Posts belonging to Category biomolecular

Photovoltaics: Light Absorption Enhanced by Up to 200 Percent

Sunlight reflected by solar cells is lost as unused energy. The wings of the butterfly Pachliopta aristolochiae are drilled by nanostructures (nanoholes) that help absorbing light over a wide spectrum far better than smooth surfaces. Researchers of Karlsruhe Institute of Technology (KIT) in Germany, have now succeeded in transferring these nanostructures to solar cells and, thus, enhancing their light absorption rate by up to 200 percent.

 “The butterfly studied by us is very dark black. This signifies that it perfectly absorbs sunlight for optimum heat management. Even more fascinating than its appearance are the mechanisms that help reaching the high absorption. The optimization potential when transferring these structures to photovoltaics (PV) systems was found to be much higher than expected,” says Dr. Hendrik Hölscher of KIT’s Institute of Microstructure Technology (IMT).


The scientists of the team of Hendrik Hölscher and Radwanul H. Siddique (formerly KIT, now Caltech) reproduced the butterfly’s nanostructures in the silicon absorbing layer of a thin-film solar cell. Subsequent analysis of light absorption yielded promising results: Compared to a smooth surface, the absorption rate of perpendicular incident light increases by 97% and rises continuously until it reaches 207% at an angle of incidence of 50 degrees. “This is particularly interesting under European conditions. Frequently, we have diffuse light that hardly falls on solar cells at a vertical angle,” Hendrik Hölscher says. However, this does not automatically imply that efficiency of the complete PV system is enhanced by the same factor, says Guillaume Gomard of IMT. “Also other components play a role. Hence, the 200 percent are to be considered a theoretical limit for efficiency enhancement.

The scientists have reported their results in the journal Science Advances. (DOI: 10.1126/sciadv.1700232.)


How To Correct Genes That Cause High Cholesterol

U.S. researchers have used nanotechnology plus the powerful CRISPR-Cas9 gene-editing tool to turn off a key cholesterol-related gene in mouse liver cells, an advance that could lead to new ways to correct genes that cause high cholesterol and other liver diseasesNanotechnology is the design and manipulation of materials thousands of times smaller than the width of a human hair.

We’ve shown you can make a nanoparticle that can be used to permanently and specifically edit the DNA in the liver of an adult animal,” said study author Daniel Anderson, an associate professor in chemical engineering at the Massachusetts Institute of Technology.

The study, published  in Nature Biotechnology, holds promise for permanently editing genes such as PCSK9, a cholesterol-regulating gene that is already the target of two drugs made by the biotechnology companies Regeneron Pharmaceuticals and Amgen.

In the study, the scientists were trying to develop a safe and efficient way to deliver the components needed for CRISPR-Cas9, a type of molecular scissors that can selectively trim away defective genes and replace them with new stretches of DNA.

The system consists of a DNA-cutting enzyme called Cas9 and a stretch of RNA that guides the cutting enzyme to the correct spot in the genome. Most teams currently use viruses to deliver CRISPR into cells, an approach that is limited because the immune system can develop antibodies to viruses.

To overcome this, the team chemically modified the CRISPR components to protect them from enzymes in the body that would normally break them down. They then inserted this material into nano-scale fat particles and injected them into mice, where they made their way to liver cells.

In tests targeting the PCSK9 gene, the system proved highly effective, . The PCSK9 protein made by this gene was undetectable in the treated mice, eliminating the gene in more than 80 percent of liver cells, which also experienced a 35 percent drop in total cholesterol, the researchers reported.

High levels of cholesterol can clog arteries, causing reduced blood flow that can lead to a heart attack or stroke.


New Genetic And Stem-Cell Technology To Grow Sheets Of Skin

Somewhere in Germany’s Ruhr valley, a nine-year-old boy is doing what children do: playing football, joking around with friends and going to school. Two years ago, he was confined to a hospital bed, dying of a rare and cruel genetic skin disease. The boy had junctional epidermolysis bullosa, or JEB. He, like other people with the disease, carried a mutation in a gene that controls the integrity of the skin. Doctors could only try to ease his suffering as some 80% of his skin simply fell away.

