(NanoRealm) - Graphene, a one-atom-thick layer of a carbon lattice with a honeycomb structure, has great potential for use in radios, computers, phones and other electronic devices. But applications have been stymied because the semi-metallic graphene, which has a zero band gap, does not function effectively as a semiconductor to amplify or switch electronic signals.
 While cutting graphene sheets into nanoscale ribbons can open up a larger band gap and improve function, 'nanoribbon' devices often have limited driving currents, and practical devices would require the production of dense arrays of ordered nanoribbons — a process that so far has not been achieved or clearly conceptualized.

But Yu Huang, a professor of materials science and engineering at the UCLA Henry Samueli School of Engineering and Applied Science, and her research team, in collaboration with UCLA chemistry professor Xiangfeng Duan, may have found a new solution to the challenges of graphene.

In research to be published in the March issue of Nature Nanotechnology (currently available online), Huang's team reveals the creation of a new graphene nanostructure called graphene nanomesh, or GNM. The new structure is able to open up a band gap in a large sheet of graphene to create a highly uniform, continuous semiconducting thin film that may be processed using standard planar semiconductor processing methods.

"The nanomeshes are prepared by punching a high-density array of nanoscale holes into a single or a few layers of graphene using a self-assembled block copolymer thin film as the mask template," said Huang.

The nanomesh can have variable periodicities, defined as the distance between the centers of two neighboring nanoholes. Neck widths, the shortest distance between the edges of two neighboring holes, can be as low as 5 nanometers.

This ability to control nanomesh periodicity and neck width is very important for controlling electronic properties because charge transport properties are highly dependent on the width and the number of critical current pathways.

Using such nanomesh as the semiconducting channel, Huang and her team have demonstrated room-temperature transistors that can support currents nearly 100 times greater than individual graphene nanoribbon devices, but with a comparable on-off ratio. The on-off ratio is the ratio between the currents when a device is switched on or switched off. This usually reveals how effectively a transistor can be switched off and on.

The researchers have also shown that the on-off ratio can be tuned by varying the neck width.

"GNMs can address many of the critical challenges facing graphene, as well as bypass the most challenging assembly problems," Huang said. "In conjunction with recent advances in the growth of graphene over a large-area substrate, this concept has the potential to enable a uniform, continuous semiconducting nanomesh thin film that can be used to fabricate integrated devices and circuits with desired device size and driving current.

"The concept of the GNM therefore points to a clear pathway towards practical application of graphene as a semiconductor material for future electronics. The unique structural and electronic characteristics of the GNMs may also open up exciting opportunities in highly sensitive biosensors and a new generation of spintronics, from magnetic sensing to storage," she said.

---

Source: PhysOrg.com: http://www.physorg.com/news186397884.html
Provided by University of California - Los Angeles: http://www.ucla.edu/
Nature Nanotechnology Paper Abstract: http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2010.8.html

(NanoRealm) - Huixin He, associate professor, nanoscale chemistry at Rutgers University, Newark, and Tamara Minko, professor at the Rutgers Ernest Mario School of Pharmacy, have developed a nanotechnology approach that potentially could eliminate the problems of side effects and drug resistance in the treatment of cancer. Under traditional chemotherapy, cancer cells, like bacteria, can develop resistance to drug therapy, leading to a relapse of the disease.

As reported in the December 21, 2009, issue of the journal Small, He, Minko and their co-researchers, including investigators from Merck & Co. and Carl Zeiss SMT, a global nanotechnology firm, have designed nanomaterials that allow for the targeted and simultaneous delivery of a chemical drug to destroy cancer cells and a genetic drug to prevent drug resistance.

"We modified the surface of mesoporous silica nanoparticles so that an anticancer drug, doxorubicin, could be loaded into the pores of the silica nanoparticles. Also loaded onto the nanoparticles was a genetic drug designed to prevent or remove multidrug resistance outside the nanoparticles," explained He.

When administered to multidrug-resistant ovarian cancer cells, the nanoparticle treatment was more than 130 times more lethal than when doxorubicin was administrated alone . Most importantly, "the drug can only be released when it is inside the cancer cells. This controlled internal release mechanism can dramatically eliminate side effects associated with anticancer drugs to normal tissues," He noted.

Battling Aggressive Breast Cancer with Nanotubes

In related research, Professor He and another team of co-researchers have developed single-walled carbon nanotubes, consisting of cylinders of carbon about a nanometer in length, that hold the potential of providing a more effective means for detecting and selectively destroying aggressive breast cancer cells.

In a paper published in BMC Cancer late last year, the researchers showed that by chemically bonding a special antibody onto the nanotubes and taking advantage of two unique optical properties of carbon nanotubes (strong Raman scattering and near infrared absorption), single cancer cells can be detected and selectively eradicated while leaving the nearby normal cells unharmed. A uniqueness of this approach is that it offers the advantage of being more easily extended to other types of cancer cells. He's research in the areas of cancer detection and treatment is funded in part with grants from the National Science Foundation and National Cancer Institute.

Research Focuses on Practical Applications Across a Wide Range of Fields

The application of He's nanotechnology research is far and wide. In other research, He and members of her lab at Rutgers are working on the practical application of nanomaterials as a molecular diagnostic tool for Parkinson's disease. Other research is focused on the development of a platform to detect the presence of chemical warfare agents for homeland defense. And in yet other research, He and her lab members are working on nanotechnology to precisely and selectively measure iron ions (Fe3+) in remote ocean atmosphere dust and sea water, which is critical for the study of greenhouse gases and climate change .

At Rutgers, He teaches an undergraduate course in analytical chemistry and graduate courses in electrochemical analytical chemistry and a new course she designed in scanning probe microscopy. She is the recipient of the 2009 Rutgers Presidential Fellowship for Teaching Excellence.

---

For more information: To learn more about He's research, visit http://andromeda.rutgers.edu/~huixinhe/huixinhe.html.

Source: Physorg.com - http://www.physorg.com/news186338960.html
Provided by Rutgers University (web)

(NanoRealm) - Telecommunications researchers in Japan are attempting to create electronic sensors that can not only receive information from the brain, but could manipulate our neural pathways.

While the concept might conjure science-fiction images of half-human, half-machine cyborgs, Dr Keiichi Torimitsu of Nippon Telegraph and Telephone (NTT), says the research is more likely to provide relief for people with Parkinson's disease or overcoming stroke.

Torimitsu presented his team's work on the development of bionic, or bio-mimetic, brain sensors at this week's International Conference on Nanoscience and Nanotechnology (ICONN) in Sydney.

"Establishing connections between the brain and electrical instruments is important for understanding how the brain works and for controlling neural activity," says Torimitsu, who heads NTT's Molecular and Bioscience Group.

"To develop some kind of devices or interfaces with the brain that would make it possible to transmit our information, sending it through the telecommunication pathways to another person or device such as a computer - that is the goal."

A neural interface would be a significant achievement in the rapidly advancing realm of bionic technology, which includes devices such as the cochlear ear implant.

Nano-connections

Torimitsu is working on creating a nano-scaled implant comprising a nano-electrode coated with an artificial membrane that mimics the receptor proteins found on the surface of brain cells, such as glutamate and GABA receptors -involved in increasing and inhibiting brain activity.

