care. This technology, and other approaches like it, could radically change the way we do both basic and applied biomedical research, and would make single-cell analysis a more plausible option for treating patients – allowing clinicians to distinguish various cancers from one another and tailor their treatments accordingly."

Provided by University of British Columbia (news : web)

Chemists create molecular polyhedron

Chemists have created a molecular polyhedron, a ground-breaking assembly that has the potential to impact a range of industrial and consumer products, including magnetic and optical materials.

The work, reported in the latest issue of the journal Science, was conducted by researchers at New York University's Department of Chemistry and its Molecular Design Institute and the University of Milan's Department of Materials Science.

Researchers have sought to coerce molecules to form regular polyhedra—three-dimensional objects in which each side, or face, is a polygon—but without sustained success. Archimedean solids, discovered by the ancient Greek mathematician Archimedes, have attracted considerable attention in this regard. These 13 solids are those in which each face is a regular polygon and in which around every vertex—the corner at which its geometric shapes meet—the same polygons appear in the same sequences. For instance, in a truncated tetrahedron, the pattern forming at every vertex is hexagon-hexagon-triangle. The synthesis of such structures from molecules is an intellectual challenge.

The work by the NYU and University of Milan chemists forms a quasi-truncated octahedron, which also constitutes one of the 13 Archimedean solids. Moreover, as a polyhedron, the structure has the potential to serve as a cage-like framework to trap other molecular species, which can jointly serve as building blocks for new and enhanced materials.

"We've demonstrated how to coerce molecules to assemble into a polyhedron by design," explained Michael Ward, chair of NYU's Department of Chemistry and one of the study's co-authors. "The next step will be to expand on the work by making other polyhedra using similar design principles, which can lead to new materials with unusual properties."

The research team's creation relies on a remarkably high number of hydrogen bonds—72—to assemble two kinds of hexagonal molecular tiles, four each, into a truncated octahedron, which consists of eight molecular tiles. Although chemists often use hydrogen bonds because of their versatility in building complex structures, these bonds are weaker than those holding atoms together within the molecules themselves, which often makes larger scale structures constructed with hydrogen bonds less predictable and less sustainable. The truncated octahedron discovered by the NYU team proved to be remarkably stable, however, because the hydrogen bonds are stabilized by the ionic nature of the molecules and because no other outcomes are possible. In fact, the truncated octahedra assemble further into crystals that have nanoscale pores, resembling a class of well-known compounds called zeolites, which are made from inorganic components.

Because the structure also serves as a molecular cage, it can house, or encapsulate, other molecular components, giving future chemists a vehicle for developing a range of new compounds.

Provided by New York University (news : web)

Scientists create vaccine against heroin high

Researchers at The Scripps Research Institute have developed a highly successful vaccine against a heroin high and have proven its therapeutic potential in animal models.

The new study, published recently online ahead of print by the American Chemical Society's Journal of Medicinal Chemistry, demonstrates how a novel vaccine produces antibodies (a kind of immune molecule) that stop not only heroin but also other psychoactive compounds metabolized from heroin from reaching the brain to produce euphoric effects.

"In my 25 years of making drug-of-abuse vaccines, I haven't seen such a strong immune response as I have with what we term a dynamic anti-heroin vaccine," said the study's principal investigator, Kim D. Janda, the Ely R. Callaway, Jr. Chair in Chemistry and a member of The Skaggs Institute for Chemical Biology at Scripps Research. "It is just extremely effective. The hope is that such a protective vaccine will be an effective therapeutic option for those trying to break their addiction to heroin."

"We saw a very robust and specific response from this heroin vaccine," said George F. Koob, chair of the Scripps Research Committee on the Neurobiology of Addictive Disorders and a co-author of the new study. "I think a humanized version could be of real help to those who need and want it."

