Articles from June 2017

How To Use Potato Virus To Delay Tumor Progression

Researchers from Case Western Reserve University School of Medicine in collaboration with researchers from Dartmouth Geisel School of Medicine and RWTH Aachen University (Germany) have adapted virus particles—that normally infect potatoes—to serve as cancer drug delivery devices for mice. But in a recent article published in Nano Letters, the team showed injecting the virus particles alongside chemotherapy drugs, instead of packing the drugs inside, may provide an even more potent benefit.

The researchers discovered injecting potato virus particles into melanoma tumor sites activates an anti-tumor immune system response. And simultaneously injecting the nanoscale plant virus particles and a chemotherapy drugdoxorubicin—into tumor sites further helps halt tumor progression in mice. But surprisingly, when the researchers created and injected combination nanoparticles, where the chemo drug is physically attached to the virus particles, there was not a significant added benefit.

The results are the first to show “vaccinating” mice with potato virus nanoparticles at a cancer site can generate an anti-tumor response. But the results also suggest more complex nanoparticles may not correspond to added therapeutic benefit.

It’s attractive to want to create multifunctional nanoparticles that can ‘do it all,’” said Nicole F. Steinmetz, PhD, senior author on the study, George J. Picha Professor in Biomaterials, member of the Case Comprehensive Cancer Center, and Director of the Center for Bio-Nanotechnology at Case Western Reserve School of Medicine.But this study shows significant therapeutic efficacy, including prolonging survival, requires a more step-wise approach. When the plant-based virus particles and the drugs were able to work on their own, we saw the greatest benefit.”

Wrote the authors, “While the nanomedicine field strives to design multifunctional nanoparticles that integrate several functions and therapeutic regimens into single nanoparticle – our data suggest a paradigm shift; some therapeutics may need to be administered separately to synergize and achieve most potent therapeutic outcome.”


NanoRobots Trap Bacteria And Clean Water

The lack of clean water in many areas around the world is a persistent, major public health problem. One day, tiny robots could help address this issue by zooming around contaminated water and cleaning up disease-causing bacteria. Scientists from the Max-Planck Institute for Intelligent Systems (Germany) and  the Institute for Bioengineering of Catalonia (IBEC) report a new development toward this goal in the journal ACS Applied Materials & Interfaces.

Drinking water contaminated with pathogenic bacteria can cause serious illnesses that, in areas with spotty medical services, are potentially life-threatening without proper treatment. Water can be disinfected with chlorine or other disinfectants, but there are some hardy bacteria and other microorganisms that are hard to remove. Treating water with a combination of disinfectants or increasing their concentrations can help. But they remain in the water, and their byproducts can be harmful to human health. In recent years, researchers have been exploring the use of self-propelled micromotors to degrade and capture pollutants in water. Building on this work, Diana Vilela, Samuel Sánchez Ordóñez (IBEC) and colleagues wanted to see if they could engineer tiny robots to remove waterborne bacteria.

The team designed “two-facedspherical particles to perform the task. One face is made with magnesium, which reacts with water to produce hydrogen bubbles to propel the microbots. The other face is made out of alternating iron and gold layers topped by silver nanoparticles. Bacteria stick to the gold and are killed by the silver nanoparticles. Lab testing showed that the particles can motor around in water for 15 to 20 minutes before the magnesium is spent. And they trapped more than 80 percent of E. coli in water spiked with a high concentration of the bacteria. Then, because of the iron’s magnetic properties, the microbots are removed easily with a magnet, without leaving behind any harmful waste in the water.


How To Boost Body’s Cancer Defenses

After radiation treatment, dying cancer cells spit out mutated proteins into the body. Scientists now know that immune system can detect these proteins and kill cancer in other parts of the body using these protein markers as a guide – a phenomenon that University of North Carolina Lineberger Comprehensive Cancer Center (UNC Lineberg) scientists are looking to harness to improve cancer treatment.

In the journal Nature Nanotechnology, the researchers report on strides made in the development of a strategy to improve the immune system’s detection of cancer proteins by using “stickynanoparticles called “antigen-capturing nanoparticles.” They believe these particles could work synergistically with immunotherapy drugs designed to boost the immune system’s response to cancer.