Interactions between the receptors and neurotransmitters naturally generate electrical activity. Carefully placed nano-electrodes receive the neurotransmissions providing an instant, accurate electrical reflection of what is occurring, which can be read by an external device.

Torimitsu hopes it would not only monitor activity, but also interact in the connections between neurons known as the synapses.

Ideally, he says, the device would use a biological energy source such as glucose.

"If we could use those proteins on a nano-electrode to generate electrical responses, we could achieve the bio-mimicry of responses."

Torimitsu admits there are a number of hurdles to overcome such as adverse immune responses and possible faults with the machinery. He says at this stage it's unlikely that healthy people would volunteer to have the devices implanted.

But, Torimitsu says it has great medical potential for stroke sufferers and people with Parkinson's disease where brain activity could be controlled.

Australian connections

The Japanese team is working with several researchers in Australia to refine the concept and devise applications for the technology.

Torimitsu has been working with Dr Simon Koblar of the University of Adelaide's Centre for Molecular Genetics of Development, looking at how to apply the technology for the treatment of stroke sufferers.

He is also about to commence working with the University of Wollongong's Intelligent Polymer Research Institute, which works at the forefront of bionics.

Director of the Institute, Professor Gordon Wallace, says one of the goals is to improve the interface with cochlear implant.

He says Torimitsu's work - a meeting of telecommunications technology and biological knowledge - shows why it makes it a very exciting time to be doing such research.

"People are starting to realise all around the world that there are lots of tools that we can use that we already have at our disposal to make this field progress very quickly," says Wallace.

---

Source: ABC News (http://www.abc.net.au/science/articles/2010/02/25/2830261.htm)

(NanoRealm) - Iranian Engineers suggested a new method for lining internal surfaces of pipes, steel and aluminum tubes and bars to fight against common erosions and corrosions.

"First, the surface of aluminum metal was coated by nickel through mechanical alloying (MA) method. To do so, nickel powder together with aluminum samples of cubic form were ball-milled in a planetary ball-mill for various durations and different amounts of the powder.

Such different operational conditions led triggered chemical/diffusional interactions, alloying and formation of new intermetallic phases," Rasoul Pouriamanesh, a member of the research team at Ferdowsi University of Mashhad (FUM) said to the Iran Nanotechnology Initiative Council, elaborating on the steps of the research.

Noting that intermetallic phases like Ni-Al, Al3Ni and Ni3Al were formed inside the coating layer, Pouriamanesh reiterated that it was revealed that the reactions involved (all of which are exothermic) caused local temperature increases and promoted a better cling of layer to target at the spots where the reactions occurred.

"The coating layers were consisted of nanoparticles with different size distributions. After annealing, the microstructures and sizes of the particles were investigated to find the optimal conditions for obtaining perfect coated metal surfaces," he added.

Pouriamanesh referred to "achieving a homogeneous, poreless and uniform nanostructure inside the coating layer (which facilitates metal diffusions and formation of intermetallic phases of Al-Ni" as the outcome of the research.

---

Source: FarNews - http://english.farsnews.com/newstext.php?nn=8812030880

(NanoRealm) - When nanoparticles from consumer products leach into the ocean, they may harm oysters and mussels.

Nanoparticles May Harm Ocean Living Creatures

Manufactured nanomaterials can be found in such diverse applications as electronics, cosmetics, paints, and even medicines, but their effects on the environment remain largely unknown. In a new laboratory study, scientists have found that saltwater oysters and mussels take up and retain significant amounts of manufactured nanoparticles from seawater in clumps of so-called “marine snow.”

“Nanomaterials are being used in increasing amounts, and it’s likely they’re being released in increasing amounts into the environment, including the ocean,” says Evan Ward, professor of marine sciences at UConn’s Avery Point campus. “As we develop these technologies, we need to be cautious, we need to know where the particles are going, and we need to know how they affect marine organisms.”

Nanoparticles are tiny versions of common materials that have a diameter of less than 100 nanometers, or about four millionths of an inch. Their tininess gives them properties that normal-sized particles don’t have: for example, their large surface area for their size makes them stronger, lighter, and more reflective, making them ideal for reinforcing metals, increasing the SPF in your sunscreen, and producing paint that improves your home’s energy efficiency.
Some scientists, however, are concerned that these very properties could also make manufactured nanoparticles dangerous. When products break down in landfills, nanoparticles can wash away into soils, waterways, and the ocean, potentially creating hazards to animals and plants.
“Some materials that one would assume are safe can in fact cause damage to cells in their ‘nano’ form,” Ward says.

Ward studies the environmental physiology of oysters, mussels, and their relatives, which use their gills as specialized filters to take up food from ocean water. Although nanoparticles themselves are too small to be captured in large amounts, Ward’s study focused on how the bivalves’ feeding ecology affected their rate of uptake.

“In our study, we took into account how nanoparticles are likely to be delivered to the animals in the natural environment,” he says. “We asked, ‘What’s the setting in which they will be exposed to these particles?’”

Materials rarely exist as individual particles in the ocean, says Ward; instead, ocean currents bind up particles and sticky organic matter into aggregates that scientists call “marine snow.” These aggregates then sink to the bottom, where filter feeders like bivalves ingest them.

In their paper, published in Marine Environmental Research, Ward and coauthor Dustin Kach, a former UConn graduate student, used natural seawater to produce marine snow that contained fluorescently labeled polystyrene nanoparticles. They then exposed oysters and mussels collected from the Long Island Sound to this snow-filled seawater.

The researchers found that nanoparticles were taken up in much higher amounts when the bivalves were exposed to marine snow. But they also found that when filtered from marine snow, nanoparticles remained in the bivalves’ bodies for a much longer time than would be expected for non-nutritive materials: up to three days.

Ward suspects that the particles are being treated as food by the animals, and are being taken up into their digestive cells. This could be particularly dangerous, he says, since small nanoparticles can circumvent living cells’ natural defenses.

“Because of their high surface area, manufactured nanoparticles can strip off electrons from other compounds and create free radicals,” he says. “Particles like these can cause havoc in cells.”
Ward sees his work as a first step in understanding the potential issues associated with manufactured nanoparticles. He emphasizes that further work is needed to determine the amounts of manufactured nanoparticles in seawater and their levels of toxicity to living things.

“Right now there are few techniques to identify manufactured nanomaterials in the natural environment because they’re so darn small,” he says. “With these studies, we hope to demonstrate potential problems to keep in step with the use of nanomaterials. Then when techniques are available to sample them in the wild, we’ll be prepared to say whether or not we should be worried.”

---

More information: http://www.elsevier.com/wps/find/journaldescription.cws_home/405865/description#description
Provided by University of Connecticut (web)

Source: http://www.physorg.com/news186058984.html

(NanoRealm) - Montana State University scientists are researching the use of nanomaterials to develop a new way of fighting influenza and other respiratory infections caused by viruses.