A Worldwide Epidemic

While injection drug abuse is a debilitating worldwide epidemic, heroin abuse and addiction are especially destructive, with costs estimated at $22 billion in the United States due to loss of productivity, criminal activity, medical care, and social welfare, the authors say in their study.

Heroin abuse and addiction are also driving forces in the spread of HIV through needle sharing.

Using an approach termed "immunopharmacotherapy," Janda and his Scripps Research colleagues previously created vaccines that used immune molecules to blunt the effects of other abused drugs such as cocaine, methamphetamine, and nicotine. Human clinical trials are under way for the cocaine and nicotine vaccines.

Attempts by other researchers over the past four decades to create a clinically viable heroin vaccine, however, have fallen short, in part due to the fact that heroin is an elusive target metabolized into multiple substances each producing psychoactive effects.

An Innovative Approach

To overcome this problem, in the new study the Scripps Research team used a "dynamic" approach, targeting not only heroin itself, but also the chemical it quickly degrades into, 6-acetylmorphine (6AM), and morphine.

"Heroin is lipophilic and is rapidly degraded to 6AM," said G. Neil Stowe, a research associate in Janda's laboratory who is first author of the new study. "Both readily cross the blood-brain barrier and gain access to the opioid receptors in the brain."

The researchers linked a heroin-like hapten (a small molecule that elicits an immune response) to a generic carrier protein called keyhole limpet hemocyanin or KLH, and mixed it with Alum, an adjuvant (vaccine additive), to create a vaccine "cocktail." This mixture slowly degraded in the body, exposing the immune system to different psychoactive metabolites of heroin such as 6AM and morphine.

"Critically, the vaccine produces antibodies to a constantly changing drug target," said Stowe. "Such an approach has never before been engaged with drug-of-abuse vaccines."

To compare the results of a non-dynamic approach, the team also prepared a vaccine simply targeting morphine, a substance related to heroin. Both vaccines were then injected into rats and the effects were examined in Koob's laboratory.

Promising Results

The results showed that the rats rapidly generated robust polyclonal antibodies in response to the dynamic heroin vaccine.

In addition, the study found that addicted rats were less likely to "self-administer" heroin by pressing on a lever after several booster shots of the vaccine. Only three of the seven rats that received the heroin vaccine self-administered heroin. In contrast, all of the control rats, including those given the morphine vaccine, self-administered the drug.

The effect of the heroin vaccine "was very dramatic; as dramatic as we have ever seen in experiments of this kind," said Koob. "To have an animal vaccinated and not show a response to heroin is pretty amazing."

The team also found that the heroin vaccine was highly specific, meaning that it only produced an antibody response to heroin and 6AM, and not to the other opioid-related drugs tested, such as oxycodone as well as drugs used for opioid dependence—methadone, naltrexone, and naloxone. "The importance of this," said Janda, "is that it indicates these vaccines could be used in combination with other heroin rehabilitation therapies."

The Scripps Research team has recently begun an exciting collaboration with researchers at the Walter Reed Army Institute of Research to see if it is feasible to develop a dual-purpose vaccine against HIV and for the treatment of heroin addiction in a single shot, Janda said.

More information: A Vaccine Strategy that Induces Protective Immunity Against Heroin, http://pubs.acs.or … 21/jm200461m

Provided by The Scripps Research Institute (news : web)

Chemists create molecular polyhedron -- and potential to enhance industrial and consumer products

Chemists have created a molecular polyhedron, a ground-breaking assembly that has the potential to impact a range of industrial and consumer products, including magnetic and optical materials.

The work, reported in the latest issue of the journal Science, was conducted by researchers at New York University's Department of Chemistry and its Molecular Design Institute and the University of Milan's Department of Materials Science.