Our hypothesis was that if we use a nanoparticle to grab onto these cancer proteins, we’d probably get a more robust immune response to the cancer,” said the study’s senior author Andrew Z. Wang, MD, a UNC Lineberger member and associate professor in the UNC School of Medicine Department of Radiation Oncology. “We think it works because nanoparticles are attractive to the immune system. Immune cells don’t like anything that’s nano-sized; they think they are viruses, and will respond to them.”

Radiation therapy is commonly used to treat a wide array of cancers. Previously, doctors have observed a phenomenon they call the “abscopal effect,” in which a patient experiences tumor shrinkage outside of the primary site that was treated with radiation. This observation in a single patient with melanoma was reported in the New England Journal of Medicine in 2012.

Scientists believe this occurs because, after radiation, immune cells are recruited to the tumor site. Once they’ve arrived, these immune cells use mutated proteins released by dying cancer cells to train other immune cells to recognize and fight cancer elsewhere. This effect works synergistically with immunotherapy drugs called “checkpoint inhibitors,” which release the immune system’s brakes, thereby helping the body’s own defense system to attack the cancer.

Cancer cells discharge these mutated proteins – which become markers for the immune system — as a result of genetic mutations, said study co-author Jonathan Serody, MD, UNC Lineberger’s associate director for translational research.

The theory is that in cancer, tumors accumulate large numbers of mutations across their genomes, and those mutated genes can make mutant proteins, and any of those mutant proteins can be chopped up and presented to the immune system as a foreign,” said Serody, who is also the Elizabeth Thomas Professor in the UNC School of Medicine. “Your body is designed not to respond to its own proteins, but there’s no system that controls its response to new proteins, and you have a broad array of immune cells that could launch a response to them.

The UNC Lineberger researchers demonstrated in preclinical studies they could successfully design nanoparticles to capture mutated proteins released by tumors. Once these nanoparticles are taken up by immune cells, the tumor proteins attached to their surface can help immune cells recognize identify cancer cells across body.


How To Repair Connections Between Nerve Cells

Carbon nanotubes exhibit interesting characteristics rendering them particularly suited to the construction of special hybrid devices – consisting of biological tissue and synthetic material – planned to re-establish connections between nerve cells, for instance at spinal level, lost on account of lesions or trauma. This is the result of a piece of research published on the scientific journal Nanomedicine: Nanotechnology, Biology, and Medicine conducted by a multi-disciplinary team comprising SISSA (International School for Advanced Studies), the University of Trieste, ELETTRA Sincrotrone and two Spanish institutions, Basque Foundation for Science and CIC BiomaGUNE. More specifically, researchers have investigated the possible effects on neurons of the interaction with carbon nanotubes. Scientists have proven that these nanomaterials may regulate the formation of synapses, specialized structures through which the nerve cells communicate, and modulate biological mechanisms, such as the growth of neurons, as part of a self-regulating process. This result, which shows the extent to which the integration between nerve cells and these synthetic structures is stable and efficient, highlights the great potentialities of carbon nanotubes as innovative materials capable of facilitating neuronal regeneration or in order to create a kind of artificial bridge between groups of neurons whose connection has been interrupted. In vivo testing has actually already begun.

Scientists have proven that these nanomaterials may regulate the formation of synapses, specialized structures through which the nerve cells communicate, and modulate biological mechanisms, such as the growth of neurons, as part of a self-regulating process

Interface systems, or, more in general, neuronal prostheses, that enable an effective re-establishment of these connections are under active investigation” explain Laura Ballerini (SISSA) and Maurizio Prato (UniTSCIC BiomaGUNE), coordinating the research project. “The perfect material to build these neural interfaces does not exist, yet the carbon nanotubes we are working on have already proved to have great potentialities. After all, nanomaterials currently represent our best hope for developing innovative strategies in the treatment of spinal cord injuries“. These nanomaterials are used both as scaffolds, a supportive framework for nerve cells, and as means of interfaces releasing those signals that empower nerve cells to communicate with each other.