If it works in humans the way it does in mice, people will prepare for a respiratory viral assault by inhaling an aerosol spray containing tiny protein cages that will activate an immune response in their lungs. This activated immune state will be good against any respiratory virus and last more than a month. People won't have to wait for scientists to analyze new viruses, develop vaccines against them, then distribute and administer the vaccine.
"It's like having a fire department at your house before the fire. If a fire starts, you don't have to call them and wait for them to arrive. They are already there," said Jim Wiley, assistant research professor in the Department of Veterinary Molecular Biology in MSU's College of Agriculture.

Wiley has been working on the protein cage nanomaterial approach for more than 2 1/2 years. A recent $275,000 grant from the National Institutes of Allergy and Infectious Diseases will allow his research team to continue another two years. The grant was made possible through the American Recovery and Reinvestment Act of 2009.

The hollow protein cages he uses in his research are prepared in MSU's Center for Bio-Inspired Nanomaterials, Wiley said. These protein cages are made by a heat-loving bacterium, and they are similar to one which the Center for Bio-Inspired Nanomaterials recently isolated from a bacterium that thrives in the thermal features of Yellowstone National Park. The cages are hollow spheres that carry nothing on the outside. They are so small that they have to be magnified 50,000 times to be seen under an electron microscope. A human hair is 7,000 to 10,000 times wider than these cages.


The cages alone are enough to set off an immune response in the lungs, Wiley said. If the approach works in humans, people who have prepared their lungs with nanomaterials might sniffle for a couple of days instead of being hospitalized. Rather than missing work for a few days with an influenza infection, they may only need to sleep a few extra hours at night.

"You would be able to prepare an entire population for an imminent respiratory viral infection, like the swine influenza infections that we just experienced," Wiley said.

Wiley and 10 co-authors from MSU, Utah State University and the University of Rochester Medical Center have already published a scientific paper on the nanomaterial approach, which is based upon activating "inducible Bronchus-Associated Lymphoid Tissue," or iBALT, in the lung. This iBALT is a naturally occurring tissue that is made in the lung as part of the normal immune response to an infection. The paper showed that the presence of iBALT accelerated the recovery of infected mice without causing lung damage or other harmful side effects. The acceleration effect of the treatment disappeared gradually after one month. The paper about it ran in the September 2009 edition of PLoS One, an online scientific journal from the Public Library of Science.

MSU co-authors of the paper were Laura Richert, Steve Swain, Ann Harmsen, Mark Jutila and Allen Harmsen in the Department of Veterinary Molecular Biology; Trevor Douglas, Chris Broomell and Mark Young in the Center for Bio-Inspired Nanomaterials. Douglas and Broomell are also in the Department of Chemistry and Biochemistry. Young is also in the Department of Plant Sciences and Plant Pathology.

In the current project, Wiley said he and his team are testing this iBALT-based therapy in animal models, whose response to influenza infection is close to that seen in humans. He doesn't know when this iBALT-based approach will be tested in humans, but said, "It certainly is promising as a treatment right at the moment."

He added that nanomaterials could be generated much faster than vaccines.
Wiley's current research team consists of Richert and four lab technicians: Abby Leary, Rebecca Pulman, Soo Han and Mark McAlpine. Richert is a doctoral student from Idaho.

"I have been excited to work on it," Richert said about the project. "It has been interesting from a non-traditional immunological standpoint."
Wiley said if iBALT-based therapies had been in place last year, people would have been better prepared for H1N1.

"If we had been able to develop a state of immune preparedness in the lungs or a partial activation state in the lungs, we could have at least given people some degree of protection," Wiley said.

MSU Technology Transfer Officer Nick Zelver said MSU has a patent on using protein cages to trigger the rapid production of lymphoid tissue in the lung. The technology could be used to prevent or treat a range of pulmonary diseases including influenza. It might counter bioterrorism threats, such as airborne microbes. The protein cage technology is available for licensing from MSU. To see all MSU technologies available for licensing, go to http://tto.montana.edu/technologies.

---

Source: Montana State University

Adapted from: http://www.nanowerk.com/news/newsid=14948.php

Stanford researcher Yi Cui and his team are re-conceptualizing batteries using nanotechnology

(NanoRealm) - By dipping ordinary paper or fabric in a special ink infused with nanoparticles, Stanford engineer Yi Cui has found a way to cheaply and efficiently manufacture lightweight paper batteries and supercapacitors (which, like batteries, store energy, but by electrostatic rather than chemical means), as well as stretchable, conductive textiles known as "eTextiles" – capable of storing energy while retaining the mechanical properties of ordinary paper or fabric.

While the technology is still new, Cui's team has envisioned numerous functional uses for their inventions. Homes of the future could one day be lined with energy-storing wallpaper. Gadget lovers would be able to charge their portable appliances on the go, simply plugging them into an outlet woven into their T-shirts. Energy textiles might also be used to create moving-display apparel, reactive high-performance sportswear and wearable power for a soldier's battle gear.

The key ingredients in developing these high-tech products are not visible to the human eye. Nanostructures, which can be assembled in patterns that allow them to transport electricity, may provide the solutions to a number of problems encountered with electrical storage devices currently available on the market.

The type of nanoparticle used in the Cui group's experimental devices varies according to the intended function of the product – lithium cobalt oxide is a common compound used for batteries, while single-walled carbon nanotubes, or SWNTs, are used for supercapacitors.

Cui, an assistant professor of materials science and engineering at Stanford, leads a research group that investigates new applications of nanoscale materials. The objective, said Cui, is not only to supply answers to theoretical inquiries but also to pursue projects with practical value. Recently, his team has focused on ways to integrate nanotechnology into the realm of energy development.

"Energy storage is a pretty old research field," said Cui. "Supercapacitors, batteries – those things are old. How do you really make a revolutionary impact in this field? It requires quite a dramatic difference of thinking."

While electrical energy storage devices have come a long way since Alessandro Volta debuted the world's first electrical cell in 1800, the technology is facing yet another revolution. Current methods of manufacturing energy storage devices can be capital intensive and environmentally hazardous, and the end products have noticeable performance constraints – conventional lithium ion batteries have a limited storage capacity and are costly to manufacture, while traditional capacitors provide high power but at the expense of energy storage capacity.


With a little help from new science, the batteries of the future may not look anything like the bulky metal units we've grown accustomed to. Nanotechnology is favored as a remedy both for its economic appeal and its capability to improve energy performance in devices that integrate it. Replacing the carbon (graphite) anodes found in lithium ion batteries with anodes of silicon nanowires, for example, has the potential to increase their storage capacity by 10 times, according to experiments conducted by Cui's team.

Silicon had previously been recognized as a favorable anode material because it can hold a larger amount of lithium than carbon. But applications of silicon were limited by its inability to sustain physical stress – namely, the fourfold volume increase that silicon undergoes when lithium ions attach themselves to a silicon anode in the process of charging a battery, as well as the shrinkage that occurs when lithium ions are drawn out as it discharges. The result was that silicon structures would disintegrate, causing anodes of this material to lose much if not all of their storage capacity.

Cui and collaborators demonstrated in previous publications in Nature, Nanotechnology and Nano Letters that the use of silicon nanowire battery electrodes, mechanically capable of withstanding the absorption and discharge of lithium ions, was one way to sidestep the problem.