A team of Italian researchers came to his aid by combining stem-cell techniques with gene therapy. As a young scientist at Harvard Medical School in Boston, Massachusetts, in the 1980s, Michele De Luca — the lead author of the new study — watched pioneers in skin regeneration learn to grow small sheets of skin from cells taken from burns patients, and to use them in grafts. He extended the work in Italy, applying new genetic and stem-cell technologies. He developed ways to generate stem cells from human skin, replace disease-causing genes in them and grow sheets of healthy skin on scaffolds in the lab.

He chose JEB for his first clinical trial, which he registered with the Italian Medicines Agency in 2002. Four years later, he reported his first success, in which he created healthy skin patches from biopsies to replace small areas of sloughed-off skin on the legs of a patient with a form of JEB (F. Mavilio et al. Nature Med. 12, 1397–1402; 2006). New European Commission regulations introduced in 2007 required him to pause the project while he created facilities adhering to ‘good manufacturing practices’ (GMPs) and a spin-off company to meet the demands for strengthened oversight of cell-based therapies.

Having a company refocused his team’s attention on a different type of stem-cell therapy, one likely to yield a product for the market faster. Holoclar, a treatment that replaces the eye’s cornea in a form of blindness, became the world’s first commercial stem-cell therapy in 2015.

A few months later, at the University of Modena, De Luca got a call out of the blue from doctors in Germany who were trying to treat the little boy. Because the therapy had been in a clinical trial, albeit one on hold at the time, and because De Luca could provide GMP services, German regulatory authorities quickly approved the one-off compassionate use of the JEB therapy. Surgeons in Germany sent a skin biopsy to Modena, and two major skin transplants followed. Six months after the initial biopsy, the boy returned to school. During the many months since, he has not had so much as a blister, and loves to show off his ‘new skin’. By their nature, highly personalized treatments using gene therapies and products derived from an individual’s stem cells are likely to be applicable to only a subset of patients.

Scientists and clinicians have presented the details of the recovery in Nature (T. Hirsch et al.Nature; 2017). This major clinical development was based on decades of basic research. The clinical data gathered during 21 months of follow-up after the boy’s treatment have also led to major insights into human skin biology, as discussed in an accompanying News & Views (M. Aragona and C. Blanpain Nature; 2017). For example, normal regeneration of the epidermis is directed by only a few stem-cell clones that can self-renew.


Nanocompounds Enhance Microbial Activity On Soil, Enrich Crops

We live in a world where day to day objects seems to be getting smaller and better. The advent of nanotechnology is a major contributing factor to this phenomenon. Defined as the “engineered construction of matter at the molecular level”, nanotechnology has applications and uses in a multitude of fields. From medicine, electronics, food, clothing, batteries and environment, nanotechnology seems to be pushing the limits of all these fields. Now, scientist have discovered yet another novel application of nanotechnologyfacilitating soil microbial growth.

Indian scientists from the G. B. Pant University of Agriculture and Technology, Pantnangar, Indian Veterinary Research Institute, Izatnagar, and State Council for Science & Technology, Dehradun, studied the impact of three nanocompounds on soil microbial activity and the health of plants being cultivated.

The scientists found that supplementing agricultural soils with nanocompounds like nanoclay, nanochitosan and nanozeolite led to a higher growth of microbial populations in the soil. And such an increased microbial population further led to increased levels of phosphorus, organic carbon and nitrogen in the soils, all of which are known to improve the health of crops being cultivated. Additionally, the scientists also observed increased levels of microbial enzyme activity in the soil, as well as a 50% rise in the total protein content of the soil.

Although nanoclay had the least effect on the soil’s pH, nanozeolite was found to best facilitate the growth of soil microbes. An increase in soil microbial activity along with all the other downstream benefits, caused by these nanocompounds, are all an indicator of enhanced soil health. Therefore, supplementing soils with such nanocompounds could go a long way in improving the agricultural soils, plant health and ultimately, the crop yields of the country.