Building Brain-Inspired AI Supercomputing System

IBM (NYSE: IBM) and the U.S. Air Force Research Laboratory (AFRL) today announced they are collaborating on a first-of-a-kind brain-inspired supercomputing system powered by a 64-chip array of the IBM TrueNorth Neurosynaptic System. The scalable platform IBM is building for AFRL will feature an end-to-end software ecosystem designed to enable deep neural-network learning and information discovery. The system’s advanced pattern recognition and sensory processing power will be the equivalent of 64 million neurons and 16 billion synapses, while the processor component will consume the energy equivalent of a dim light bulb – a mere 10 watts to power.
IBM researchers believe the brain-inspired, neural network design of TrueNorth will be far more efficient for pattern recognition and integrated sensory processing than systems powered by conventional chips. AFRL is investigating applications of the system in embedded, mobile, autonomous settings where, today, size, weight and power (SWaP) are key limiting factors. The IBM TrueNorth Neurosynaptic System can efficiently convert data (such as images, video, audio and text) from multiple, distributed sensors into symbols in real time. AFRL will combine this “right-brain perception capability of the system with the “left-brain” symbol processing capabilities of conventional computer systems. The large scale of the system will enable both “data parallelism” where multiple data sources can be run in parallel against the same neural network and “model parallelism” where independent neural networks form an ensemble that can be run in parallel on the same data.


AFRL was the earliest adopter of TrueNorth for converting data into decisions,” said Daniel S. Goddard, director, information directorate, U.S. Air Force Research Lab. “The new neurosynaptic system will be used to enable new computing capabilities important to AFRL’s mission to explore, prototype and demonstrate high-impact, game-changing technologies that enable the Air Force and the nation to maintain its superior technical advantage.”

“The evolution of the IBM TrueNorth Neurosynaptic System is a solid proof point in our quest to lead the industry in AI hardware innovation,” said Dharmendra S. Modha, IBM Fellow, chief scientist, brain-inspired computing, IBM Research – Almaden. “Over the last six years, IBM has expanded the number of neurons per system from 256 to more than 64 million – an 800 percent annual increase over six years.’’


Nanotechnology Spacecraft

Renowned physicist Stephen Hawking is proposing a nanotechnology spacecraft that can travel at a fifth of the speed of light. At that speed, it could reach the nearest star in 20 years and send back images of a suspected “Second Earth” within 5 years. That means if we launched it today, we would have our first look at an Earth-like planet within 25 years.

Hawking proposed a nano-spacecraft, termed “Star Chip,” at the Starmus Festival IV: Life And The Universe, Trondheim, Norway, June 18 – 23, 2017. Hawking told attendees that every time intelligent life evolves it annihilates itself with “war, disease and weapons of mass destruction.” He asserted this as the primary reason why advanced civilizations from another part of the Universe are not contacting Earth and the primary reason we need to leave the Earth. His advocates we colonize a “Second Earth.”

Scientific evidence appears to support Hawking’s claim. The SETI Institute has been listening for evidence of extraterrestrial radio signals, a sign of advanced extraterrestrial life, since 1984. To date, their efforts have been futile. SETI claims, rightly, that the universe is vast, and they are listening to only small sectors, which is much like finding a needle in a haystack.


3-D Printed Graphene Foam

Nanotechnologists from Rice University and China’s Tianjin University have used 3-D laser printing to fabricate centimeter-sized objects of atomically thin graphene. The research could yield industrially useful quantities of bulk graphene and is described online in a new study in the American Chemical Society journal ACS Nano.

Laser sintering was used to 3-D print objects made of graphene foam, a 3-D version of atomically thin graphene. At left is a photo of a fingertip-sized cube of graphene foam; at right is a close-up of the material as seen with a scanning electron microscope

This study is a first of its kind,” said Rice chemist James Tour, co-corresponding author of the paper. “We have shown how to make 3-D graphene foams from nongraphene starting materials, and the method lends itself to being scaled to graphene foams for additive manufacturing applications with pore-size control.”

Graphene, one of the most intensely studied nanomaterials of the decade, is a two-dimensional sheet of pure carbon that is both ultrastrong and conductive. Scientists hope to use graphene for everything from nanoelectronics and aircraft de-icers to batteries and bone implants. But most industrial applications would require bulk quantities of graphene in a three-dimensional form, and scientists have struggled to find simple ways of creating bulk 3-D graphene.

