Articles from August 2014

Could Nanotechnology Kill Ebola?

The Ebola virus out­break in West Africa has claimed more than 1200 lives since Feb­ruary and has infected thou­sands more. Coun­tries such as Nigeria and Liberia have declared health emer­gen­cies, while the World Health Orga­ni­za­tion dis­cuss ways to battle the outbreak. There is no known vac­cine, treat­ment, or cure for Ebola, which is con­tracted through the bodily fluids of an infected person or animal. But that doesn’t mean there’s not hope. In fact, Chem­ical Engi­neering Chair Thomas Webster’s lab (NorthEastern University) is cur­rently working on one pos­sible solu­tion for fighting Ebola and other deadly viruses: nanotechnology.
It has been very hard to develop a vac­cine or treat­ment for Ebola or sim­ilar viruses because they mutate so quickly,” explained Web­ster, the editor-​​in-​​chief of the Inter­na­tional Journal of Nanomed­i­cine. “In nan­otech­nology we turned our atten­tion to devel­oping nanopar­ti­cles that could be attached chem­i­cally to the viruses and stop them from spreading.
One par­ticle that is showing great promise is gold. According to Web­ster, gold nanopar­ti­cles are cur­rently being used to treat cancer. Infrared waves, he explained, heat up the gold nanopar­ti­cles, which, in turn, attack and destroy every­thing from viruses to cancer cells, but not healthy cells.

Rec­og­nizing that a larger sur­face area would lead to a quicker heat-​​up time, Webster’s team cre­ated gold nanos­tars. “The star has a lot more sur­face area, so it can heat up much faster than a sphere can,” Web­ster said. “And that greater sur­face area allows it to attack more viruses once they absorb to the par­ti­cles.” In addi­tion to the gold nanos­tars, Webster’s lab is also gen­er­ating a nanopar­ticle that would serve as a “virus decoy,” chem­i­cally attracting the virus to attack it rather than healthy cells.


Liver Cancer: Hope Is Coming From Plants

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-associated death worldwide. Also called malignant hepatoma, HCC is the most common type of liver cancer. Most cases of HCC are secondary to either a viral hepatitis infection (hepatitis B or C) or cirrhosis (alcoholism being the most common cause of hepatic cirrhosis). These regrettably poor prognoses are due to the difficulty in treating this cancer using conventional chemotherapeutic drugs such as doxorubicin, epirubicin, cisplatin, 5-fluorouracil, etoposide or combinations therein. This may be attributed to that the conventional medicines are not able to reach in a sufficient concentration in the liver tumor cells at levels that are not harmful to the rest of the body.

Now a team of scientists, led by Prof. Taeghwan Hyeon at the Institute for Basic Science (IBS)/Seoul National University and Prof. Kam Man Hui at the National Cancer Center Singapore, has screened a library containing hundreds of natural products against a panel of HCC cells to search a better drug candidate. The screen uncovered a compound named triptolide, a traditional Chinese medicine isolated from the thunder god vine (Tripterygium wilfordii (Latin) or lei gong teng (Chinese)) which was found to be far more potent than current therapies. Studies from other researchers corroborate the findings as triptolide has also found to be very effective against several other malignant cancers including; pancreatic, neuroblastoma and cholangiocarcinoma. However this excitement was tempered when the drug was administered to mice as the increased potency was coupled with increased toxicity as well. Prof. Hyeon et al. endeavoured to alleviate the toxic burden by increasing the specific delivery of the drug to the tumor using a nanoformulation. The designed formulation was a pH-sensitive nanogel coated with the nucleotide precursor, folate.

Defect-Free Graphene For Electric Car Batteries

Researchers at from Korea’s KAIST institute developed a new method to fabricate defect-free graphene. Using this graphene, they developed a promising high-performance anode for Li-Ion batteries. Graphene has already been demonstrated to be useful in Li-ion batteries, despite the fact that the graphene used often contains defects. Large-scale fabrication of graphene that is chemically pure, structurally uniform, and size-tunable for battery applications has so far remained elusive. Now in a new study, scientists have developed a method to fabricate defect-free graphene (df-G) without any trace of structural damage. Wrapping a large sheet of negatively charged df-G around a positively charged Co3O4 creates a very promising anode for high-performance Li-ion batteries.
electric car

The research groups of Professor Junk-Ki Park and Professor Hee-Tak Kim from Korea Advanced Institute of Science and Technology (KAIST) and Professor Yong-Min Lee’s research group from Hanbat National University, all in Daejeon, South Korea, have published their paper on the new fabrication method in a recent issue of Nano Letters.


