Green Solar Panels And Other Colors

Researchers from AMOLF, the University of Amsterdam (UvA) and the Energy Research Centre of the Netherlands (ECN) have developed a technology to create efficient bright green colored solar panels. Arrays of silicon nanoparticles integrated in the front module glass of a silicon heterojunction solar cell scatter a narrow band of the solar spectrum and create a green appearance for a wide range of angles. The remainder of the solar spectrum is efficiently coupled into the solar cell. The current generated by the solar panel is only  reduced by 10%. The realization of efficient colorful solar panels is an important step for the integration of solar panels into the built environment and landscape.
research has much focused on maximizing the electricity yield obtained from solar panels: nowadays, commercial panels have a maximum conversion efficiency from sunlight into electricity of around 22%. To reach such high efficiency, silicon solar cells have been equipped with a textured surface with an antireflection layer to absorb as much light as possible. This creates a dark blue or black appearance of the solar panels.

To create the colored solar panels the researchers have used the effect of Mie scattering, the resonant backscattering of light with a particular color by nanoparticles. They integrated dense arrays of silicon nanocylinders with a diameter of 100 nm in the top module cover slide of a high-efficiency silicon heterojunction solar cell. Due to the resonant nature of the light scattering effect, only the green part of the spectrum is reflected; the other colors are fully coupled into the solar cell. The current generated by the mini solar panel (0,7 x 0,7 cm2)  is only reduced by 10%. The solar panel appears green over a broad range of angles up to 75 degrees. The nanoparticles are fabricated using soft-imprint lithography, a technique that can readily be scaled up to large-area fabrication.
The light scattering effect due to Mie resonances is easily controllable: by changing the size of the nanoparticles the wavelength of the resonant light scattering can be tuned. Following this principle the researchers are now working to realize solar cells in other colors, and on a combination of different colors to create solar panels with a white appearance. For the large-scale application of solar panels, it is essential that their color can be tailored.

The new design was published online in the journal Applied Physics Letters.


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.


A Single Drop Of Blood To Test Agressive Prostate Cancer

A new diagnostic developed by Alberta scientists will allow men to bypass painful biopsies to test for aggressive prostate cancer. The test incorporates a unique nanotechnology platform to make the diagnostic using only a single drop of blood, and is significantly more accurate than current screening methods.

The Extracellular Vesicle Fingerprint Predictive Score (EV-FPS) test uses machine learning to combine information from millions of cancer cell nanoparticles in the blood to recognize the unique fingerprint of aggressive cancer. The diagnostic, developed by members of the Alberta Prostate Cancer Research Initiative (APCaRI), was evaluated in a group of 377 Albertan men who were referred to their urologist with suspected prostate cancer. It was found that EV-FPS correctly identified men with aggressive prostate cancer 40 percent more accurately than the most common test—Prostate-Specific Antigen (PSA) blood test—in wide use today.

Higher sensitivity means that our test will miss fewer aggressive cancers,” said John Lewis, the Alberta Cancer Foundation‘s Frank and Carla Sojonky Chair of Prostate Cancer Research at the University of Alberta. “For this kind of test you want the sensitivity to be as high as possible because you don’t want to miss a single cancer that should be treated.”

According to the team, current tests such as the PSA and digital rectal exam (DRE) often lead to unneeded biopsies. Lewis says more than 50 per cent of men who undergo biopsy do not have prostate cancer, yet suffer the pain and side effects of the procedure such as infection or sepsis. Less than 20 per cent of men who receive a are diagnosed with the aggressive form of prostate cancer that could most benefit from treatment.

It’s estimated that successful implementation of the EV-FPS test could eventually eliminate up to 600-thousand unnecessary biopsies, 24-thousand hospitalizations and up to 50 per cent of unnecessary treatments for prostate each year in North America alone. Beyond cost savings to the health care system, the researchers say the diagnostic test will have a dramatic impact on the health care experience and quality of life for men and their families.