The findings hold promise for the development of rechargeable lithium batteries offering a longer life cycle and higher energy capacity than their contemporaries. Silicon nanowire technology may one day find a home in electric cars, portable electronic devices and implantable medical appliances.

Cui now hopes to direct his research toward studying both the "hard science" behind the electrical properties of nanomaterials and designing real-world applications.

"This is the right time to really see what we learn from nanoscience and do practical applications that are extremely promising," said Cui. "The beauty of this is, it combines the lowest cost technology that you can find to the highest tech nanotechnology to produce something great. I think this is a very exciting idea … a huge impact for society."

---

The Cui group's latest research on energy storage devices was detailed in papers published in the online editions of the Proceedings of the National Academy of Sciences in December 2009 ("Highly Conductive Paper for Energy-Storage Devices") and Nano Letters in January 2010 ("Stretchable, Porous and Conductive Energy Textiles").

Cui's talk at the symposium "Nanotechnology: Will Nanomaterials Revolutionize Energy Applications?" is scheduled for 9:50 a.m. Feb. 20 in Room 1B of the San Diego Convention Center.

Video/photos:
Conductive eTextiles: Stanford finds a new use for cloth
http://news.stanford.edu/news/2010/february1/batteries-from-cloth-020510.html

At Stanford, nanotubes + ink + paper = instant battery
http://news.stanford.edu/news/2009/december7/nanotubes-ink-paper-120709.html

Source: http://www.eurekalert.org/pub_releases/2010-02/su-nse021910.php

(NanoRealm) - New research at the A. James Clark School of Engineering could prevent bacterial infections using tiny biochemical machines - nanofactories - that can confuse bacteria and stop them from spreading, without the use of antibiotics.

A paper about the research is featured in the current issue of Nature Nanotechnology. "Engineered biological nanofactories trigger quorum sensing response in targeted bacteria," was authored by Clark School alumnus Rohan Fernandes (Ph.D. '08, bioengineering), graduate student Varnika Roy (molecular and cell biology), graduate student Hsuan-Chen Wu (bioengineering), and their advisor, William Bentley (professor and chair, Fischell Department of Bioengineering).

The group's work is an update on their original nanofactories, first developed in 2007. Those nanofactories made use of tiny magnetic bits to guide them to the infection site.
"This is a completely new, all-biological version," he says. "The new nanofactories are self-guided and targeted. We've demonstrated for the first time that they're capable of finding a specific kind of bacterium and inducing it to communicate, a much finer level of automation and control."

The new nanofactories can tell the difference between bad (pathogenic) and good bacteria. For instance, our digestive tracts contain a certain level of good bacteria to help us digest food. The new nanofactories could target just the bad bacteria, without disrupting the levels of good bacteria in the digestive tract (a common side effect of many antibiotics). Nanofactories target the bacteria directly rather than traveling throughout the body, another advantage over traditional antibiotics.

Bacterial cells talk to each other in a form of cell-to-cell communication known as quorum sensing. When the cells sense that they have reached a certain quantity, an infection could be triggered. The biological nanofactories developed at the Clark School can interrupt this communication, disrupting the actions of the cells and shutting down an infection.

Alternatively, the nanofactories could trick the bacteria into sensing a quorum too early. Doing so would trigger the bacteria to try to form an infection before there are enough bacterial cells to do harm. This would prompt a natural immune system response capable of stopping them without the use of drugs.

Because nanofactories are designed to affect communication instead of trying to kill the bacteria, they could help treat illness in cases where a strain of bacteria has become resistant to antibiotics.

"The work by Dr. Bentley is extremely exciting as he is using the ability of engineering to "build" using nature based components," says Philip Leduc, associate professor in the Departments of Mechanical and Biomedical Engineering and the Lane Center for Computational Biology and Biological Sciences at Carnegie Mellon University. "Understanding the science of cells is wonderful, but then using these components and constructing systems that leverage biological advantages is a huge step forward. His work in this paper uses his synthetic biology approach to build new nanofactories toward new areas of antimicrobials as well as opening new findings in quorum sensing."

The nanofactories' ability to alter cell-to-cell communication isn't limited to fighting infections.

"Quorum sensing and signaling molecules are actually used to accomplish a lot of things," Bentley explains. "Sometimes disease develops because communication is not taking place—a good example is digestive disorders that involve an imbalance of bacteria in the digestive tract. In that case, nanofactories could be used to start or increase communication instead of disrupting it."

---

More information: Paper - Engineered biological nanofactories trigger quorum sensing response in targeted bacteria
Provided by University of Maryland (web)

(NanoRealm)- Welding uses heat to join pieces of metal in everything from circuits to skyscrapers. But Rice University researchers have found a way to beat the heat on the nanoscale.

Jun Lou, an assistant professor in mechanical engineering and materials science, and his group have discovered that gold wires between three-billionths and 10-billionths of a meter wide weld themselves together quite nicely – without heat.

They report in today's online edition of the journal Nature Nanotechnology that clean gold nanowires with identical atomic structures will merge into a single wire that loses none of its electrical and mechanical properties. The process works just as well with silver nanowires, which bond with each other or with gold.

This cold-welding process has been observed on the macro scale for decades, Lou said. Clean, flat pieces of similar metals can be made to bond under high pressure and in a vacuum. But only Lou and his colleagues have seen the process happen on the nanoscale, under an electron microscope.

As so often happens in basic research, that's not what they were looking for at all. Lou and Rice graduate student Yang Lu, with collaborators at Sandia National Laboratories and Brown University, were trying to determine the tensile strength of gold nanowires by attaching one end of a wire to a probe in a transmission electron microscope (TEM) and the other to a tiny cantilever spring called an atomic force microscopy (AFM) probe.

Pulling the wire apart gave the team a measurement of its strength. What they didn't expect to see was the broken wire mending itself when its ends or sides touched. Measurements showed the reconnected wire was as strong as before.

"Before you can actually stretch something, you need to clamp it well," said Lou, who received a Young Investigators Research Program grant from the Air Force Office of Sponsored Research last year. "During the manipulation process, we observed this type of welding behavior all the time.

"Initially, we didn't pay attention to it because it didn't seem significant. But after doing a little research on the field, I realized we discovered something that may be useful."

In testing, Lou found the nanowires could be snapped and welded many times. Mended wires never broke again at the same spot; this attests to the strength of the new bond.

The wire's electrical properties also seemed unaffected by repeated breaking and welding. "We'd break a wire and reweld it 11 times and check the electrical properties every time. All the numbers were very close," he said.

The keys to a successful weld are the nanowire's single crystalline structure and matching orientation. "There are a lot of surface atoms, very active, that participate in the diffusion at the nanoscale," Lou said. "We tried gold and silver, and they weld in the same way as long as you satisfy the crystalline-orientation requirement."

Lou sees the discovery opening new paths for researchers looking at molecular-scale electronics. He said teams at Harvard and Northwestern are working on ways to pattern arrays of nanowires, and incorporating cold welding could simplify their processes. "If you're building high-density electronic devices, these kinds of phenomena will be very useful," he said, noting that heat-induced welds on the nanoscale run the risk of damaging the materials' strength or conductivity.