For example, researchers in Tour’s lab began using lasers, powdered sugar and nickel to make 3-D graphene foam in late 2016. Earlier this year they showed that they could reinforce the foam with carbon nanotubes, which produced a material they dubbed “rebar graphene” that could retain its shape while supporting 3,000 times its own weight. But making rebar graphene was no simple task. It required a pre-fabricated 3-D mold, a 1,000-degree Celsius chemical vapor deposition (CVD) process and nearly three hours of heating and cooling.  “This simple and efficient method does away with the need for both cold-press molds and high-temperature CVD treatment,” said co-lead author Junwei Sha, a former student in Tour’s lab who is now a postdoctoral researcher at Tianjin. “We should also be able to use this process to produce specific types of graphene foam like 3-D printed rebar graphene as well as both nitrogen- and sulfur-doped graphene foam by changing the precursor powders.” Sha and colleagues conducted an exhaustive study to find the optimal amount of time and laser power to maximize graphene production. The foam created by the process is a low-density, 3-D form of graphene with large pores that account for more than 99 percent of its volume.

The 3-D graphene foams prepared by our method show promise for applications that require rapid prototyping and manufacturing of 3-D carbon materials, including energy storage, damping and sound absorption,” said co-lead author Yilun Li, a graduate student at Rice.


Solar Energy Transforms Salt Water Into Fresh Drinking Water

A federally funded research effort to revolutionize water treatment has yielded an off-grid technology that uses energy from sunlight alone to turn salt water into fresh drinking water. The desalination system, which uses a combination of membrane distillation technology and light-harvesting nanophotonics, is the first major innovation from the Center for Nanotechnology Enabled Water Treatment (NEWT), a multi-institutional engineering research center based at Rice University.

NEWT’s “nanophotonics-enabled solar membrane distillation” technology, or NESMD, combines tried-and-true water treatment methods with cutting-edge nanotechnology that converts sunlight to heat. More than 18,000 desalination plants operate in 150 countries, but NEWT’s desalination technology is unlike any other used today.

Direct solar desalination could be a game changer for some of the estimated 1 billion people who lack access to clean drinking water,” said Rice scientist and water treatment expert Qilin Li, a corresponding author on the study. “This off-grid technology is capable of providing sufficient clean water for family use in a compact footprint, and it can be scaled up to provide water for larger communities.”

The technology is described online in the Proceedings of the National Academy of Sciences.


Quantum Satellite Secures Communications

A Chinese quantum satellite has dispatched transmissions over a distance of 1,200 km (746 miles), a dozen times further than the previous record, a breakthrough in a technology that could be used to deliver secure messages, state media said on Friday.

China launched the world’s first quantum satellite last August, to help establish “hack proof” communications between space and the ground, state media said at the time.

The feat opens up “bright prospects” for quantum communications, said Pan Jianwei, the lead scientist of the Chinese team, Quantum Experiments at Space Scale (QUESS), according to the official Xinhua news agency.

The scientists exploited the phenomenon of quantum entanglement, in which a particle can affect a far-off twin instantly, somehow overcoming the long distance separating them, a situation termed “spooky action at a distance” by the Nobel-prize winning physicist Albert Einstein, Xinhua added.

The team had successfully distributed entangled photon pairs over 1,200 km, it said, outstripping the distance of up to 100 km (62 miles) at which entanglement had previously been achieved.

The technology so far is “the only way to establish secure keys between two distant locations on earth without relying on trustful relay,” Pan told Xinhua, referring to encrypted messages.

The new development “illustrates the possibility of a future global quantum communication network” the journal Science, which published the results of the Chinese team, said on its website.


Artificial Intelligence At The Hospital

Diagnosing cancer is a slow and laborious process. Here researchers at University Hospital Zurich painstakingly make up biopsy slides – up to 50 for each patient – for the pathologist to examine for signs of prostate cancer. A pathologist takes around an hour and a half per patient – a task IBMs Watson supercomputer is now doing in fractions of a second.

“If the pathologist becomes faster by using such a system I think it will pay off. Because my time is also worth something. If I sit here one and a half hours looking at slides, screening all these slides, instead of just signing out the two or three positive ones, and taking into account that there may be a .1 error rate, percent error rate. this will pay off, because I can do in one and a half hours at the end five patients,” says Dr. Peter Wild, University Hospital Zürich.

The hospital’s archive of biopsy images is being slowly fed into Watson – a process that will take years. But maybe one day pathologists won’t have to view slides through a microscope at all. Diagnosis is not the only area benefiting from AI. The technology is helping this University of Sheffield team design a new drug that could slow down the progress of motor neurone disease. A system built by British start-up BenevolentAI is identifying new areas for further exploration far faster than a person could ever hope to.