Compared to elevated total PSA alone, the EV-FPS test can more accurately predict the result of prostate biopsy in previously unscreened men,” said Adrian Fairey, urologist at the Northern Alberta Urology Centre and member of APCaRI. “This information can be used by clinicians to determine which men should be advised to undergo immediate prostate biopsy and which men should be advised to defer and continue screening.”


How Yo Make Sea Water Drinkable

Graphene-oxide membranes have attracted considerable attention as promising candidates for new filtration technologies. Now the much sought-after development of making membranes capable of sieving common salts has been achieved. New research demonstrates the real-world potential of providing clean drinking water for millions of people who struggle to access adequate clean water sources. Graphene-oxide membranes developed at the National Graphene Institute have already demonstrated the potential of filtering out small nanoparticles, organic molecules, and even large salts. Until now, however, they couldn’t be used for sieving common salts used in desalination technologies, which require even smaller sieves. Previous research at The University of Manchester found that if immersed in water, graphene-oxide membranes become slightly swollen and smaller salts flow through the membrane along with water, but larger ions or molecules are blocked.

The Manchester-based group have now further developed these graphene membranes and found a strategy to avoid the swelling of the membrane when exposed to water. The pore size in the membrane can be precisely controlled which can sieve common salts out of salty water and make it safe to drink.


Realisation of scalable membranes with uniform pore size down to atomic scale is a significant step forward and will open new possibilities for improving the efficiency of desalination technology,” says Professor Rahul Raveendran Nair.

The new findings from a group of scientists at The University of Manchester have been published in the journal Nature Nanotechnology.


Wood Mixed With Nanoparticles Filters Toxic Water

Engineers at the University of Maryland have developed a new use for wood: to filter water. Liangbing Hu of the Energy Research Center and his colleagues added nanoparticles to wood, then used it to filter toxic dyes from water.

The team started with a block of linden wood, which they then soaked in palladium – a metal used in cars’ catalytic converters to remove pollutants from the exhaust. In this new filter, the palladium bonds to particles of dye. The wood’s natural channels, that once moved water and nutrients between the leaves and roots, now allow the water to flow past the nanoparticles for efficient removal of the toxic dye particles. The water, tinted with methylene blue, slowly drips through the wood and comes out clear.

VIDEO: Wood filter removes toxic dye from water

This could be used in areas where wastewater contains toxic dye particles,” said Amy Gong, a materials science graduate student, and co-first author of the research paper.

The purpose of the study was to analyze wood via an engineering lens. The researchers did not compare the filter to other types of filters; rather, they wanted to prove that wood can be used to remove impurities.

We are currently working on using a wood filter to remove heavy metals, such as lead and copper, from water,’ said Liangbing Hu, the lead researcher on the project. “We are also interested in scaling up the technology for real industry applications.” Hu is a professor of materials science and a member of the University of Maryland’s Energy Research Center.


Nanoparticles From Air Pollution Travel Into Blood To Cause Heart Disease

Inhaled nanoparticles – like those released from vehicle exhausts – can work their way through the lungs and into the bloodstream, potentially raising the risk of heart attack and stroke, according to new research part-funded by the British Heart Foundation. The findings, published today in the journal ACS Nano, build on previous studies that have found tiny particles in air pollution are associated with an increased risk of cardiovascular disease, although the cause remains unproven. However, this research shows for the first time that inhaled nanoparticles can gain access to the blood in healthy individuals and people at risk of stroke. Most worryingly, these nanoparticles tend to build-up in diseased blood vessels where they could worsen coronary heart disease – the cause of a heart attack.