Lou said the discovery has caused a stir among the few he's told. "Different people see different aspects: Electrical engineers see the application side. Theory people see some interesting physics behind this behavior. We hope this paper will encourage more fundamental study."

---

The paper's co-authors include Jian Yu Huang, a scientist at the Center for Integrated Nanotechnologies at Sandia National Laboratories; and Professor Shouheng Sun and former graduate student Chao Wang of Brown University.

The National Science Foundation and the Air Force Office of Sponsored Research supported the project.

---

Source: Rice University (web)

Paper: "Cold welding of ultrathin gold nanowires" by Yang Lu, Jian Yu Huang, Chao Wang, Shouheng Sun & Jun Lou

(NanoRealm) - One of the difficulties of fighting cancer is that drugs often hit other non-cancerous cells, causing patients to get sick. But what if researchers could sneak cancer-fighting particles into just the cancer cells? Researchers at the Georgia Institute of Technology and the Ovarian Cancer Institute are working on doing just that. In the online journal BMC Cancer they detail a method that uses hydrogels - less than 100 nanometers in size - to sneak a particular type of small interfering RNA(siRNA) into cancer cells. Once in the cell the siRNA turns on the programmed cell death the body uses to kill mutated cells and help traditional chemotherapy do it’s job.

Many cancers are characterized by an over abundance of epidermal growth factor receptors (EGFR). When the EGFR level in a cell is elevated it tells the cell to replicate at a rapid rate. It also turns down apoptosis, or programmed cell death.

“With our technique we’re inhibiting EGFR’s growth, with small interfering RNA. And by inhibiting it’s growth, we’re increasing the cells’s apoptotic function. If we hit the cell with chemotherapy at the same time, we should be able to kill the cancer cells more effectively,” said John McDonald, professor at the School of Biology at Georgia Tech and chief research scientist at the Ovarian Cancer Institute.

Small interfering RNA is good at shutting down EGFR production, but once inside the cell siRNA has a limited life span. Keeping it protected inside the hydrogel nanoparticles allows them to get into the cancer cell safely and acts as a protective barrier around them. The hydrogel releases only a small amount of siRNA at a time, ensuring that while some are out in the cancer cell doing their job, reinforcements are held safely inside the nanoparticle until it’s time to do their job.

“It’s like a Trojan horse,” said L. Andrew Lyon, professor in the School of Chemistry and Biochemistry at Georgia Tech. “We’ve decorated the surface of these hydrogels with a ligand that tricks the cancer cell into taking it up. Once inside, the particles have a slow release profile that leaks out the siRNA over a timescale of days, allowing it to have a therapeutic effect.”

Cells use the messenger RNA (mRNA) to generate proteins, which help to keep the cell growing. Once the siRNA enters the cell, it binds to the mRNA and recruits proteins that attack the siRNA-mRNA complex. But the cancer cell's not finished; it keeps generating proteins, so without a continuous supply of siRNA, the cell recovers. Using the hydrogel to slowly release the siRNA allows it to keep up a sustained attack so that it can continue to interrupt the production of proteins.

“We’ve shown that you can get knock down out to a few days time frame, which could present a clinical window to come in and do multiple treatments in a combination chemotherapy approach,” said Lyon.

“The fact that this system is releasing the siRNA slowly, without giving the cell time to immediately recover, gives us much better efficiency at killing the cancer cells with chemotherapy,” added McDonald.

Previous techniques have involved using antibodies to knock down the proteins.
“But oftentimes, a mutation may arise in the targeted gene such that the antibody will no longer have the effect it once did, thereby increasing the chance for recurrence,” said McDonald.

The team used hydrogels because they’re non-toxic, have a relatively slow release rate, and can survive in the body long enough to reach their target.

“It’s a well-defined architecture that you’re using the intrinsic porosity of that material to load things into, and since our particles are about 98 percent water by volume, there’s plenty of internal volume in which to load things,” said Lyon.

Currently, the tests have been shown to work in vitro, but the team will be initiating tests in vivo shortly.

---

Provided by Georgia Institute of Technology

The Georgia Institute of Technology is one of the nation's premier research universities. Ranked seventh among U.S. News & World Report's top public universities, Georgia Tech's more than 20,000 students are enrolled in its Colleges of Architecture, Computing, Engineering, Liberal Arts, Management and Sciences. Tech is among the nation's top producers of women and minority engineers. The Institute offers research opportunities to both undergraduate and graduate students and is home to more than 100 interdisciplinary units plus the Georgia Tech Research Institute.

---

Source: PhyOrg.com (web)

(NanoRealm) - A tiny scaffold-like titanium structure of Nanonets coated with silicon particles could pave the way for faster, lighter and longer-lasting Lithium-ion batteries, according to a team of Boston College chemists who developed the new anode material using nanotechnology.

The web-like Nanonets developed in the lab of Assistant Professor of Chemistry Dunwei Wang offer a unique structural strength, more surface area and greater conductivity, which produced a charge/re-charge rate five to 10 times greater than typical Lithium-ion anode material, a common component in batteries for a range of consumer electronics, according to findings published in the current online edition of the American Chemical Society journal Nano Letters.

In addition, the Nanonets proved exceptionally durable, showing a negligible drop-off in capacity during charge and re-charge cycles. The researchers observed an average of 0.1% capacity fade per cycle between the 20th and the 100th cycles.

"As researchers pursue the next generation of re-chargeable Lithium-ion battery technology, a premium has been placed on increased power and a greater battery life span," said Wang. "In that context, the Nanonet device makes a giant leap toward those two goals and gives us a superior anode material."

Lithium-ion batteries are commonly used in consumer electronics devices. This type of rechargeable battery allows Lithium ions to move from the anode electrode to the cathode when in use. When charged, the ions move from cathode back to the anode.

The structure and conductivity of the Nanonets improved the ability to insert and extract Lithium ions from the particulate silicon coating, the team reported. Running at a charge/discharge rate of 8,400 milliamps per gram (mA/g) - which is approximately five to 10 times greater than similar devices - the specific capacity of the material was greater than 1,000 milliamps-hour per gram (mA-h/g). Typically, laptop Lithium-ion batteries are rated anywhere between 4,000 and 12,000 mA/h, meaning it would only take between four and 12 grams of the Nanonet anode material to achieve similar capacity.

Wang said the capability to preserve the crystalline titanium silicon core during the charge/discharge process was the key to achieving the high performance of the Nanonet anode material. Additional research in his lab will examine the performance of the Nanonet as a cathode material.

---

News adapted from PhyOrg.com

More information: View the Nano Letters paper at http://pubs.acs.org/doi/abs/10.1021/nl903345f

Provided by Boston College (web)

(NanoRealm)- The world's first "power suit" seems closer to reality now. Scientists have come up with new fiber nanogenerators which may help design the very first one.

Researchers at University of California, Berkeley, developed the energy-scavenging nanofibers that can convert energy created through mechanical stress, stretches and twists into electricity, furthering hope of creating clothing that can power small electronics.

Liwei Lin, UC Berkeley professor of mechanical engineering and head of the international research team that developed the fiber nanogenerators, said: "This technology could eventually lead to wearable 'smart clothes' that can power hand-held electronics through ordinary body movements."