Benevolent basically uses their artificial intelligence system to scan the whole medical and biomedical literature. It’s not really easy for us to stay on top of millions of publications that come out every year. So they can interrogate that information, using artificial intelligence and come up with ideas for new drugs that might be used in a completely different disease, but may be applicable on motor neurone disease. So that’s the real benefit in their system, the kind of novel ideas that they come up with,” explains Dr. Richard Mead, Sitran, University of Sheffield. BenevolentAI has raised one hundred million dollars in investment to develop its AI system, and help revolutionise the pharmaceutical industry.


Nanoscale Memory Cell

Developing a superconducting computer that would perform computations at high speed without heat dissipation has been the goal of several research and development initiatives since the 1950s. Such a computer would require a fraction of the energy current supercomputers consume, and would be many times faster and more powerful. Despite promising advances in this direction over the last 65 years, substantial obstacles remain, including in developing miniaturized low-dissipation memory.

Researchers at the University of Illinois at Urbana-Champaign have developed a new nanoscale memory cell that holds tremendous promise for successful integration with superconducting processors. The new technology, created by Professor of Physics Alexey Bezryadin and graduate student Andrew Murphy, in collaboration with Dmitri Averin, a professor of theoretical physics at State University of New York at Stony Brook, provides stable memory at a smaller size than other proposed memory devices.

The device comprises two superconducting nanowires, attached to two unevenly spaced electrodes that were “written” using electron-beam lithography. The nanowires and electrodes form an asymmetric, closed superconducting loop, called a nanowire ‘SQUID’ (superconducting quantum interference device). The direction of current flowing through the loop, either clockwise or counterclockwise, equates to the “0” or “1” of binary code.

This is very exciting. Such superconducting memory cells can be scaled down in size to the range of few tens of nanometers, and are not subject to the same performance issues as other proposed solutions,” comments Bezryadin.

Murphy adds, “Other efforts to create a scaled-down superconducting memory cell weren’t able to reach the scale we have. A superconducting memory device needs to be cheaper to manufacture than standard memory now, and it needs to be dense, small, and fast.”


Nano-based Material Is 60 Times More Efficient To Produce Hydrogen

Global climate change and the energy crisis mean that alternatives to fossil fuels are urgently needed. Among the cleanest low-carbon fuels is hydrogen, which can react with oxygen to release energy, emitting nothing more harmful than water (H2O) as the product. However, most hydrogen on earth is already locked into H2O (or other molecules), and cannot be used for power.

Hydrogen can be generated by splitting H2O, but this uses more energy than the produced hydrogen can give back. Water splitting is often driven by solar power, so-called “solar-to-hydrogenconversion. Materials like titanium oxide, known as semiconductors with the wide band-gap, are traditionally used to convert sunlight to chemical energy for the photocatalytic reaction. However, these materials are inefficient because only the ultraviolet (UV) part of light is absorbed—the rest spectrum of sunlight is wasted.

Now, a team in Osaka University has developed a material to harvest a broader spectrum of sunlight. The three-part composites of this material maximize both absorbing light and its efficiency for water splitting. The core is a traditional semiconductor, lanthanum titanium oxide (LTO). The LTO surface is partly coated with tiny specks of gold, known as nanoparticles. Finally, the gold-covered LTO is mixed with ultrathin sheets of the element black phosphorus (BP), which acts as a light absorber.

BP is a wonderful material for solar applications, because we can tune the frequency of light just by varying its thickness, from ultrathin to bulk,” the team leader Tetsuro Majima says. “This allows our new material to absorb visible and even near infrared light, which we could never achieve with LTO alone.”

By absorbing this broad sweep of energy, BP is stimulated to release electrons, which are then conducted to the gold nanoparticles coating the LTO. Gold nanoparticles also absorb visible light, causing some of its own electrons to be jolted out. The free electrons in both BP and gold nanoparticles are then transferred into the LTO semiconductor, where they act as an electric current for water splitting.

Hydrogen production using this material is enhanced not only by the broader spectrum of light absorption, but by the more efficient electron conduction, caused by the unique interface between two dimensional materials of BP and LTO. As a result, the material is 60 times more active than pure LTO.