It is not currently possible to measure environmental nanoparticles in the blood. So, researchers from the University of Edinburgh, and the National Institute for Public Health and the Environment in the Netherlands, used a variety of specialist techniques to track the fate of harmless gold nanoparticles breathed in by volunteers. They were able to show that these nanoparticles can migrate from the lungs and into the bloodstream within 24 hours after exposure and were still detectable in the blood three months later. By looking at surgically removed plaques from people at high risk of stroke they were also able to find that the nanoparticles accumulated in the fatty plaques that grow inside blood vessels and cause heart attacks and strokesCardiovascular disease (CVD) – the main forms of which are coronary heart disease and stroke – accounts for 80% of all premature deaths from air pollution.


It is striking that particles in the air we breathe can get into our blood where they can be carried to different organs of the body. Only a very small proportion of inhaled particles will do this, however, if reactive particles like those in air pollution then reach susceptible areas of the body then even this small number of particles might have serious consequences,”  said Dr Mark Miller, Senior Research Fellow at the University of Edinburgh who led the study.


Frozen Organs Get Life Via Nanotechnology

Scientists are developing a new method to safely bring frozen organs back to life using nanotechnology, an advance that may make donated organs for transplants available to virtually everyone who needs them.

A research team, led by the University of Minnesota, has discovered a groundbreaking process to successfully rewarm large-scale animal heart valves and blood vessels preserved at very low temperatures. The discovery is a major step forward in saving millions of human lives by increasing the availability of organs and tissues for transplantation through the establishment of tissue and organ banks.


This is the first time that anyone has been able to scale up to a larger biological system and demonstrate successful, fast, and uniform warming hundreds of degrees Celsius per minute of preserved tissue without damaging the tissue,” said University of Minnesota mechanical engineering and biomedical engineering professor John Bischof, the senior author of the study.

The researchers manufactured silica-coated nanoparticles that contained iron oxide. When they applied a magnetic field to frozen tissues suffused with the nanoparticles, the nanoparticles generated heat rapidly and uniformly.

Currently, more than 60 percent of the hearts and lungs donated for transplantation must be discarded each year because these tissues cannot be kept on ice for longer than four hours. According to recent estimates, if only half of unused organs were successfully transplanted, transplant waiting lists could be eliminated within two years.

The research was published  in Science Translational Medicine, a peer-reviewed research journal published by the American Association for the Advancement of Sciences (AAAS). The University of Minnesota holds two patents related to this discovery.


How To Improve Hair Treatment

In shampoo ads, hair always looks like a shiny, smooth surface. But for physicists peering into microscopes, the hair surface looks much more rugged, as it is made of saw-tooth, ratchet-like scales. In a new theoretical study published in EPJ E, Matthias Radtke and Roland Netz have demonstrated that massaging hair can help to apply drug treatmentencapsulated in nanoparticles trapped in the channels formed around individual hairs – to the hair roots. This is because the oscillatory movement of the massaging directs the way these particles are transported.


This phenomenon was previously discovered in experiments on pork skin samples, which were conducted by Jürgen Lademann, dermatologist at the Charité clinic in Berlin, Germany, and his team. It is also relevant at the microscopic scale, in the transport on microtubules taking place in two directions between the cells within our bodies. By constrast, these findings could also help find ways of preventing harmful nanoparticles from being transported along hairs into the wrong places.

In their work, the authors created a model in which a nanoparticle moves between two asymmetric surfaces. Using standard models of random motion, they moved one surface in an oscillatory fashion relative to the other. They demonstrated by virtue of their corrugated surfaces that channels created between individual hairs and the surrounding skin lead to nanoparticles being sucked into hair follicles if the hair is massaged, thanks to a “ratchetmechanism.

Further, the authors determined optimal transport conditions for different surface structures by varying the driving frequency, particle size, and the amplitude of the corrugated surface. They found that the ratchet effect switches from a flashing to a pushing effect, when the oscillation switches from perpendicular to parallel to the resting surface, respectively. Radtke and Netz also found that nanoparticles’ speed and ability to diffuse are greatly enhanced by the parallel oscillatory motion.


