#New material opens possibilities for super-long-acting pills Medical devices designed to reside in the stomach have a variety of applications,
However, these devices, often created with nondegradable elastic polymers, bear an inherent risk of intestinal obstruction as a result of accidental fracture or migration.
Now, researchers at MIT Koch Institute for Integrative Cancer Research and Massachusetts General Hospital (MGH) have created a polymer gel that overcomes this safety concern
This polymer is ph-responsive: It is stable in the acidic stomach environment but dissolves in the small intestine near-neutral ph,
allowing for safe passage through the remainder of the gastrointestinal (GI TRACT. The material is also elastic,
allowing for the compression and folding of devices into easily ingestible capsules meaning this polymer can be used to create safe devices designed for extremely prolonged residence in the stomach. ne of the issues with any device in the GI TRACT is that there the potential for an obstruction,
which is a medical emergency potentially requiring surgical intervention, says Koch Institute research affiliate Giovanni Traverso,
also a gastroenterologist at MGH and an instructor at Harvard Medical school. material like this represents a real advance
because it is both safe and stable in the stomach environment. Traverso and Robert Langer, the David H. Koch Institute Professor at MIT and a member of the Koch Institute, are the senior authors of a paper in the issue of Nature Materials that describes the application of this new
polymer gel for creating gastric devices. Shiyi Zhang, a postdoc at the Koch Institute, is the paper lead author.
Safely stretching Designing devices for the stomach is complicated a matter of sizes and shapes. The stomach naturally empties its contents in a matter of hours
so for devices to be retained, they must be wider than the pylorus the valve at the end of the stomach, about 1. 5 to 2 centimeters in diameter,
the researchers were interested in developing a polymer with elastic properties. n elastic device can be folded into something small,
But the size and shape of existing devices with elastic polymers have been limited by safety concerns,
as there is a greater risk for fracture if a device is too large or too complex.
Because of this, the researchers wanted their polymer to also be enteric or have a mechanism that would enable it to pass through the stomach unaltered before disintegrating in the intestines. o lower any possible risk of obstruction,
the researchers synthesized an elastic polymer and combined it in solution with a clinically utilized enteric polymer.
Adding hydrochloric acid and centrifuging the solution resulted in a flexible, yet resilient, polymer gel that exhibits both elastic and enteric properties.
The researchers used the gel polycaprolactone (PCL), a nontoxic, degradable polyester, to construct several device prototypes.
They first created ring-shaped devices by using the gel to link arcs of PCL in a circular mold.
In testing the capsules in pigs, the researchers found that the rings expanded into their original shape within 15 minutes of ingestion
the polymer gel dissolved, allowing for the safe passage of the small PCL pieces without obstruction.
and delivered through the esophagus with the assistance of an endoscope. These devices remained in the stomach for up to five days, after
Improving adherence The combined enteric and elastic properties of this polymer gel could significantly improve the design and adoption of gastric-resident devices.
ingestible electronics, which can diagnose and monitor a variety of conditions in the GI TRACT; or extended-release drug-delivery systems that could last for weeks
a professor of medical science and engineering at Brown University who was not involved with this study. his is a very smart approach.
With further work in adjusting the polymer composition or the design of the system they say that they could tailor devices to release drugs over a specific timeframe of up to weeks or months at a time.
MIT is negotiating an exclusive license agreement with Lyndra, an early-stage biotechnology company developing novel oral drug-delivery systems,
patientsadherence to long-term therapies for chronic illnesses is only 50 percent in developed countries, with lower rates of adherence in developing nations.
Medication nonadherence costs the U s. an estimated $100 billion every year, the bulk of which comes in the form of unnecessary hospitalizations.
The researchers also say that single-administration delivery systems for the radical treatment of malaria
and other infections could significantly benefit from these technologies. Source: MIT, written by Kevin Leonard e
A nanoscale view of the new superfast fluorescent system using a transmission electron microscope. The silver cube is just 75-nanometers wide.
The quantum dots (red) are sandwiched between the silver cube and a thin gold foil. At its most basic level, your smart phone battery is powering billions of transistors using electrons to flip on and off billions of times per second.
But if microchips could use photons instead of electrons to process and transmit data, computers could operate even faster.
But first engineers must build a light source that can be turned on and off that rapidly.
While lasers can fit this requirement, they are too energy-hungry and unwieldy to integrate into computer chips.
Duke university researchers are now one step closer to such a light source. In a new study, a team from the Pratt School of engineering pushed semiconductor quantum dots to emit light at more than 90 gigahertz.
