Articles from April 2013



Nanotrain For Targeted Cancer Drug Transport

University of Florida researchers have developed a “DNA nanotrain” that fast-tracks its payload of cancer-fighting drugs and bioimaging agents to tumor cells deep within the body. The nanotrain’s ability to cost-effectively deliver high doses of drugs to precisely targeted cancers and other medical maladies without leaving behind toxic nano-clutter has been the elusive Holy Grail for scientists studying the teeny-tiny world of DNA nanotechnology.
nano_train-nanochain

Most nanotechnology relies on a nanoparticle approach, and the particles are made of inorganic materials; after they’ve been used as a carrier for the drug, they’ll be left inside the body,” said the study’s lead investigator, Weihong Tan, a UF distinguished professor of chemistry, professor of physiology and functional genomics, and a member of the UF Shands Cancer Center and the UF Genetics Institute. “Compared to existing nanostructures, our nanotrain is easier and cheaper to make, is highly specific to cancer cells, has a lot of drug-loading power and is very much biocompatible.

DNA nanotechnology holds great promise as a new way to deliver chemotherapy directly to cancer cells, but until now, scientists have not been able to direct nanotherapies to consistently differentiate cancer cells from healthy ones. Other limiting factors include high costs, too-small amounts of drugs delivered and potential toxic side effects.
Source: http://news.ufl.edu/

Targeting Parkinson’s Disease At Its Roots

Researchers at Northeastern University in Boston have developed a gene therapy approach that may one day stop Parkinson’s disease (PD) in it tracks, preventing disease progression and reversing its symptoms. Each year, 60,000 adults are newly diag­nosed with Parkinson’s dis­ease, a neu­rode­gen­er­a­tive dis­order that causes a slew of symp­toms, including tremors, slowed move­ments, and changes in speech. The drugs cur­rently avail­able to treat PD patients help them regain some of the motor con­trol lost through the dis­ease, but don’t treat the under­lying cause, said Bar­bara Waszczak, a pro­fessor of phar­ma­ceu­tical sci­ences in the Bouvé Col­lege of Health Sci­ences.

parkinson's
Parkinson’s is caused by the death of dopamine neu­rons in a key motor area of the brain called the sub­stantia nigra,” said Waszczak. If you want to treat PD at its roots, she added, then you have to stop the death of these neural cells. In research reported ear­lier this week at the Exper­i­mental Biology 2013 con­fer­ence in Boston, Waszczak and grad­uate stu­dent Brendan Harmon pro­posed a treat­ment approach that does exactly that. What’s more, the method is simple and easy to use.“If we can get at it in the early stages of the dis­ease, when patients are just starting to develop symp­toms, then we might be able to stop the dis­ease from get­ting worse or at least delay the onset of severe symp­toms,” Waszczak explained.

Source: http://www.northeastern.edu/
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http://www.eurekalert.org/

Renewable Energy Fueled By Nature

Researchers at the U.S. Department of Energy’s Brookhaven National Laboratory describe details of a low-cost, stable, effective catalyst that could replace costly platinum in the production of hydrogen. The catalyst, made from renewable soybeans and abundant molybdenum metal, produces hydrogen in an environmentally friendly, cost-effective manner, potentially increasing the use of this clean energy source.
Their ultimate goal is to find ways to use solar energy — either directly or via electricity generated by solar cells — to convert the end products of hydrocarbon combustion, water and carbon dioxide, back into a carbon-based fuel. Dubbed “artificial photosynthesis,” this process mimics how plants convert those same ingredients to energy in the form of sugars. One key step is splitting water, or water electrolysis.
soybean-proteins

By splitting liquid water (H2O) into hydrogen and oxygen, the hydrogen can be regenerated as a gas (H2) and used directly as fuel,” explains Etsuko Sasaki, member of the Broohaven team.
“A very promising route to making a carbon-containing fuel is to hydrogenate carbon dioxide (or carbon monoxide) using solar-produced hydrogen,” adds Fujita, who leads the artificial photosynthesis group in the Brookhaven Chemistry Department.

Source: http://www.bnl.gov/

Very Strong Nanofibers for Airplanes And Bridges

University of Nebraska-Lincoln materials engineers have developed a structural nanofiber that is both strong and tough, a discovery that could transform everything from airplanes and bridges to body armor and bicycles. Their findings are featured on the cover of this week’s April issue of the American Chemical Society’s journal, ACS Nano.

very strong nanofibers
Whatever is made of composites can benefit from our nanofibers,” said the team’s leader, Yuris Dzenis, McBroom Professor of Mechanical and Materials Engineering and a member of UNL‘s Nebraska Center for Materials and Nanoscience. “Our discovery adds a new material class to the very select current family of materials with demonstrated simultaneously high strength and toughness.”
Source: http://newsroom.unl.edu/