Medical Nanorobots

Researchers from the Institute of General Physics, the Institute of Bioorganic Chemistry (Russia, Academy of Sciences) and MIPT have made an important step towards creating medical nanorobots. They discovered a way of enabling nano– and microparticles to produce logical calculations using a variety of biochemical reactions.
biological nanorobotsThe scientists draw on the idea of computing using biomolecules. In electronic circuits, for instance, logical connectives use current or voltage (if there is voltage, the result is 1, if there is none, it’s 0). In biochemical systems, the result can a given substance. For example, modern bioengineering techniques allow for making a cell illuminate with different colors or even programming it to die, linking the initiation of apoptosis to the result of binary operations.

Scientists say logical operations inside cells to be a way of controlling biological processes and creating nano-robots, which can deliver drugs on schedule. Calculations using biomolecules inside cells, a.k.a. biocomputing, are a very promising and rapidly developing branch of science, according to the leading author of the study, Maxim Nikitin, a 2010 graduate of MIPT’s Department of Biological and Medical Physics. Biocomputing uses natural cellular mechanisms.

The study paves the way for a number of biomedical technologies and differs significantly from previous works in biocomputing binary operations in DNA, RNA and proteins for over a decade now, but Maxim Nikitin and his colleagues were the first to propose and experimentally confirm a method to transform almost any type of nanoparticle or microparticle into autonomous biocomputing structures that are capable of implementing a functionally complete set of Boolean logic gates (YES, NOT, AND and OR) and binding to a target (such as a cell) as result of a computation.

The prefix “nano” in this case is not a fad or a mere formality. A decrease in particle size sometimes leads to drastic changes in the physical and chemical properties of a substance. The smaller the size, the greater the reactivity; very small semiconductor particles, for example, may produce fluorescent light. The new research project used nanoparticles (i.e. particles of 100 nm) and microparticles (3000 nm or 3 micrometers).

The new work was published on the website of the journal Nature Nanotechnology.

Sunblocks Are Toxic For Aquatic Life

The sweet and salty aroma of sunscreen and seawater signals a relaxing trip to the shore. But scientists from the Université Aix-Marseille, France, are now reporting that the idyllic beach vacation comes with an environmental hitch. When certain sunblock ingredients wash off skin and into the sea, they can become toxic to some of the ocean’s tiniest inhabitants, which are the main course for many other marine animals.

Antonio Tovar-Sanchez and David Sánchez-Quiles (IMERAUniversité Aix Marseille) point out that other than staying indoors, slathering on sunscreen is currently the best way to protect skin from the sun’s harmful rays. But when sunbathers splash into the ocean to cool off, some of their lotions and creams get rinsed into the water. The problem is that titanium dioxide and zinc oxide nanoparticles, which are common ingredients in sunblock, can react with ultraviolet light from the sun and form new compounds, such as hydrogen peroxide, that could be toxic. High amounts of hydrogen peroxide can harm phytoplankton, the microscopic algae that feed everything from small fish to shrimp to whales. The scientists wanted to figure out just how serious of an impact beachgoers could be having on life in coastal waters.

To investigate the matter, they hit the beach. They went to Majorca Island’s Palmira beach on the Mediterranean along with about 10,000 beachgoers, a small portion of the more than 200 million tourists that flock to Mediterranean shores every year. Based on lab tests, seawater sampling and tourism data, the researchers concluded that titanium dioxide from sunblock was largely responsible for a dramatic summertime spike in hydrogen peroxide levels in coastal waters — with potentially dangerous consequences for aquatic life.


How To Inhibit Cancer Cells Growth

Small RNA molecules, including microRNAs (miRNAs) and small interfering RNAs (siRNAs), offer tremendous potential as new therapeutic agents to inhibit cancer-cell growth. However, delivering these small RNAs to solid tumors remains a significant challenge, as the RNAs must target the correct cells and avoid being broken down by enzymes in the body. To date, most work in this area has focused on delivery to the liver, where targeting is relatively straightforward.
This week in the journal Proceedings of the National Academy of Sciences, researchers at the Koch Institute for Integrative Cancer Research at MIT report that they have successfully delivered small RNA therapies in a clinically relevant mouse model of lung cancer to slow and shrink tumor growth. Their research offers promise for personalized RNA combination therapies to improve therapeutic response.This mouse model reflects many of the hallmarks of human lung cancer and is often used in preclinical trials. It was originally developed in the laboratory of Koch Institute Director Tyler Jacks, the David H. Koch Professor of Biology, who is co-senior author of the research paper. This early example of RNA combination therapy demonstrates the potential of developing personalized cancer treatments. With efficient delivery of therapeutic RNA, any individual small RNA or combination of RNAs could be deployed to regulate the genetic mutations underlying a given patient’s cancer.

