(NanoRealm) - While scientists have become rather adept at transforming generic skin cells into specialized organ cells, crafting the organs themselves has proven far more difficult. Since the 3-D architecture of most organs is as important to their function as their cellular makeup, 2-D cell cultures are not very useful for building a replacement heart from scratch. To solve that problem, most organ makers create a scaffolding for the cells to grow on.

For a team of researchers at Rice University, even a biodegradable scaffolding wasn't good enough. By injecting cells with a metallic gel, the researchers have succeeded in suspending cultured cells in a three-dimensional magnetic field. With this magnetic scaffolding, organs can be grown in the right shape, and with no foreign material.

The researchers used bacteriophages, special viruses that inject themselves into cells, to insert a polymer iron oxide gel into brain cancer cells. Once the cells absorbed the magnetic gel, the Rice scientists levitated the cells in a weak magnetic field. And since cells naturally live in a 3-D space, not a 2-D culture, the brain cancer cells actually behaved more normally while suspended in the magnetic field then they did when in a cell culture.
The obvious next step involved programming detailed magnetic fields that float stem cells in the exact spots needed for them to grow into a full organ. To that end, the researchers have sold the technology to the company n3D Bioscences. Whether or not this process leaves your replacement organ magnetic, and how that will affect getting through airports, remains to be seen.

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Source: PopSci - http://www.popsci.com/science/article/2010-03/metal-nano-particles-suspend-human-cells-magnetic-scaffolding-organ-manufactoring

(NanoRealm) - For the first time, scientists have succeeded in growing empty particles derived from a plant virus and have made them carry useful chemicals.

The external surface of these nano containers could be decorated with molecules that guide them to where they are needed in the body, before the chemical load is discharged to exert its effect on diseased cells. The containers are particles of the Cowpea mosaic virus, which is ideally suited for designing biomaterial at the nanoscale.

"This is a shot in the arm for all Cowpea mosaic virus technology," says Professor George Lomonossoff of the John Innes Centre, one of the authors on a paper to be published in the specialised nanotechnology scientific journal, Small.
Scientists have previously tried to empty virus particles of their genetic material using irradiation or chemical treatment. Though successful in rendering the particles non-infectious, these methods have not fully emptied the particles.

Scientists at the John Innes Centre, funded by the BBSRC and the John Innes Foundation, discovered they could assemble empty particles from precursors in plants and then extract them to insert chemicals of interest. Scientists at JIC and elsewhere had also previously managed to decorate the surface of virus particles with useful molecules.

"But now we can load them too, creating fancy chemical containers," says lead author Dr Dave Evans.

"This brings a huge change to the whole technology and opens up new areas of research," says Prof Lomonossoff. "We don't really know all the potential applications yet because such particles have not been available before. There is no history of them."
One application could be in cancer treatment. Integrins are molecules that appear on cancer cells. The virus particles could be coated externally with peptides that bind to integrins. This would mean the particles seek out cancer cells to the exclusion of healthy cells. Once bound to the cancer cell, the virus particle would release an anti-cancer agent that has been carried as an internal cargo.

Some current drugs damage healthy cells as well as the cancer, leading to hair loss and other side effects. This technology could deliver the drug in a more targeted way.
"The potential for developing Cowpea mosaic virus as a targeted delivery agent of therapeutics is now a reality," says Dr Evans.

The empty viral particles, their use, and the processes by which they are made, are the subject of a new patent filing. Management of the patent and commercialisation of the technology is being handled by PBL.

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More information: "Cowpea Mosaic Virus Unmodified Empty Virus-Like Particles Can Be Loaded with Metal and Metal Oxide." DOI:10.1002/smll.200902135

Provided by Norwich BioScience Institutes

Nanotechnology Shows Promise for Use in Treatments for Melanoma, other Skin Conditions

(NanoRealm) - Recent research suggests how the popular skin filler hyaluronic acid works to rejuvenate photoaged skin, and nanotechnology may have potential for use in cosmetic products and topical medical treatments, according to two presentations this week at the annual meeting of the American Academy of Dermatology, held from March 5 to 9 in Miami Beach, Fla.
In one presentation, Dana L. Sachs, M.D., of the University of Michigan in Ann Arbor, presented results of an initial study of six patients showing that hyaluronic acid injections stimulate production of type I collagen, and a subsequent study of 11 patients showing that the mechanism behind this process is increased activity of fibroblasts, which were observed at four and 13 weeks following injection to be in a 'stretched' configuration that correlates with increased collagen production.

In a second presentation, Adnan Nasir, M.D., of the University of North Carolina in Chapel Hill, discussed the pros and cons of nanotechnology and how nanoparticles may someday be used to enhance the effectiveness of cosmetic products such as sunscreens, shampoos and conditioners; anti-aging products such as retinoids, antioxidants, botulinum toxin, and growth factors; and treatments for conditions such as melanoma, atopic dermatitis, and ichthyosis. However, he cautioned that the future of nanotechnology in dermatology depends on the results of an ongoing safety review by the U.S. Food and Drug Administration.

"Research in the area of nanotechnology has increased significantly over the years, and I think there will be considerable growth in this area in the near future," Nasir said in a statement. "The challenge is that a standard has not been set yet to evaluate the safety and efficacy of topical products that contain nanosized particles."

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Source: Modern Medicine (web)
Press Release for:
1) "Research Reveals How Popular Skin Filler Works at the Molecular Level to Stimulate Collagen Production in Sun-Damaged Skin" - Sachs
2) "Sizing Up Nanotechnology: How Nanosized Particles May Affect Skin Care Products" - Nasir

(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.

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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.

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

(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.

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Source: Montana State University

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

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

(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.

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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.

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Source: PhyOrg.com (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.

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Source-ANI

News from: MedIndia - (web)

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.

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

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/

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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.

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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