Understanding The Risks Of Nanotechnology

When radioactive materials were first introduced into society, it took a while before scientists understood the risks. The same is true of nanotechnology today, according to Dr Vladimir Baulin, from University Rovira i Virgili, in Tarragona, Spain, who together with colleagues has shown for the first time how nanoparticles can cross biological – or lipidmembranes in a paper published in the journal Science Advances
Nanotechnology is all around us, in building materials, in toothpaste and in cleaning products. Across Europe, hundreds of institutions are working together to look at how to monitor exposure, manage the risks and advise on what regulations may be needed under the EU’s NanoSafety Cluster.

nanoparticles effects on lipids

This is the first observation to show directly how tiny gold nanoparticles can cross a lipid bilayer (main part of a biological membrane). This process was quantified and the time of each step was estimated. The lipid membrane is the ultimate barrier protecting cells from the outside environment and if the nanoparticles can cross this barrier they may go into cells.’

‘Dr Jean-Baptiste Fleury (from Saarland University in Germany) designed a special set-up with two chambers separated by a lipid bilayer, which contained fluorescent lipids (fat molecules). Non-fluorescent nanoparticles were added to only one of the chambers. In this set-up, nanoparticles became visible only when they touched the fluorescent bilayer and exchanged lipids with it. If one sees the fluorescent nanoparticle in the second chamber, this means it was in contact with the bilayer and it crossed the bilayer from one chamber to another. This was the proof. In addition, the process of translocation was quantified and the time of the crossing was estimated as milliseconds.’

All biological objects, biomolecules, proteins that exist in living organisms evolved over billions of years to adapt to each other. Nanoparticles which are synthesised in the laboratory are thus considered by a living organism as something foreign. It is a big challenge to make them compatible and not toxic.’ ‘I would count the applications of nanoparticles as starting from the 1985 Nobel Prize for the discovery of fullerenes (molecules of hollow football-shaped carbon). This was the start of the nanoparticle boom.’

This is becoming urgent because nanoparticles and nanotechnology in general are entering our lives. Now it is possible to synthesise nanomaterials with precise control, fabricate nanostructures on surfaces and do precise tailoring of the properties of nanoparticles.

‘It is becoming quite urgent to understand the exact mechanisms of nanotoxicity and make a classification depending on the mechanism. Radioactivity or X-rays entered our lives the same way. It took time until researchers understood the mechanisms of action on living organisms and the regulations evolved with our understanding.’

gold nanoparticles cross the membrane

This is the first observation to show directly how tiny gold nanoparticles can cross a lipid bilayer.

An empirical test of toxicity is that you put nanoparticles into the cells and you see the cells are dead, but you don’t understand what has happened, this is empirical. This is a legitimate tool, but it is not enough to address toxicity. Instead, one could start from the properties of nanoparticles and think about classifying nano-objects based on their physical or chemical properties by trying to predict the effect of a given nanoparticle on a cell or tissue beforehand.

I understand, it may look too ambitious, since there are a lot of tiny details that are not considered at the moment in theoretical models or any classification. However, even if it may not be exact, it can give some guidance and it would be possible to make predictions on how nanoparticles and polymers interact with lipid membranes. For example, in this study we used theoretical modelling to suggest the size and surface properties of the nanoparticle that is able to cross the lipid membrane through a certain pathway and it was observed experimentally.’


Nanoparticles And Immunotherapy, Allies To Eradicate Cancer

Some researchers are working to discover new, safer ways to deliver cancer-fighting drugs to tumors without damaging healthy cells. Others are finding ways to boost the body’s own immune system to attack cancer cells. Researchers at Pennsylvania State University   (Penn State) have combined the two approaches by taking biodegradable polymer nanoparticles encapsulated with cancer-fighting drugs and incorporating them into immune cells to create a smart, targeted system to attack cancers of specific types.