Acupuncture And Nanotechnology Married To Cure Cancer

DGIST (Daegu Gyeongbuk Institute of Science and Technology) in South Korea announced that Professor Su-Il In’s research team from the department of Energy Science and Engineering has presented the possibility of cancer treatment, including colorectal cancer, using acupuncture needles that employ nanotechnology for the first time in the world.

The research team of Professor Su-Il In, through joint research with Dr. Eunjoo Kim of Companion Diagnostics & Medical Technology Research Group at DGIST and Professor Bong-Hyo Lee’s research team from the College of Oriental Medicine at Daegu Haany University, has published a study showing that the molecular biologic indicators related to anticancer effects are changed only by the treatment of acupuncture, which is widely used in oriental medicine.

In oriental medicine, treatment using acupuncture needles has been commonly practiced for thousands of years in the fields of treating musculoskeletal disorders, pain relief, and addiction relief. Recently, it has emerged as a promising treatment for brain diseases, gastrointestinal disorders, nausea, and vomiting, and studies are under way to use acupuncture to treat severe diseases.


Not only that, Professor In’s team discovered that acupuncture needles can be used for cancer treatment which is difficult to treat in modern medicine. In this study, the researchers developed nanoporous needles with microscopic holes in the surface of the needles ranging from nanopores (nm = one billionth of a meter) to micrometers (μm = one millionth of a meter) by applying relatively simple electrochemical nanotechnology. By increasing the surface area of the needle by a factor of ten, the nanoporous needles doubled the electrophysiological signal generation function by needle stimulus.

As a result of AOM administration in rats, the rats receiving periodic acupuncture treatment with nanoporous needles were found to have a much lower incidence of abnormal vascular clusters as a precursor to colorectal cancer in the initiation stage than those in the control group.


Editing Genes In Human Embryos

Two new CRISPR tools overcome the scariest parts of gene editing.The ability to edit RNA and individual DNA base pairs will make gene editing much more precise. Several years ago, scientists discovered a technique known as CRISPR/Cas9, which allowed them to edit DNA more efficiently than ever before.
Since then, CRISPR science has exploded; it’s become one of the most exciting and fast-moving areas of research, transforming everything from medicine to agriculture and energy. In 2017 alone, more than 14,000 CRISPR studies were published.

But here’s the thing: CRISPR, while a major leap forward in gene editing, can still be a blunt instrument. There have been problems with CRISPR modifying unintended gene targets and making worrisome, and permanent, edits to an organism’s genome. These changes could be passed down through generations, which has raised the stakes of CRISPR experiments — and the twin specters of “designer babies” and genetic performance enhancers — particularly when it comes to editing genes in human embryos.
So while CRISPR science is advancing quickly, scientists are still very much in the throes of tweaking and refining their toolkit. And on Wednesday, researchers at the Broad Institute of MIT and Harvard launched a coordinated blitz with two big reports that move CRISPR in that safer and more precise direction.
In a paper published in Science, researchers described an entirely new CRISPR-based gene editing tool that targets RNA, DNA’s sister, allowing for transient changes to genetic material. In Nature, scientists described how a more refined type of CRISPR gene editing can alter a single bit of DNA without cutting it — increasing the tool’s precision and efficiency.

The first paper, out Wednesday in Science, describes a new gene editing system. This one, from researchers at MIT and Harvard, focuses on tweaking human RNA instead of DNA.

Our cells contain chromosomes made up of chemical strands called DNA, which carry genetic information. Those genes have recipes for proteins that lead to a bunch of different traits. But to carry out the instructions in any one recipe, DNA needs another type of genetic material called RNA to get involved.

RNA is ephemeral: It acts like a middleman, or a messenger. For a gene to become a protein, that gene has to be transcribed into RNA in the cell, and the RNA is then read to make the protein. If the DNA is permanent — the family recipe book passed down through generations — the RNA is like your aunt’s scribbled-out recipe on a Post-It note, turning up only when it’s needed and disappearing again.