This so-called plasmonic device could one day be used in optical computing chips or for optical communication between traditional electronic microchips. his is something that the scientific community has wanted to do for a long time,
said Maiken Mikkelsen, an assistant professor of electrical and computer engineering and physics at Duke. e can now start to think about making fast-switching devices based on this research, so there a lot of excitement about this demonstration. leb Akselrod, Maiken Mikkelsen,
and Thang Hoangthe new speed record was set using plasmonics. When a laser shines on the surface of a silver cube just 75 nanometers wide,
the free electrons on its surface begin to oscillate together in a wave. These oscillations create their own light,
which reacts again with the free electrons. Energy trapped on the surface of the nanocube in this fashion is called a plasmon.
The plasmon creates an intense electromagnetic field between the silver nanocube and a thin sheet of gold placed a mere 20 atoms away.
This field interacts with quantum dotspheres of semiconducting material just six nanometers widehat are sandwiched in between the nanocube and the gold.
The quantum dots, in turn, produce a directional, efficient emission of photons that can be turned on and off at more than 90 gigahertz. here is great interest in replacing lasers with LEDS for short-distance optical communication,
but these ideas have always been limited by the slow emission rate of fluorescent materials, lack of efficiency and inability to direct the photons,
said Gleb Akselrod, a postdoctoral research in Mikkelsen laboratory. ow we have made an important step towards solving these problems. n illustration of the new superfast fluorescent system.
The silver nanocube sits on top of a thin gold foil, with red quantum dots sandwiched between. he eventual goal is to integrate our technology into a device that can be excited either optically
or electrically, said Thang Hoang, also a postdoctoral researcher in Mikkelsen laboratory. hat something that I think everyone,
including funding agencies, is pushing pretty hard for. he group is now working to use the plasmonic structure to create a single photon source necessity for extremely secure quantum communicationsy sandwiching a single quantum dot in the gap between the silver nanocube and gold foil.
They are also trying to precisely place and orient the quantum dots to create the fastest fluorescence rates possible.
Aside from its potential technological impacts the research demonstrates that well-known materials need not be limited by their intrinsic properties. y tailoring the environment around a material,
like wee done here with semiconductors, we can create new designer materials with almost any optical properties we desire,
said Mikkelsen. nd that an emerging area that fascinating to think about. ource: Duke Universit a
#In CRISPR Advance, Scientists Successfully Edit Human T cells In a project spearheaded by investigators at UC San francisco,
scientists have devised a new strategy to precisely modify human T cells using the genome-editing system known as CRISPR/Cas9.
Because these immune-system cells play important roles in a wide range of diseases, from diabetes to AIDS to cancer, the achievement provides a versatile new tool for research on T cell function,
as well as a path toward CRISPR/Cas9-based therapies for many serious health problems. Using their novel approach,
the scientists were able to disable a protein on the T-cell surface called CXCR4, which can be exploited by HIV
a protein that has attracted intense interest in the burgeoning field of cancer immunotherapy, as scientists have shown that using drugs to block PD-1 coaxes T cells to attack tumors.
The CRISPR/Cas9 system has captured the imagination of both scientists and the general public, because it makes it possible to easily
and inexpensively edit genetic information in virtually any organism. T cells, which circulate in the blood, are an obvious candidate for medical applications of the technology,
as these cells not only stand at the center of many disease processes, but could be gathered easily from patients,
edited with CRISPR/Cas9, then returned to the body to exert therapeutic effects. But in practice, editing T cell genomes with CRISPR/Cas9 has proved surprisingly difficult,
said Alexander Marson, Phd, a UCSF Sandler Fellow, and senior and co-corresponding author of the new study. enome editing in human T cells has been a notable challenge for the field,
Marson said. o we spent the past year and a half trying to optimize editing in functional T cells.
There are a lot of potential therapeutic applications and we want to make sure wee driving this as hard as we can.
The new work was done under the auspices of the Innovative Genomics Initiative (IGI), a joint UC Berkeley-UCSF program co-directed by Berkeley Jennifer Doudna, Phd,
and Jonathan Weissman, Phd, professor of cellular and molecular pharmacology at UCSF and a Howard hughes medical institute (HHMI) investigator.
Doudna, professor of chemistry and of cell and molecular biology at Berkeley, and an HHMI investigator,
said that the research is a significant step forward in bringing the power of CRISPR/Cas9 editing to human biology
and medicine. t been great to be part of this exciting collaboration, and I look forward to seeing the insights from this work used to help patients in the future,
said Doudna, co-corresponding author of the new paper. Cas9, an enzyme in the CRISPR system that makes cuts in DNA
and allows new genetic sequences to be inserted, has generally been introduced into cells using viruses or circular bits of DNA called plasmids.