Lin, also co-director of the Berkeley Sensor and Actuator Center at UC Berkeley, added: "And because the nanofibers are so small, we could weave them right into clothes with no perceptible change in comfort for the user."

Chieh Chang, the study's lead author, who conducted the experiments while he was a graduate student in mechanical engineering at UC Berkeley, explained: "Surprisingly, the energy efficiency ratings of the nanofibers are much greater than the 0.5 to 4 percent achieved in typical power generators made from experimental piezoelectric PVDF thin films, and the 6.8 percent in nanogenerators made from zinc oxide fine wires."

Lin continued: "We think the efficiency likely could be raised further. For our preliminary results, we see a trend that the smaller the fiber we have, the better the energy efficiency. We don't know what the limit is."

Other co-authors of the study were Yiin-Kuen Fuh, a UC Berkeley graduate student in mechanical engineering; Van H. Tran, a graduate student at the Technische Universitat Munchen (Technical University of Munich) in Germany; and Junbo Wang, a researcher at the Institute of Electronics at the Chinese Academy of Sciences in Beijing, China.

The fiber nanogenerators were described in the Nano Letters, a peer-reviewed journal published by the American Chemical Society.

---

Source-ANI

News from: MedIndia - (web)

(NanoRealm) - Researchers move one step closer to nature with the development of polymers and directional adhesion that follow the workings of a gecko's foot

Nanotechnology has not only brought nature and engineering closer together; it has encouraged collaboration among researchers of different disciplines. In one such collaboration, two researchers drew on the extraordinary stickiness of a gecko's foot to develop a synthetic adhesive to help robots scale walls.

NSF-funded researchers Mark Cutkosky, an engineer at Stanford University, and Kellar Autumn, a biologist at Lewis and Clark College, have collaborated to develop a gecko-like synthetic adhesive that functions like real gecko bristles for climbing applications. The team discovered the fundamental physics principles underlying gecko adhesion, which enabled the invention of an adhesive nanostructure.

The Tokay gecko, one of the largest and heaviest geckos, served as inspiration.

"The challenge was simply to get robots to go where robots have never been able to go before, like up walls of buildings," said Cutkosky. "If robots can climb vertical surfaces, then they can do inspection of buildings and bridges and other hard- to-reach places."

Cutkosky received a four-year, $1 million National Science Foundation research grant that funded the development of the first gecko-like synthetic adhesive (GSA) that works like real gecko bristles. Autumn received two NSF grants for continued research on gecko adhesion. Cutkosky's team collaborated with Kellar Autumn and his gecko lab to determine whether a synthetic adhesive could be applied to robots.

"The collaboration with Mark's group has been incredibly productive. Based on micro-force measurements, we hypothesized that a coupling of shear force and adhesion was responsible for control of the geckos' attachment system," said Autumn.

A gecko's foot possesses a sophisticated adhesion system that uses van der Waals forces, which are the basic molecular attraction that exists between molecules. Van der Waals forces allow geckos to climb and hang on a smooth and vertical surfaces using one toe.

Cutkosky and his team have been designing bio-inspired robots which use van der Waals forces. Their most recent design is stickybot, a robot that has gecko-like pads, which allows it to scale walls and buildings.

Bio-inspired design on a nano scale

The intricate work of nature occurs on a tiny scale, below the limits of our vision. Beneath the surface of a gecko's foot is a three-level hierarchy of structures. The first level is made up of lamellae, which are a series of structures that look like flaps under a microscope. Then, the lamellae are divided into smaller structures called seate which are thinner than a human hair. Finally, the seate branch into tiny little ends called spatulae, which are only a couple of hundred nanometers in size.

"So what happens is that the gecko is able to conform to surfaces ranging from tens or hundreds of nanometers all the way up to centimeters," said Cutkosky. "It is very cool; it is sort of the poster child for complex hierarchical geometry, almost fractal in its nature."

The structures that compose the different levels in the hierarchy have a similar behavior at multiple length scales.

The gecko's toe structures are only adhesive when loaded in a particular direction and the gecko can control adhesion by aligning its microstructures and making intimate contact with the surface. Stickybot follows the same principles as a gecko, but needs to adjust the orientation of its feet as it climbs. This is to ensure that the toes are always loaded in the proper direction for adhesion.

Cutkosky and Autumn have built similar synthetic structures that follow the design of a gecko's foot. At present, they have created a two layer hierarchy of polymers with directional adhesion. This is good enough for stickybot to use to scale walls; however there is always room for improvement.

"It comes down to how much adhesion you are getting per unit area. The gecko can easily support its weight on one toe. In fact, it has lots to spare. Without the latest and greatest adhesives, I think stickybot can barely support its weight on one toe. We are nowhere near the gecko. Basically, it comes down to the weight of the robot and how many pascals of adhesion you can get from your material," said Cutkosky.



The pascal is a measurement of force per unit area which allows researchers, like Cutkosky, to determine how much stress the synthetic adhesion can tolerate. This helps gauge how the adhesive is developed and how it can be changed in the future.

The future of stickybot

Stickybot employs three main principles to climb smooth surfaces: hierarchical compliance to conform to levels from micrometers to centimeters, directional adhesion to smoothly engage and disengage from a surface, and force control to control frictional forces in the feet. Though stickybot can climb on vertical and smooth surfaces, Cutkosky hopes to develop a robot capable of climbing a wide variety of surfaces.

"We are continuing to try and improve the dry adhesive itself, but independent from that; we are working on a new stickybot. Making the ankles of the robot rotate is probably number one, but we also want to do more sensing and control. Right now stickybot doesn't have many sensors, so if it's climbing and starting to get into trouble, it doesn't know that and may fall," said Cutkosky.


Cutkosky and Autumn's research and collaboration have shown how materials science is attempting to follow nature.

"Nature has a huge advantage it can grow and differentiate cell by cell. Whereas, when we manufacture things we're always using processes that work top-down and so every layer is difficult and expensive for us," said Cutkosky.

---

Sources:

• National Science Foundation
  
• Stanford
  
• Gecko Lab Lewis and Clark
  

Arizona State University scientists have come up with a new twist in their efforts to develop a faster and cheaper way to read the DNA genetic code. They have developed the first, versatile DNA reader that can discriminate between DNA's four core chemical components⎯the key to unlocking the vital code behind human heredity and health.

Led by ASU Regents' Professor Stuart Lindsay, director of the Biodesign Institute's Center for Single Molecule Biophysics, the ASU team is one of a handful that has received stimulus funds for a National Human Genome Research Initiative, part of the National Institutes of Health, to make DNA genome sequencing as widespread as a routine medical checkup.

The broad goal of this "$1000 genome" initiative is to develop a next-generation DNA sequencing technology to usher in the age of personalized medicine, where knowledge of an individual's complete, 3 billion-long code of DNA information, or genome, will allow for a more tailored approach to disease diagnosis and treatment. With current technologies taking almost a year to complete at a cost of several hundreds of thousands of dollars, less than 20 individuals on the planet have had their whole genomes sequenced to date.