With the CRISPR/Cas9 system, researchers are focused on editing DNA. (For more on how that system works, read this Vox explainer.) But the new Science paper describes a novel gene editing tool called REPAIR that’s focused on using a different enzyme, Cas13, to edit that transient genetic material, the RNA, in cells. REPAIR can target specific RNA letters, or nucleosides, that are involved in single-base changes that regularly cause disease in humans.

This is hugely appealing for one big reason: With CRISPR/Cas9, the changes to the genome, or the cell’s recipe book, are permanent. You can’t undo them. With REPAIR, since researchers can target single bits of ephemeral RNA, the changes they make are transient, even reversible. So this system could fix genetic mutations without actually touching the genome (like throwing away your aunt’s Post-It note recipe without adding it to the family recipe book).


How To Detect Lead In Water

Gitanjali Rao, 11-year-old girl, is “America’s Top Young Scientist” of this year, with her invention of Tethys, a device that detects lead in water.


Tethys, the Greek goddess of fresh water, is a lead detection tool. What you do is first dip a disposable cartridge, which can easily be removed and attached to the core device in the water you wish to test. Once you do that, that’s basically the manual part. Then you just pull out an app on your phone and check your status and it looks like the water in this container is safe. So that’s just very simple, about like a 10 to 15 second process,” says Gitanjali Rao . The young girl was affected by the Flint, Michigan water catastrophe when the city started using the Flint River for water in 2014, sparking a crisis that was linked to an outbreak of Legionnaires’ disease, at least 12 deaths and dangerously high lead levels in children.

I was most affected about Flint, Michigan because of the amount of people that were getting affected by the lead in water. And I also realized that it wasn’t just in Flint, Michigan and there were over 5,000 water systems in the U.S. alone. In the beginning of my final presentation at the event, I talked about a little boy named Opemipo, he’s 10 years old and lives in Flint, Michigan. And he has 1 percent elevated lead levels in his blood. And he’s among the thousands of adults and children exposed to the harmful effects of lead in water. So it’s a pretty big deal out there today,” remembers Rao. The seventh-grader said it took her five months to make Tethys from start to finish.

My first couple of times when I was doing my experimentation and test, I did fail so many times and it was frustrating, but I knew that it was just a learning experience and I could definitely develop my device further by doing even more tests and getting advice from my mentor as well. So, never be afraid to try,” explains Rao, who  won the 2017 Discovery Education 3M Young Scientist Challenge, along with a $25,000 prize.


Self-regulating Nanoparticles Treat Cancer

Scientists from the University of Surrey have developed ‘intelligentnanoparticles which heat up to a temperature high enough to kill cancerous cells – but which then self-regulate and lose heat before they get hot enough to harm healthy tissue. The self-stopping nanoparticles could soon be used as part of hyperthermic-thermotherapy to treat patients with cancer, according to an exciting new study reported in NanoscaleThermotherapy has long been used as a treatment method for cancer, but it is difficult to treat patients without damaging healthy cells. However, tumour cells can be weakened or killed without affecting normal tissue if temperatures can be controlled accurately within a range of 42°C to 45°C.

Scientists from Surrey’s Advanced Technology Institute have worked with colleagues from the Dalian University of Technology in China to create nanoparticles which, when implanted and used in a thermotherapy session, can induce temperatures of up to 45°C. The Zn-Co-Cr ferrite nanoparticles produced for this study are self-regulating, meaning that they self-stop heating when they reach temperatures over 45°C. Importantly, the nanoparticles are also low in toxicity and are unlikely to cause permanent damage to the body.

This could potentially be a game changer in the way we treat people who have cancer. If we can keep cancer treatment sat at a temperature level high enough to kill the cancer, while low enough to stop harming healthy tissue, it will prevent some of the serious side effects of vital treatment. It’s a very exciting development which, once again, shows that the University of Surrey research is at the forefront of nanotechnologies – whether in the field of energy materials or, in this case, healthcare,” said Professor Ravi Silva, Head of the Advanced Technology Institute at the University of Surrey.