(or nock in specific new sequences to correct mutations in T cells. As will be reported online in Proceedings of the National Academy of Sciences during the week of July 27
and eventually for therapeutic use. e tried for a long time to introduce Cas9 with plasmids or lentiviruses,
He hopes that Cas9-based therapies for T cell-related disorders, which include autoimmune diseases as well as immunodeficiencies such as ubble boy disease,
will enter the clinic in the future. here actually well-trodden ground putting modified T cells into patients.
There are companies out there already doing it and figuring out the safety profile, so there increasing clinical infrastructure that we could potentially piggyback on as we work out more details of genome editing,
Marson said. think CRISPR-edited T cells will eventually go into patients, and it would be wrong not to think about the steps we need to take to get there safely and effectively.
#Tiny grains of rice hold big promise for greenhouse gas reductions, bioenergy Discovery delivers high starch content,
but it also the one of the largest manmade sources of atmospheric methane, a potent greenhouse gas.
such as starch for a richer food source and biomass for energy production, according to a study in Nature.
resulting in a plant that can better feed its grains, stems and leaves while starving off methane-producing microbes in the soil.
represent a culmination of more than a decade of work by researchers in three countries, including Christer Jansson, director of plant sciences at the Department of energy Pacific Northwest National Laboratory and EMSL, DOE Environmental Molecular Sciences Laboratory.
Jansson and colleagues hypothesized the concept while at the Swedish University of Agricultural sciences and carried out ongoing studies at the university
and with colleagues at China Fujian Academy of Agricultural sciences and Hunan Agricultural University. he need to increase starch content and lower methane emissions from rice production is recognized widely
but the ability to do both simultaneously has eluded researchers, Jansson said. s the world population grows, so will rice production.
and leaves increases their mass and creates more plant biomass, a bioenergy feedstock. In early work in Sweden, Jansson and his team investigated how distribution of sugars in plants could be controlled by a special protein called a transcription factor,
which binds to certain genes and turns them on or off. y controlling where the transcription factor is produced,
we can then dictate where in a plant the carbon and resulting sugars accumulate, Jansson said.
As such, SUSIBA2 had the ability to direct the majority of carbon to the grains and leaves
Over three years of field studies in China, researchers consistently demonstrated that SUSIBA2 delivered increased crop yields and a near elimination of methane emissions f
#Speedy crystal sponges to clean up waste Close up of the metal organic framework crystals. New sponge-like crystals that clean up contaminants in industrial waste
and soil can now be made rapidly and for 30 per cent of the cost. CSIRO new method, developed in collaboration with The University of Padova (Italy)
and The University of Adelaide, makes the crystals viable to manufacture for the first time by reducing the production time from up to two days down to as few as 15 minutes.
The crystals are made of extremely porous metal organic frameworks (MOFS) and have an internal storage capacity of 7,
000 square metres, which is equal to the size of a football oval in a single gram.
This means that the crystals can filter huge volumes of industrial wastewater, trapping large amounts of contaminants including carcinogenic material and heavy metals.
CSIRO research team leader, Dr Paolo Falcaro, said the length of time it takes to produce MOFS has been a barrier to their manufacture until now. ee estimated that this process could cut the cost to make MOFS by thousands of dollars for Australian manufacturers,
Dr Falcaro said. hile wee initially used the method to create zinc oxide-based MOFS, it could be applied to a range of different MOFS with applications spanning energy and pharmaceuticals.
SIRO Dr Paolo Falcaro has developed a rapid and cost-effective way to grow metal organic frameworksproducing MOF crystals has traditionally been an energy-intensive process due to the heating and cooling required,
but this new method is performed at room temperature for dramatic energy savings. ee now seeking to work with Australian chemical manufacturers to further develop the method
and explore turning the crystals into a sustainable industrial waste management product, Dr Falcaro said. CSIRO has used already MOFS to develop a molecular shell to protect
and deliver drugs and vaccines, a olar spongethat can capture and release carbon dioxide emissions andplastic material that gets better with age.
Source: CSIR r
#Researchers demonstrate the world first white lasers While lasers were invented in 1960 and are used commonly in many applications,
one characteristic of the technology has proven unattainable. No one has been able to create a laser that beams white light.