Researchers have sought to coerce molecules to form regular polyhedra -- three-dimensional objects in which each side, or face, is a polygon -- but without sustained success. Archimedean solids, discovered by the ancient Greek mathematician Archimedes, have attracted considerable attention in this regard. These 13 solids are those in which each face is a regular polygon and in which around every vertex -- the corner at which its geometric shapes meet -- the same polygons appear in the same sequences. For instance, in a truncated tetrahedron, the pattern forming at every vertex is hexagon-hexagon-triangle. The synthesis of such structures from molecules is an intellectual challenge.

The work by the NYU and University of Milan chemists forms a quasi-truncated octahedron, which also constitutes one of the 13 Archimedean solids. Moreover, as a polyhedron, the structure has the potential to serve as a cage-like framework to trap other molecular species, which can jointly serve as building blocks for new and enhanced materials.

"We've demonstrated how to coerce molecules to assemble into a polyhedron by design," explained Michael Ward, chair of NYU's Department of Chemistry and one of the study's co-authors. "The next step will be to expand on the work by making other polyhedra using similar design principles, which can lead to new materials with unusual properties."

The research team's creation relies on a remarkably high number of hydrogen bonds -- 72 -- to assemble two kinds of hexagonal molecular tiles, four each, into a truncated octahedron, which consists of eight molecular tiles. Although chemists often use hydrogen bonds because of their versatility in building complex structures, these bonds are weaker than those holding atoms together within the molecules themselves, which often makes larger scale structures constructed with hydrogen bonds less predictable and less sustainable. The truncated octahedron discovered by the NYU team proved to be remarkably stable, however, because the hydrogen bonds are stabilized by the ionic nature of the molecules and because no other outcomes are possible. In fact, the truncated octahedra assemble further into crystals that have nanoscale pores, resembling a class of well-known compounds called zeolites, which are made from inorganic components.

Because the structure also serves as a molecular cage, it can house, or encapsulate, other molecular components, giving future chemists a vehicle for developing a range of new compounds.

The study's other co-authors were Yuzhou Liu, a graduate student, and Chunhua Hu, a researcher professor, in NYU's Department of Chemistry and Molecular Design Institute and Professor Angiolina Comotti of the University of Milan's Department of Materials Science.

Story Source:

The above story is reprinted (with editorial adaptations) from materials provided by New York University, via EurekAlert!, a service of AAAS.

Journal Reference:

Yuzhou Liu, Chunhua Hu, Angiolina Comotti, Michael D. Ward. Supramolecular Archimedean Cages Assembled with 72 Hydrogen Bonds. Science, 2011; 333 (6041): 436-440 DOI: 10.1126/science.1204369

Chemists create molecular flasks: Researchers design a self-assembling material that can house other molecules

Chemical reactions happen all of the time: some things burn or rust, others react to light exposure--even batteries use chemical reactions to supply electricity. One of the big challenges chemists continually face is finding new ways to control these reactions or create conditions that promote desirable reactions and limit undesirable ones.

Recently, researchers at New York University demonstrated an ability to make new materials with empty space on the inside, which could potentially control desired and unwanted chemical reactions.

Mike Ward, of NYU's Department of Chemistry and a team of researchers, essentially created a "molecular flask," self-assembling cages capable of housing other compounds inside of them. These "flasks" may eventually allow researchers to isolate certain chemical reactions within or outside the cage.

The research is published in the July 22, 2011 issue of the journal Science.

"We wanted to create frameworks to serve as the 'hotel' for 'guest' molecules, which can deliver the function independent of framework design," said Ward. "This makes it possible to separate chemicals based on size or perform reactions inside well-defined cages, which could potentially give you more control over chemical reactivity and reaction products. Moreover, these frameworks may prove ideal for encapsulating a wide range of guest molecules, producing materials with new optical or magnetic properties."

The molecular "hotels" described by Ward and his collaborators take the shape of a truncated octahedron, one of 13 shapes described as an Archimedean solid, discovered by the Greek mathematician Archimedes. Archimedean solids are characterized by a specific number of sides that meet at corners which are all identical. The regularity of these shapes often means they are of particular interest to chemists and materials researchers looking to create complex materials that assemble themselves.