Dr. Wei Zhang, Associate Professor from Dalian University of Technology explains: “Magnetic induced hyperthermia is a traditional route of treating malignant tumours. However, the difficulties in temperature control has significantly restricted its usage If we can modulate the magnetic properties of the nanoparticles, the therapeutic temperature can be self-regulated, eliminating the use of clumsy temperature monitoring and controlling systems.

“By making magnetic materials with the Curie temperature falling in the range of hyperthermia temperatures, the self-regulation of therapeutics can be achieved. For the most magnetic materials, however, the Curie temperature is much higher than the human body can endure. By adjusting the components as we have, we have synthesized the nanoparticles with the Curie temperature as low as 34oC. This is a major nanomaterials breakthrough.”


Using Brain-Machine Interfaces, Mental Power Can Move Objects

A unique citizen science project in which volunteers will be trained to move a piece of steel machinery using the power of their mind begins on October 27. The Mental Work project uses brain-machine interfaces developed at EPFL (Ecole polytechnique fédérale de Lausanne) in Switzerland, a convergence of science, art, and design .


At the mental work factory the public can come and we equip them with an EEG helmet which will read the mental activity, the electrical activity, that’s in their brain. These helmets are dry, so we don’t need gel for conductivity and they’re also wireless so they can walk through the mental factory and engage with four of our machines activating them with only their mental activity,  explains Michael Mitchell , who is one of the three co-founders of Mental Work.

The data that will be collected during the mental worker’s trajectory throughout our factory floor will then be made anonymous and given to the brain machine interface community to improve the interfaces for the future. “We think that we’re on the cusp of a cognitive revolution. Now a cognitive revolution is going to be a world where our brains are intimately connected to our physical world around us. With the development of these brain machine interfaces we think that we are really at the beginning of a moment in time where man is going to become the centre of all this technology. His brain activity is going to interact with the physical world around him in ways that we can hardly imagine today. “So I think it’s understandable if people are a little apprehensive about this technology because some people may think ‘oh, it can read my thoughts and then what are we going to do with those thoughts. Where’s the privacy level here?’ But in fact we’re only asking you to modulate your brain activity according to your own will. So it’s as simple as sending a command to a computer using a mouse or a keyboard. But this time we’re using asking you to use your brain. Now we want to bring this technology to the public at a early phase of its development so that we can create a dialogue about what kind of relationship we want to have with this technology in particular but also with man’s relationship to technology in general.


Gene Researchers Have Created Green Mice

These are no Frankenstein mice. Their green feet come courtesy of a fluorescent green jelly fish gene added to their own genome. This allows a team of British scientists to test out gene editing using CRISPR-Cas9 technology.


“We take what were or would have been green embryos and we make them into non-green embryos, so it’s a really great way of demonstrating the method“, said Dr. Anthony Perry, reproductive biologist at the University of Bath.

The technique uses the ribonucleic acid molecule CRISPR together with the Cas9 protein enzyme. CRISPR guides the Cas9 protein to a defective part of a genome where it acts like molecular scissors to cut out a specific part of the DNA. This could revolutionise how we treat diseases with a genetic component, like sickle cell anaemia. The technique is being pioneered in the U.S.
We now have a technology that allows correction of a sequence that would lead to normally functioning cells. And I think you know the opportunities with this are really exciting and really profound. There are many diseases that are have known genetic causes that we now have in principle a way to cure,“explains Jennifer Doudna, Professor of cell biology at the University of Berkeley.
Last year two teams of U.S. based scientists used CRISPR-Cas9 technology in mice to correct the genetic mutation that causes sickle cell disease. Although researchers aren’t yet close to using CRISPR-Cas9 to edit human embryos for implantation into the womb – some are already warning against it.

Dr David King, Director of  Human Genetics Alert, comments: “It will immediately create this new form of what we call consumer eugenics, that’s to say eugenics driven by the free market and consumer preferences in which people choose the cosmetic characteristics and the abilities of their children and try to basically enhance their children to perform better than other people’s children.” Other potential applications of the technology could be to make food crops and livestock animal species disease-resistant. The British team say CRISPR-Cas9 presents a golden opportunity to prevent genetic disease.