The traditional way to deliver drugs to tumors is to put the drug inside some type of nanoparticle and inject those particles into the bloodstream,” said Jian Yang, professor of biomedical engineering, Penn State. “Because the particles are so small, if they happen to reach the tumor site they have a chance of penetrating through the blood vessel wall because the vasculature of tumors is usually leaky.”

The odds of interacting with cancer cells can be improved by coating the outside of the nanoparticles with antibodies or certain proteins or peptides that will lock onto the cancer cell when they make contact. However, this is still a passive drug delivery technology. If the particle does not go to the tumor, there is no chance for it to bind and deliver the drug.

Yang and Cheng Dong, professor of biomedical engineering, wanted a more active method of sending drugs to the cancer wherever it was located, whether circulating in the blood, the brain, or any of the other organs of the body.

“I have 10 years of working in immunology and cancer,” Dong said. “Jian is more a biomaterials scientist. He knows how to make the nanoparticles biodegradable. He knows how to modify the particles with surface chemistry, to decorate them with peptides or antibodies. His material is naturally fluorescent, so you can track the particles at the same time they are delivering the drug, a process called theranostics that combines therapy and diagnostics. On the other hand, I study the cancer microenvironment, and I have discovered that the microenvironment of the tumor generates kinds of inflammatory signals similar to what would happen if you had an infection.”

Immune cells, which were built to respond to inflammatory signals, will be naturally attracted to the tumor site. This makes immune cells a perfect active delivery system for Yang’s nanoparticles. The same technology is also likely to be effective for infectious or other diseases, as well as for tissue regeneration, Dong said.


How To Stop The Spread Of Breast Cancer

A breakthrough technology that harnesses manmade nanoparticles could one day become an important new weapon in the fight against cancer. The technique, which appeared to successfully stop the spread of breast cancer in mice, was unveiled by scientists from the Cold Spring Harbor Laboratory, Dana-Farber Cancer Institute, Stony Brook University, and a host of other research institutions in the journal Science Translational Medicine.

Next-generation cancer fighting therapies on the market today use the body’s immune system to combat tumors, as does experimental technology like CRISPR gene-editing. But the new nanotech has a different target: The cells that actually help cancer metastasize and spread throughout the body. These immune cells, which are meant to ward off infections, create structures called neutrophil extracellular traps (NETs) that help them fight bacteria. But NETs can actually wind up helping spread the cancer by creating tissue openings that cancerous cells can exploit, study co-author Mikala Egeblad explained.


A high magnification of an intact neutrophil (yellow arrow) and a NET (white arrow)

So the researchers created a new particle coated with a special enzyme that can kill these cells before the cancer can use them to metastasize. The results were modest, but promising: Three out of the nine mice given the nanoparticle showed no evidence of breast cancer progression, while all mice in the control group continued to worsen.

Wave Of Destruction In Cancer Cells

Nanoparticles known as Cornell dots, or C dots, have shown great promise as a therapeutic tool in the detection and treatment of cancer.

Now, the ultrasmall particles – developed more than a dozen years ago by Ulrich Wiesner, the Spencer T. Olin Professor of Engineering at Cornell University – have shown they can do something even better: kill cancer cells without attaching a cytotoxic drug.

The study was led by Michelle Bradbury, director of intraoperative imaging at Memorial Sloan Kettering Cancer Center (MSKCC) and associate professor of radiology at Weill Cornell Medicine, and Michael Overholtzer, cell biologist at MSKCC, in collaboration with Wiesner. Their work details how C dots, administered in large doses and with the tumors in a state of nutrient deprivation, trigger a type of cell death called ferroptosis.


If you had to design a nanoparticle for killing cancer, this would be exactly the way you would do it,” Wiesner said. “The particle is well tolerated in normally healthy tissue, but as soon as you have a tumor, and under very specific conditions, these particles become killers.”

In fact,” Bradbury said, “this is the first time we have shown that the particle has intrinsic therapeutic properties.