Researchers at Arizona State university have solved the puzzle. They have proven that semiconductor lasers are capable of emitting over the full visible color spectrum,
which is necessary to produce a white laser. The researchers have created a novel nanosheet a thin layer of semiconductor that measures roughly one-fifth of the thickness of human hair in size with a thickness that is roughly one-thousandth of the thickness of human hair with three
parallel segments each supporting laser action in one of three elementary colors. The device is capable of lasing in any visible color, completely tunable from red, green to blue,
The researchers, engineers in ASU Ira A. Fulton Schools of Engineering, published their findings in the online publication of the journal Nature Nanotechnology.
Cun-Zheng Ning, professor in the School of Electrical, Computer and Energy Engineering, authored the paper, monolithic white laser, with his doctoral students Fan Fan, Sunay Turkdogan, Zhicheng Liu
The technological advance puts lasers one step closer to being a mainstream light source and potential replacement or alternative to light emitting diodes (LEDS.
and can potentially provide more accurate and vivid colors for displays like computer screens and televisions.
Ning group has shown already that their structures could cover as much as 70 percent more colors than the current display industry standard.
which the same room lighting systems could be used for both illumination and communication. The technology under development is called Li-Fi for light-based wireless communication,
as opposed to the more prevailing Wi-fi using radio waves. Li-Fi could be more than 10 times faster than current Wi-fi
and white laser Li-Fi could be 10 to 100 times faster than LED based Li-Fi currently still under development. he concept of white lasers first seems counterintuitive
because the light from a typical laser contains exactly one color, a specific wavelength of the electromagnetic spectrum, rather than a broad-range of different wavelengths.
who also spent extended time at Tsinghua University in China during several years of the research.
In typical LED-based lighting a blue LED is coated with phosphor materials to convert a portion of the blue light to green, yellow and red light.
This mixture of colored light will be perceived by humans as white light and can therefore be used for general illumination.
The researchers showed that the human eye is as comfortable with white light generated by diode lasers as with that produced by LEDS,
those independent lasers cannot be used for room lighting or in displays, Ning said. single tiny piece of semiconductor material emitting laser light in all colors
or in white is desired. Semiconductors, usually a solid chemical element or compound arranged into crystals, are used widely for computer chips or for light generation in telecommunication systems.
They have interesting optical properties and are used to make lasers and LEDS because they can emit light of a specific color
when a voltage is applied to them. The most preferred light emitting material for semiconductors is indium gallium nitride
though other materials such as cadmium sulfide and cadmium selenide also are used for emitting visible colors. The main challenge, the researchers noted, lies in the way light emitting semiconductor materials are grown
and how they work to emit light of different colors. Typically a given semiconductor emits light of a single color blue,
green or red that is determined by a unique atomic structure and energy bandgap. The attice constantrepresents the distance between the atoms.
To produce all possible wavelengths in the visible spectral range you need several semiconductors of very different lattice constants
and energy bandgaps. ur goal is to achieve a single semiconductor piece capable of laser operation in the three fundamental lasing colors.
The piece should be small enough so that people can perceive only one overall mixed color,
instead of three individual colors, said Fan. ut it was not easy. he key obstacle is called an issue lattice mismatch,
or the lattice constant being too different for the various materials required, Liu said. e have not been able to grow different semiconductor crystals together in high enough quality,
using traditional techniques, if their lattice constants are too different. The most desired solution, according to Ning, would be to have a single semiconductor structure that emits all needed colors.
He and his graduate students turned to nanotechnology to achieve their milestone. The key is that at nanometer scale larger mismatches can be tolerated better than in traditional growth techniques for bulk materials.
High quality crystals can be grown even with large mismatch of different lattice constants. Recognizing this unique possibility early on,
Ning group started pursuing the distinctive properties of nanomaterials, such as nanowires or nanosheets, more than 10 years ago.
He and his students have been researching various nanomaterials to see how far they could push the limit of advantages of nanomaterials to explore the high crystal quality growth of very dissimilar materials.
Six years ago, under U s army Research Office funding, they demonstrated that one could indeed grow nanowire materials in a wide range of energy bandgaps
so that color tunable lasing from red to green can be achieved on a single substrate of about one centimeter long.
Later on they realized simultaneous laser operation in green and red from a single semiconductor nanosheet or nanowires.
These achievements triggered Ning thought to push the envelope further to see if a single white laser is ever possible.
proved to be a greater challenge with its wide energy bandgap and very different material properties. e have struggled for almost two years to grow blue emitting materials in nanosheet form,
which is required to demonstrate eventual white lasers, said Turkdogan, who is now assistant professor at University of Yalova in Turkey.