How To Track Blood Flow In Tiny Vessels

Scientists have designed gold nanoparticles, no bigger than 100 nanometres, which can be coated and used to track blood flow in the smallest blood vessels in the body. By improving our understanding of blood flow in vivo the nanoprobes represent an opportunity to help in the early diagnosis of diseaseLight microscopy is a rapidly evolving field for understanding in vivo systems where high resolution is required. It is particularly crucial for cardiovascular research, where clinical studies are based on ultrasound technologies which inherently have lower resolution and provide limited information.

The ability to monitor blood flow in the sophisticated vascular tree (notably in the smallest elements of the microvasculaturecapillaries) can provide invaluable information to understand disease processes such as thrombosis and vascular inflammation. There are further applications for the improved delivery of therapeutics, such as targeting tumours.

Currently, blood flow in the microvasculature is poorly understood. Nanoscience is uniquely placed to help understand the processes happening in the micron-dimensioned vessels. Designing probes to monitor blood flow is challenging because of the environment; the high protein levels in plasma and the high red blood cell concentrations are detrimental to optical imaging. Conventional techniques rely on staining red blood cells, using organic dyes with short-lived usage due to photobleaching, as the tracking motif. The relatively large size of the red blood cells (7-8 micrometres), which are effectively the probes, limits the resolution in imaging and analysis of flow dynamics of the smallest vessels which are of a similar width. Therefore, to have more detailed resolution and information about the blood flow in the microvasculature, even smaller probes are required.

The key to these iridium-coated nanoparticles lies in both their small size, and in the characteristic luminescent properties. The iridium gives a luminescent signal in the visible spectrum, providing an optical window which can be detected in blood. It is also long-lived compared to organic fluorophores, while the tiny gold particles are shown to be ideal for tracking flow and detect clearly in tissues“, explains Professor Zoe Pikramenou, from the School of Chemistry at  the University of Birmingham.

The findings have been published in the journal Nanomedicine.


How To Fix Duchenne Muscular Dystrophy

Scientists at the University of California, Berkeley, have engineered a new way to deliver CRISPR-Cas9 gene-editing technology inside cells and have demonstrated in mice that the technology can repair the mutation that causes Duchenne muscular dystrophy, a severe muscle-wasting disease. A new study shows that a single injection of CRISPR-Gold, as the new delivery system is called, into mice with Duchenne muscular dystrophy led to an 18-times-higher correction rate and a two-fold increase in a strength and agility test compared to control groups.

Since 2012, when study co-author Jennifer Doudna, a professor of molecular and cell biology and of chemistry at UC Berkeley, and colleague Emmanuelle Charpentier, of the Max Planck Institute for Infection Biology, repurposed the Cas9 protein to create a cheap, precise and easy-to-use gene editor, researchers have hoped that therapies based on CRISPR-Cas9 would one day revolutionize the treatment of genetic diseases. Yet developing treatments for genetic diseases remains a big challenge in medicine. This is because most genetic diseases can be cured only if the disease-causing gene mutation is corrected back to the normal sequence, and this is impossible to do with conventional therapeutics.

CRISPR/Cas9, however, can correct gene mutations by cutting the mutated DNA and triggering homology-directed DNA repair. However, strategies for safely delivering the necessary components (Cas9, guide RNA that directs Cas9 to a specific gene, and donor DNA) into cells need to be developed before the potential of CRISPR-Cas9-based therapeutics can be realized. A common technique to deliver CRISPR-Cas9 into cells employs viruses, but that technique has a number of complications. CRISPR-Gold does not need viruses.

In the new study, research lead by the laboratories of Berkeley bioengineering professors Niren Murthy and Irina Conboy demonstrated that their novel approach, called CRISPR-Gold because gold nanoparticles are a key component, can deliver Cas9 – the protein that binds and cuts DNA – along with guide RNA and donor DNA into the cells of a living organism to fix a gene mutation.

CRISPR-Gold is the first example of a delivery vehicle that can deliver all of the CRISPR components needed to correct gene mutations, without the use of viruses,” Murthy said.

The study was published in the journal Nature Biomedical Engineering.