nanoparticles deliver RNAMIT engineers designed nanoparticles that can deliver short strands of RNA (green) into cells (nuclei are stained blue).
RNA therapies are very flexible and have a lot of potential, because you can design them to treat any type of disease by modifying gene expression very specifically,” says James Dahlman, a graduate student in Anderson’s and Langer’s laboratories who, along with senior postdoc Wen Xue of Jacks’ laboratory, is co-first author of the paper. “We took the best mouse model for lung cancer we could find, we found the best nanoparticle we could use, and for one of the first times, we demonstrate targeted RNA combination therapy in a clinically relevant model of lung cancer.”


How Cancer Cells Invade The Body

Using a nanocomputer that acts as an obstacle course for cells, researchers from the Brown School of Engineering have shed new light on a cellular metamorphosis thought to play a role in tumor cell invasion throughout the body.

The epithelial-mesenchymal transition (EMT) is a process in which epithelial cells, which tend to stick together within a tissue, change into mesenchymal cells, which can disperse and migrate individually. EMT is a beneficial process in developing embryos, allowing cells to travel throughout the embryo and establish specialized tissues. But recently it has been suggested that EMT might also play a role in cancer metastasis, allowing cancer cells to escape from tumor masses and colonize distant organs.

For this study, published in the journal Nature Materials, the researchers were able to image cancer cells that had undergone EMT as they migrated across a device that mimics the tissue surrounding a tumor.
emt pillarsBenign cancer cells that had been induced to become malignant made their way slowly around microscopic obstacles. About 16 percent of the cells moved much more rapidly across the microchip
People are really interested in how EMT works and how it might be associated with tumor spread, but nobody has been able to see how it happens,” said lead author Ian Wong, assistant professor in the Brown School of Engineering and the Center for Biomedical Engineering, who performed the research as a postdoctoral fellow at Massachusetts General Hospital. “We’ve been able to image these cells in a biomimetic system and carefully measure how they move.”


Computer: Nano Optical Cables To Replace Copper

Electrical engineers design nano-optical cables that could replace copper wiring on computer chips. The invention of fibre optics revolutionized the way we share information, allowing us to transmit data at volumes and speeds we’d only previously dreamed of. Now, electrical engineering researchers at the University of Alberta are breaking another barrier, designing nano-optical cables small enough to replace the copper wiring on computer chips. This could result in radical increases in computing speeds and reduced energy use by electronic devices. A new step towards the nanocomputer era.

We’re already transmitting data from continent to continent using fibre optics, but the killer application is using this inside chips for interconnect—that is the Holy Grail,” says Zubin Jacob, an electrical engineering professosr leading the research. “What we’ve done is come up with a fundamentally new way of confining light to the nano scale.
At present, the diameter of fibre optic cables is limited to about one thousandth of a millimetre. Cables designed by graduate student Saman Jahani and Jacob are 10 times smaller—small enough to replace copper wiring still used on computer chips. (To put that into perspective, a dime is about one millimetre thick.)


Cancer: How To Boost Immune Cells

Scientists at Yale University have developed a novel cancer immunotherapy that rapidly grows and enhances a patient’s immune cells outside the body using carbon nanotube-polymer composites; the immune cells can then be injected back into a patient’s blood to boost the immune response or fight cancer.

The researchers used bundled carbon nanotubes (CNTs) to incubate cytotoxic T cells, a type of white blood cell that is important to immune system functions. According to the researchers, the topography of the CNTs enhances interactions between cells and long-term cultures, providing a fast and effective stimulation of the cytotoxic T cells that are important for eradicating cancer.

cancer-helfA high-resolution, scanning electron microscope image of the carbon nanotube-polymer composite. The bundled CNTs appear as spaghetti-like structures.
In repressing the body’s immune response, tumors are like a castle with a moat around it,” says Tarek Fahmy, an associate professor of biomedical engineering and the study’s principal investigator. “Our method recruits significantly more cells to the battle and arms them to become superkillers.”
The findings ae reported Aug. 3 in Nature Nanotechnology.