Greek Mythology Helps Research Against Brain Cancer

An Indiana University School of Medicine breast cancer surgeon is pursuing research that will utilize glass, gold, nanotechnology and Greek mythology hoping to vanquish breast cancer that has metastasized to the brain. Susan E. Clare, M.D., Ph.D., associate professor of surgery at the IU School of Medicine, is the initiating principal investigator for a $573,000 Department of Defense grant that will allow her to explore a new approach to delivering therapy to brain metastases from primary breast cancer. As did the Greeks of old, Dr. Clare hopes to covertly deliver “warriorsto the enemy stronghold, in this case a metastatic brain tumor. Her research will explore using a cell from the body’s immune system to deliver chemotherapy directly to the brain metastases. The drug or other therapeutic is attached to the nanospheres, which are carried within the immune cell, much as soldiers were carried within the Trojan Horse. The immune cells travel in the bloodstream and release the drug when it has reached the tumor site.

brain metastasis
The problem for almost all drugs, and HER2-targeted drugs are no exception, is that the blood-brain barrier is a significant impediment to delivering therapies in concentrations that can be effective,” Dr. Clare said.

That biological issue caused Dr. Clare to explore other methods of delivering drugs to metastatic brain tumors. Using nanoparticles called “nanoshells,” developed by Naomi J. Halas, Ph.D., D.Sc., director of the Laboratory for Nanophotonics at Rice University, Dr. Clare hopes to target the brain tumors with lapatinib at a dose sufficient to shut down the signaling pathway needed for the cancer cells to proliferate.

Source: http://news.medicine.iu.edu

Photovoltaic Textiles

Researchers at the University of Exeter – United Kingdom – have developed a new photoelectric device that is both flexible and transparent. The device, described in a paper in the journal ACS Nano, converts light into electrical signals by exploiting the unique properties of the recently discovered materials graphene and graphExeter. GraphExeter is the best known room temperature transparent conductor and graphene is the thinnest conductive material. At just a few atoms thick, the newly developed photoelectric device is ultra-lightweight. This, along with the flexibility of its constituent graphene materials, makes it perfect for incorporating into clothing. Such devices could be used to develop photovoltaic textiles enabling clothes to act as solar panels and charge mobile phones while they are being worn.

graphene2Saverio Russo, Professor of Physics at the University of Exeter said: “This new flexible and transparent photosensitive device uses graphene and graphExeter to convert light into electrical signals with efficiency comparable to that found in opaque devices based on graphene and metals.
“We are only just starting to explore the interfaces between different materials at very small scales and, as this research shows, we are revealing unique properties that we never knew existed. Who knows what surprises are just around the corner.

Source: http://www.exeter.ac.uk/

The Most Powerful Batteries On The Planet, A Few Millimeters In Size

Though they be but little, they are fierce. The most powerful batteries on the planet are only a few millimeters in size, yet they pack such a punch that a driver could use a cellphone powered by these batteries to jump-start a dead car battery – and then recharge the phone in the blink of an eye.
Mechanical science and engineering professor William P. King led a group that developed the most powerful microbatteries ever documented.
Developed by researchers at the University of Illinois at Urbana-Champaign, the new microbatteries out-power even the best supercapacitors and could drive new applications in radio communications and compact electronics.
High power batteries -IonCrossing
The graphic illustrates a high power battery technology from the University of Illinois. Ions flow between three-dimensional micro-electrodes in a lithium ion battery.

“Any kind of electronic device is limited by the size of the battery – until now,” King said. “Consider personal medical devices and implants, where the battery is an enormous brick, and it’s connected to itty-bitty electronics and tiny wires. Now the battery is also tiny.
Now, the researchers are working on integrating their batteries with other electronics components, as well as manufacturability at low cost.

Now we can think outside of the box,” said James Pikul, a graduate student and first author of the paper. “It’s a new enabling technology. It’s not a progressive improvement over previous technologies; it breaks the normal paradigms of energy sources. It’s allowing us to do different, new things.

Source: http://news.illinois.edu/

Major Boost In Solar-Cell Efficiency

Throughout decades of research on solar cells, one formula has been considered an absolute limit to the efficiency of such devices in converting sunlight into electricity: Called the Shockley-Queisser efficiency limit, it posits that the ultimate conversion efficiency can never exceed 34 percent for a single optimized semiconductor junction. Now, researchers at the Massachusetts Institute of TechnologyMIT – have shown that there is a way to blow past that limit as easily as today’s jet fighters zoom through the sound barrier — which was also once seen as an ultimate limit. Their work appears this week in a report in the journal Science.

exciton fission
singlet exciton fission. (An exciton is the excited state of a molecule after absorbing energy from a photon.)
While today’s commercial solar panels typically have an efficiency of at most 25 percent, a silicon solar cell harnessing singlet fission should make it feasible to achieve efficiency of more than 30 percent, Baldo says — a huge leap in a field typically marked by slow, incremental progress. In solar cell research, he notes, people are striving “for an increase of a tenth of a percent.”