To make their research dream a reality, Lindsay's team has envisioned building a tiny, nanoscale DNA reader that could work like a supermarket checkout scanner, distinguishing between the four chemical letters of the DNA genetic code, abbreviated by A, G, C, and T, as they rapidly pass by the reader. To do so, they needed to develop the nanotechnology equivalent of threading the eye of a needle. In this case, the DNA would be the thread that could be recognized as it moved past the reader 'eye.' During the past few years, Lindsay's team has made steady progress, and first demonstrated the ability to read individual DNA sequences in 2008 -- but this approach was limited because they had to use four separate readers to recognize each of the DNA bases. More recently, they demonstrated the ability to thread DNA sequences through the narrow hole of a fundamental building block of nanotechnology, the carbon nanotube.

Lindsay's team relies on the eyes of nanotechnology, scanning tunneling- (STM) and atomic force- (ATM) microscopes, to make their measurements. The microscopes have a delicate electrode tip that is held very close to the DNA sample. In their latest innovation, Lindsay's team made two electrodes, one on the end of microscope probe, and another on the surface, that had their tiny ends chemically modified to attract and catch the DNA between a gap like a pair of chemical tweezers. The gap between these functionalized electrodes had to be adjusted to find the chemical bonding sweet spot, so that when a single chemical base of DNA passed through a tiny, 2.5 nanometer gap between two gold electrodes, it momentarily sticks to the electrodes and a small increase in the current is detected. Any smaller, and the molecules would be able to bind in many configurations, confusing the readout, any bigger and smaller bases would not be detected.


"What we did was to narrow the number of types of bound configurations to just one per DNA base," said Lindsay. "The beauty of the approach is that all the four bases just fit the 2.5 nanometer gap, so it is one size fits all, but only just so!"

At this scale, which is just a few atomic diameters wide, quantum phenomena are at play where the electrons can actually leak from one electrode to the other, tunneling through the DNA bases in the process. Each of the chemical bases of the DNA genetic code, abbreviated A, C, T or G, gives a unique electrical signature as they pass between the gap in the electrodes. By trial and error, and a bit of serendipity, they discovered that just a single chemical modification to both electrodes could distinguish between all 4 DNA bases.

"We've now made a generic DNA sequence reader and are the first group to report the detection of all 4 DNA bases in one tunnel gap," said Lindsay. "Also, the control experiments show that there is a certain (poor) level of discrimination with even bare electrodes (the control experiments) and this is in itself, a first too."

"We were quite surprised about binding to bare electrodes because, like many physicists, we had always assumed that the bases would just tumble through. But actually, any surface chemist will tell you that the bases have weak chemical interactions with metal surfaces."

Next, Lindsay's group is hard at work trying to adapt the reader to work in water-based solutions, a critically practical step for DNA sequencing applications. Also, the team would like to combine the reader capabilities with the carbon nanotube technology to work on reading short stretches of DNA.

If the process can be perfected, DNA sequencing could be performed much faster than current technology, and at a fraction of the cost. Only then will the promise of personalized medicine reach a mass audience.

The authors on the Nano Letters paper are: Shuai Chang, Shuo Huang, Jin He, Feng Liang, Peiming Zhang, Shengqing Li, Xiang Chen, Otto Sankey and Stuart Lindsay

Adapted from materials provided by Arizona State University, via EurekAlert!, a service of AAAS.

---

1. Chang et al. Electronic Signatures of all Four DNA Nucleosides in a Tunneling Gap. Nano Letters, 2010; 100208153708084 DOI: 10.1021/nl1001185

Material scientists at the Nano/Bio Interface Center of theUniversity of Pennsylvania have demonstrated the transduction of optical radiation to electrical current in a molecular circuit. The system, an array of nano-sized molecules of gold, respond to electromagnetic waves by creating surface plasmons that induce and project electrical current across molecules, similar to that of photovoltaic solar cells.

The results may provide a technological approach for higher efficiency energy harvesting with a nano-sized circuit that can power itself, potentially through sunlight. Recently, surface plasmons have been engineered into a variety of light-activated devices such as biosensors.

It is also possible that the system could be used for computer data storage. While the traditional computer processor represents data in binary form, either on or off, a computer that used such photovoltaic circuits could store data corresponding to wavelengths of light.

Because molecular compounds exhibit a wide range of optical and electrical properties, the strategies for fabrication, testing and analysis elucidated in this study can form the basis of a new set of devices in which plasmon-controlled electrical properties of single molecules could be designed with wide implications to plasmonic circuits and optoelectronic and energy-harvesting devices.

Dawn Bonnell, a professor of materials science and the director of the Nano/Bio Interface Center at Penn, and colleagues fabricated an array of light sensitive, gold nanoparticles, linking them on a glass substrate. Minimizing the space between the nanoparticles to an optimal distance, researchers used optical radiation to excite conductive electrons, called plasmons, to ride the surface of the gold nanoparticles and focus light to the junction where the molecules are connected. The plasmon effect increases the efficiency of current production in the molecule by a factor of 400 to 2000 percent, which can then be transported through the network to the outside world.


In the case where the optical radiation excites a surface plasmon and the nanoparticles are optimally coupled, a large electromagnetic field is established between the particles and captured by gold nanoparticles. The particles then couple to one another, forming a percolative path across opposing electrodes. The size, shape and separation can be tailored to engineer the region of focused light. When the size, shape and separation of the particles are optimized to produce a “resonant” optical antennae, enhancement factors of thousands
might result.

Furthermore, the team demonstrated that the magnitude of the photoconductivity of the plasmon-coupled nanoparticles can be tuned independently of the optical characteristics of the molecule, a result that has significant implications for future nanoscale optoelectronic devices.

“If the efficiency of the system could be scaled up without any additional, unforeseen limitations, we could conceivably manufacture a one-amp, one-volt sample the diameter of a human hair and an inch long," Bonnell said.

The study, published in the current issue of the journal ACS Nano, was conducted by Bonnell, David Conklin and Sanjini Nanayakkara of the Department of Materials Science and Engineering in the School of Engineering and Applied Science at Penn; Tae-Hong Park of the Department of Chemistry in the School of Arts and Sceicnes at Penn; Parag Banerjee of the Department of Materials Science and Engineering at the University of Maryland; and Michael J. Therien of the Department of Chemistry at Duke University.

This work was supported by the Nano/Bio Interface Center, National Science Foundation, the John and Maureen Hendricks Energy Fellowship and the U.S. Department of Energy.

---

Source: University of Pennsylvania(web)

(NanoRealm)- University of Florida scientists have developed a new nanoparticle that could improve cancer detection and drug delivery. The particle, called a “micelle” and made up of a cluster of molecules called aptamers, easily recognizes tumors and binds strongly to them. It also has properties that allow it to easily get inside cells for intracellular studies and drug delivery.

“That is important, because we could attach a drug to the aptamer so that the drug could get into a cell,” said Yanrong Wu, who recently completed her doctoral research at UF. Wu was the first author of a paper describing the findings in January in the Proceedings of the National Academy of Sciences entitle "DNA aptamer–micelle as an efficient detection/delivery vehicle toward cancer cells".


In allowing more targeted treatment of diseased cells, the micelles would help reduce damage to healthy cells even with large doses of chemotherapy. Current methods often destroy normal cells while trying to kill tumor cells.