Fast DNA Sequencing Under A Thousand Dollars

Gene-based personalized medicine has many possibilities for diagnosis and targeted therapy, but one big bottleneck: the expensive and time-consuming DNA-sequencing process. Now, researchers at the University of Illinois at Urbana-Champaign have found that nanopores in the material molybdenum disulfide (MoS2) could sequence DNA more accurately, quickly and inexpensively than anything yet available.
One of the big areas in science is to sequence the human genome for under $1,000, the ‘genome-at-home,’” said Narayana Aluru, a professor of mechanical science and engineering at the U. of I. who led the study. “There is now a hunt to find the right material. We’ve used MoS2 for other problems, and we thought, why don’t we try it and see how it does for DNA sequencing?” As it turns out, MoS2 outperforms all other materials used for nanopore DNA sequencing – even graphene.
A nanopore is a very tiny hole drilled through a thin sheet of material. The pore is just big enough for a DNA molecule to thread through. An electric current drives the DNA through the nanopore, and the fluctuations in the current as the DNA passes through the pore tell the sequence of the DNA, since each of the four letters of the DNA alphabet – A, C, G and T – are slightly different in shape and size.

DNA through nanopores

A DNA molecule passes through a nanopore in a sheet of molybdenum disulfide, a material that researchers have found to be better than graphene at reading the DNA sequence
The ultimate goal of this research is to make some kind of home-based or personal DNA sequencing device,” Barati Farimani said. “We are on the path to get there, by finding the technologies that can quickly, cheaply and accurately identify the human genome. Having a map of your DNA can help to prevent or detect diseases in the earliest stages of development. If everybody can cheaply sequence so they can know the map of their genetics, they can be much more alert to what goes on in their bodies.


New Nanoparticles Destroy Brain Cancer

A “Trojan horse” treatment for an aggressive form of brain cancer, which involves using tiny nanoparticles of gold to kill tumour cells, has been successfully tested by scientists from the University of Cambridge (U.K)

The ground-breaking technique could eventually be used to treat glioblastoma multiforme, which is the most common and aggressive brain tumour in adults, and notoriously difficult to treat. Many sufferers die within a few months of diagnosis, and just six in every 100 patients with the condition are alive after five yearsThe research involved engineering nanostructures containing both gold and cisplatin, a conventional chemotherapy drug. These were released into tumour cells that had been taken from glioblastoma patients and grown in the lab.

Once inside, these “nanospheres” were exposed to radiotherapy. This caused the gold to release electrons which damaged the cancer cell’s DNA and its overall structure, thereby enhancing the impact of the chemotherapy drug.

gold nanoparticle against brain cancer

The combined therapy that we have devised appears to be incredibly effective in the live cell culture,” Professor Welland said. “This is not a cure, but it does demonstrate what nanotechnology can achieve in fighting these aggressive cancers. By combining this strategy with cancer cell-targeting materials, we should be able to develop a therapy for glioblastoma and other challenging cancers in the future”.

The process was so effective that 20 days later, the cell culture showed no evidence of any revival, suggesting that the tumour cells had been destroyed.


How To Reset Sleep

Scientists at the Salk Institute for Biological Studies have identified a gene that regulates sleep and wake rhythms.

The discovery of the role of this gene, called Lhx1, provides scientists with a potential therapeutic target to help night-shift workers or jet lagged travelers adjust to time differences more quickly. The results, published in eLife, can point to treatment strategies for sleep problems caused by a variety of disorders.

Every cell in the body has a “clock” – an abundance of proteins that dip or rise rhythmically over approximately 24 hours. The master clock responsible for establishing these cyclic circadian rhythms and keeping all the body’s cells in sync is the suprachiasmatic nucleus (SCN), a small, densely packed region of about 20,000 neurons housed in the brain’s hypothalamus.

pepside in the brain

A peptide responsible for cell communication in the brain, Vip (green) is reduced in the brains of mice that have little or no Lhx1 (right)

No one had ever imagined that Lhx1 might be so intricately involved in SCN function,” says Shubhroz Gill, a postdoctoral researcher and co-first author of the paper. Lhx1 is known for its role in neural development: it’s so important, that mice without the gene do not survive. But this is the first time it has been identified as a master regulator of light-dark cycle genes. “It’s possible that the severity of many dementias comes from sleep disturbances,” says Satchidananda Panda, a Salk associate professor who led the research team. “If we can restore normal sleep, we can address half of the problem.”