The extraordinary aspect of this work, supported by the National Science Foundation (NSF), is the self-assembly of the molecular tiles into a polyhedron, a well-defined, three-dimensional, geometric solid. The individual polyhedra assemble themselves using the attractive interactions associated with hydrogen bonds. They then further organize into a crystal lattice that resembles a porous structure called zeolite, an absorbent material with many industrial uses.

The new material differs from zeolite because it is constructed from organic building blocks rather than inorganic ones, which make it more versatile and easier to engineer. In general, inorganic compounds are considered mineral in origin, while organic compounds are considered biological in origin.

This discovery paves the way towards development of a new class of solids with properties that may prove useful for a range of industrial and consumer products.

"By using geometric design principles and very simple chemical precursors, the Ward group has been able to construct relatively sturdy materials which contain many identically sized and shaped cavities," explained Michael Scott, program director in the Division of Materials Research at NSF. "The hollow space inside these materials offers many exciting opportunities for chemists to do things such as isolate unstable molecules, catalyze unknown reactions and separate important chemical compounds."

Future research projects will try to create other types of Archimedean solids or use the truncated octahedron to house different types of functional molecules.

Story Source:

The above story is reprinted (with editorial adaptations) from materials provided by National Science Foundation.

Journal Reference:

Yuzhou Liu, Chunhua Hu, Angiolina Comotti, Michael D. Ward. Supramolecular Archimedean Cages Assembled with 72 Hydrogen Bonds. Science, 2011; 333 (6041): 436-440 DOI: 10.1126/science.1204369

Inspired by teflon, researchers create super durable proteins

More than 50 years ago, NYU-Poly alumni John Gilbert was asked to evaluate a newly- developed material called Teflon. His experiments using the fluorinated polymer as a surface coating for pots and pans helped usher in a revolution in non-stick cookware. Today, NYU-Poly Assistant Professor of Chemical and Biological Sciences Jin Montclare is taking the research theme in a new direction, investigating fluorinated proteins -- a unique class of proteins that may have a wide range of applications from industrial detergents to medical therapeutics.

In a paper published in the current issue of ChemBioChem, Montclare and Peter Baker, who just received his doctoral degree from NYU-Poly, detail their success in creating proteins that are considerably more stable and less prone to denaturation than their natural counterparts. These qualities enable them to retain both their structure and function under high temperatures in which other proteins would simply break down.

Inspired by the ability of fluorinated polymers like Teflon to stabilize surfaces, Montclare and Baker set their sights on developing a process that would allow them to reinforce the interface of proteins, rendering them more resistant to degradation.

“One of the main challenges of proteins—whether they’re in the body or in the lab—is that they are naturally created to function under specific conditions, and to break down under others,” Montclare explained. “A stable protein that was still active and functional under a variety of conditions would open up an extraordinary range of potential for scientists and product developers.”

Through a trick of genetic engineering, the scientists were able to coax a strain of bacteria into taking up amino acids—the building blocks of protein—that were chemically altered by the addition of fluorine. “Nature doesn’t make fluorinated amino acids, but these experiments show that we can create them,” said Montclare. The result was a "fluorinated" protein that can withstand temperatures up to 140 degrees Fahrenheit with no compromise in activity or function.

Next up for Montclare and Baker are experiments to test the limits of their success in creating fluorinated or Teflon-like proteins. They’re hoping that this type of effect can be achieved with a wide range of proteins, especially those used in medicine including some therapeutic cancer drugs. The stable proteins may also some day act as prophylactics to combat exposure to neurotoxic agents (including warfare agents)–something that is of interest to the Department of Defense. The scientists hope to improve the proteins’durability and decrease the need for precise storage conditions, which often include refrigeration to prevent breakdown.

More information: Paper online: http://dx.doi.org/ … ic.201100221

Provided by Polytechnic Institute of New York University