Solar panel efficiencies can also be improved by stacking different solar cells together, but combining solar cells is expensive with conventional solar-cell materials. The new technology instead promises to work as an inexpensive coating on solar cells.

Source: http://web.mit.edu/

Spray-on Coating Combines Carbon Nanotubes with Ceramic

Researchers from the National Institute of Standards and Technology (NIST) and Kansas State University have demonstrated a spray-on mixture of carbon nanotubes and ceramic that has unprecedented ability to resist damage while absorbing laser light.*
Coatings that absorb as much of the energy of high-powered lasers as possible without breaking down are essential for optical power detectors that measure the output of such lasers, which are used, for example, in military equipment for defusing unexploded mines. The new material improves on NIST‘s earlier version of a spray-on nanotube coating for optical power detectors** and has already attracted industry interest.
spray on super-nanotubeMicrograph of one strand of a new spray-on super-nanotube composite developed by the National Institute of Standards and Technology (NIST) and Kansas State University. The multi-wall nanotube core is surrounded by a ceramic shell. The composite is a promising coating for laser power detectors.
It really is remarkable material,NIST co-author John Lehman says. “It’s a way to make super-nanotubes. It has the optical, thermal and electrical properties of nanotubes with the robustness of the high-temperature ceramic.
Source: http://www.nist.gov/

How To Create NanoComputers

Researchers are developing a new type of semiconductor technology for future computers and electronics based on “two-dimensional nanocrystals” layered in sheets less than a nanometer thick that could replace today’s transistors. New technologies will be needed to allow the semiconductor industry to continue advances in computer performance driven by the ability to create ever-smaller transistors.

semiconductor

We are going to reach the fundamental limits of silicon-based CMOS technology very soon, and that means novel materials must be found in order to continue scaling,” said Saptarshi Das, who has completed a doctoral degree, working with Joerg Appenzeller, a professor and scientific director of nanoelectronics at Purdue‘s Birck Nanotechnology Center. “I don’t think silicon can be replaced by a single material, but probably different materials will co-exist in a hybrid technology.

Source: http://www.purdue.edu/

Nanodiamonds For Breast Cancer Treatment

UCLA researchers led by Professor Dean Ho from the Jane and Jerry Weintraub Center for Reconstructive Biotechnology, have developed a potentially more effective treatment for breast cancer. Doctors have begun to categorize breast cancers into four main groups according to the genetic makeup of the cancer cells. Which category a cancer falls into generally determines the best method of treatment. But cancers in one of the four groups — called “basal-like” or “triple-negative” breast cancer (TNBC) — have been particularly tricky to treat because they usually don’t respond to the “receptor-targeted” treatments that are often effective in treating other types of breast cancer. TNBC tends to be more aggressive than the other types and more likely to recur, and can also have a higher mortality rate. Using nanodiamonds between 4 and 6 nanometers in diameter and shaped like tiny soccer balls, the researchers form clusters following drug binding that have the ability to precisely deliver cancer drugs to tumors, significantly improving the drugs’ desired effect. In the UCLA study, the nanodiamond delivery system has been able to home in on tumor masses in mice with triple negative breast cancer.

nanodiamonds
This study demonstrates the versatility of the nanodiamond as a targeted drug-delivery agent to a tumor site,” said Ho, who is also a member of the California NanoSystems Institute at UCLA, UCLA’s Jonsson Comprehensive Cancer Center and the UCLA Department of Bioengineering. “The agent we’ve developed reduces the toxic side effects that are associated with treatment and mediates significant reductions in tumor size.”
Findings from the study are published online April 15 in the peer-reviewed journal Advanced Materials.
Source: http://newsroom.ucla.edu/

Nanosponges Soak Up Toxins Released By Bacterial Infections

Engineers at the University of California, San Diego have invented a “nanosponge” capable of safely removing a broad class of dangerous toxins from the bloodstream – including toxins produced by MRSA, E. coli, poisonous snakes and bees. These nanosponges, which thus far have been studied in mice, can neutralize “pore-forming toxins,” which destroy cells by poking holes in their cell membranes. Unlike other anti-toxin platforms that need to be custom synthesized for individual toxin type, the nanosponges can absorb different pore-forming toxins regardless of their molecular structures. In a study against alpha-haemolysin toxin from MRSA, pre-innoculation with nanosponges enabled 89 percent of mice to survive lethal doses. Administering nanosponges after the lethal dose led to 44 percent survival. Methicillin-resistant Staphylococcus aureus (MRSA) infection is caused by a strain of staph bacteria that’s become resistant to the antibiotics commonly used to treat ordinary staph infections.

nanosponge
“One of the first applications we are aiming for would be an anti-virulence treatment for MRSA. That’s why we studied one of the most virulent toxins from MRSA in our experiments,” said “Jack” Che-Ming Hu, the first author on the paper. The team, led by nanoengineers at the UC San Diego Jacobs School of Engineering, published the findings in Nature Nanotechnology April 14.
Source: http://www.eurekalert.org/