In biological studies, molecules termed “probes” have properties that enable them to detect other molecules or organisms of interest, such as viruses. Compared with existing probes such as antibodies, the aptamers offer advantages in terms of ease of production and identification, faster response time and much lower molecular weight.

Aptamers, the building blocks of the micelles, are short single strands of DNA that can recognize other molecules based on certain chemical conformation.

In previous drug delivery tests, aptamers on their own could only attach limited drug molecules and sometimes could not effectively recognize tumor cells, so UF researchers re-engineered the molecule to improve its usefulness in biomedical studies in the watery environment inside the body.

They effectively turned the aptamer molecules into a molecular recognition and drug delivery system combination that escorts water-insoluble compounds such as drugs into cells by encapsulating them inside a water-soluble structure.

To do so, the team, led by Weihong Tan, the V.T. and Louise Jackson professor of chemistry at the College of Liberal Arts and Sciences and a professor of physiology and functional genomics in the UF College of Medicine, attached a “water-hating” — or hydrophobic — tail to the aptamers. The new molecules cluster together to form a micelle by tucking their water-hating tails together, exposing only the “water-loving” — or hydrophilic — portion of the structure. In that way, the micelle can shield water-insoluble agents such as drugs within its center, and help usher them into cells.

“It was kind of a stealth situation where the cell sees only the hydrophilic part, but inside, the drug is in the hydrophobic part,” said Nick Turro, the William P. Schweitzer professor of chemistry at Columbia University, who was not involved in the study. “This opens a number of avenues that were unavailable before.”
In tests that mimic physiological conditions, the micelles were more sensitive than the molecular probes alone. The micelle bound more strongly to target cells. That could lead to easier and earlier detection of biomarkers of disease such as cancer.

“When you are talking about diagnosis, these aptamers in micelles will have a much higher signal than individual aptamers, so we may be able to detect very small amounts of the substance we’re testing for,” said Tan, also a member of the UF Genetics Institute, the UF Shands Cancer Center and the Moffitt Cancer Center and Research Institute.

The micelle structures also might prove useful to more accurately determine how much diseased tissue is left behind after chemotherapy or surgery.

Now that the researchers have demonstrated the micelle’s ability to bind in simulated physiological conditions, the next step will be to test it in real tumors.

The National Institutes of Health and The Florida Biomedical Research Program supported the research. Other investigators include Haipeng Liu, Kwame Sefah and Ruowen Wang.

---

Source: University of Florida (news)

World Gold Council Research Paper Demonstrates Important Applications in Development Using Gold Nanoparticles

World Gold Council (WGC) has today published 'Gold for Good: Gold and nanotechnology in the age of innovation', a research paper detailing new scientific and technological innovations using gold. The report, which was produced in conjunction with Cientifica Ltd, the world's leading source of global business and investor intelligence about nanotechnologies, demonstrates how gold nanoparticles offer the potential to overcome many of the serious issues facing mankind over the coming decades.

Gold nanoparticles exhibit a variety of unique properties which, when harnessed and manipulated effectively, lead to materials whose uses are both far-ranging in their potential and cost effective. This report explores the many different applications that are being developed across the fields of health, environment and technology.

Trevor Keel, Nanotechnology Project Manager at World Gold Council said:
"The opportunities and possibilities identified in this report are just a subset of the amazing scope to use gold in the era of nanotechnology. As a readily available and well understood material, gold nanoparticles are ideal for use in a vast array of applications that improve our lives. WGC is looking to promote and invest in the development of gold-based innovations through Innovations Partnerships, so that the full benefits of gold nanotechnology can be realized."


Tim Harper, founder of Cientifica Ltd, said:
"Over the last decade, almost $50 billion of government funding has been invested into nanotechnologies, and this investment is now starting to bear fruit with a steady stream of commercially viable nanotechnologies which are positively impacting human health, the environment and technology. This paper demonstrates the many varied applications in which gold nanotechnology can improve society's standard of living."

Health: 
Gold has a long history in the biomedical field stretching back almost five thousand years. However the dawn of the 'nano-age' has really broadened the potential of gold in biomedical applications and today, gold nanoparticles are being employed in entirely novel ways to achieve therapeutic effects.

Tumor targeting technologies which exploit gold's inherent bio-compatibility are being developed to deliver drugs directly into cancerous tumours. Additionally, simple, cost effective and sensitive diagnostic tests are being developed for the early detection of prostate and other cancers.

Environment: 
Environmental concerns have never been more prominent - energy and clean water scarcity, global warming and pollution are all major issues that need to be addressed. Gold nano-particle based technologies are showing great promise in providing solutions to a number of environmentally important issues from greener production methods of the chemical feedstocks, to pollution control and water purification.

Gold-based catalysts are being developed that can effectively prevent the release of highly toxic forms of mercury into the atmosphere, the reduction of chemicals from green feedstock, and also for water purification and contaminant detection. In addition, gold is being used in meeting the challenge of constructing cost effective and efficient fuel cells, a key 'clean-energy' technology of the future.


Advanced technology: 
Gold is already a well established material in the electronics industry and the use of gold can only increase as the worlds of electronics and nanotechnology interact further in the future. Gold is being developed for conductive nanoparticle inks for plastic electronics because of its material compatibility, inherent durability and proven track record of reliability. Gold nanotechnologies have also been shown to offer functional benefits for visual display technologies like touch sensitive screens and potentially for use in advanced data storage technologies including advanced flash memory devices.

The full paper can be downloaded from:
http://www.gold.org/assets/file/rs_archive/gold_and_nanotechnology_in_the_age_of_innovation.pdf
(Due to the length of this URL, it may be necessary to copy and paste this hyperlink into your Internet browser's URL address field. Remove the space if one exists.)

http://cientifica.eu/blog/white-papers/gold/

---

Innovation Partnerships
World Gold Council works directly with partner companies via Innovation Partnerships. These support research and development of new practical applications for the metal, drawing on a genuine commercial market requirement for innovation. Partner organisations include (but are not limited to) precious metal, chemical, electronics, materials and biomedical companies, ranging from small enterprises through to established international businesses. Interested companies are invited to contact World Gold Council for further details.

During 2009-2010 World Gold Council is particularly interested in receiving proposals relating to the following areas:

• Industrial catalysts (including catalysts for pollution control and chemical processing)
  
• Biomedical applications (including medical diagnostics, therapeutics and materials)
  
• Advanced electronics (including any technology or component likely to be used in next-generation devices)
  
• Fuel cell systems (including applications both within the fuel cell structure and hydrogen processing infrastructure)
  
• Optical materials (including nanotechnology, chemicals and coatings)

Companies interested in collaborating with World Gold Council are invited to make contact.

---

Notes to Editors:
World Gold Council
World Gold Council's mission is to stimulate and sustain the demand for gold and to create enduring value for its stakeholders. It is funded by the world's leading gold mining companies. For further information please visit http://www.gold.org.

Cientifica
Cientifica Ltd, based in London, is one of the world's best-respected consultancy companies in the field of emerging technologies and technology commercialization. It provides global business intelligence and strategic consulting services to industry, governments and investors worldwide.
http://www.cientifica.eu