After exhaustive research, the group finally came up with a strategy to create the required shape first
and then convert the materials into the right alloy contents to emit the blue color.
and an important breakthrough that finally made it possible to grow a single piece of structure containing three segments of different semiconductors emitting all needed colors and the white lasers possible.
One of crucial next steps is to achieve the similar white lasers under the drive of a battery.
#Scientists create functional liver cells from stem cells Major implications for liver biology and drug discovery The liver plays a critical role in human metabolism.
Evaluating this drug-induced liver injury is a critical part of pharmaceutical drug discovery and must be carried out on human liver cells.
in research published on the cover of the July edition of Hepatology, scientists from the Hebrew University of Jerusalem Alexander Grass Center for Bioengineering report that they produced large amounts of functional liver cells from human
The groundbreaking work further demonstrated that liver cells produced from either embryonic stem cells or genetically engineered skin cells,
can detect the toxic effect of over a dozen drugs with greater than 97%accuracy. he implications for liver biology
Oren Shibolet, Head of the Liver Unit at the Tel-aviv Sourasky Medical center, who was involved not in this study. he method provides access to unlimited amounts of functional liver cells
and is likely to critically improve our ability to predict drug toxicity, which was limited previously by the unavailability of liver cells.
The data presented suggest that parents abstaining from this practice may cause liver maturation and drug metabolism in their children to develop quiet differently. n
#Nonsurgical approach helps people with paralysis voluntarily move their legs In a study conducted at UCLA,
It is believed to be the first time voluntary leg movements have ever been relearned in completely paralyzed patients without surgery.
The results are reported in the Journal of Neurotrauma. hese findings tell us we have to look at spinal cord injury in a new way,
said V. Reggie Edgerton, senior author of the research and a UCLA distinguished professor of integrative biology and physiology,
neurobiology and neurosurgery. Edgerton said although it likely will be years before the new approaches are widely available,
he now believes that it is possible to significantly improve quality of life for patients with severe spinal cord injuries,
because youe not going to recover function below the lesion, 'he said. hey have been told that for decades,
Edgerton and colleagues, the University of Louisville Susan Harkema and Claudia Angeli and UCLA Yury Gerasimenko, reported that four young men who had been paralyzed for years were able to move their legs, hips,
along with Ruslan Gorodnichev of Russia Velikie Luky State Academy of Physical education and Sport, demonstrated that they could induce involuntary stepping movements in healthy,
The finding led Edgerton to believe the same approach could be effective for people with complete paralysis. In the new research,
a drug often used to treat anxiety disorders. Researchers placed electrodes at strategic points on the skin, at the lower back and near the tailbone and then administered a unique pattern of electrical currents.
The electrical charges caused no discomfort to the patients who were lying down. he fact that they regained voluntary control so quickly must mean that they had neural connections that were dormant,
who for nearly 40 years has conducted research on how the neural networks in the spinal cord regain control of standing,
stepping and voluntary control of movements after paralysis. t was said remarkable. dgerton most experts, including himself, had assumed that people who were paralyzed completely would no longer have had neural connections across the area of the spinal cord injury.
The researchers do not know yet whether patients who are paralyzed completely can be trained to fully bear their weight and walk.
But he and colleagues have published now data on nine people who have regained voluntary control of their legs our with epidural implants
and when the subjects see their legs moving for the first time after paralysis, they say it a big deal. he men in the newest study ranged in age from 19 to 56;
their injuries were suffered during athletic activities or, in one case, in an auto accident. All have been paralyzed completely for at least two years.
The research was funded by the National institutes of health National Institute of Biomedical Imaging and Bioengineering (grants U01eb15521 and R01eb007615), the Christopher and Dana Reeve Foundation,
the Walkabout Foundation and the Russian Scientific Fund. hese encouraging results provide continued evidence that spinal cord injury may no longer mean a lifelong sentence of paralysis
and support the need for more research, said Dr. Roderic Pettigrew, director of the National Institute of Biomedical Imaging and Bioengineering. he potential to offer a life-changing therapy to patients without requiring surgery would be a major advance;
it could greatly expand the number of individuals who might benefit from spinal stimulation. It a wonderful example of the power that comes from combining advances in basic biological research with technological innovation. dgerton estimates that cost to patients of the new approach could be one-tenth the cost of treatment using the surgical epidural stimulator
(which is also still experimental) and, because no surgery is required, it would likely be more easily available to more patients.
The study co-authors were conceived Gerasimenko, who the new approach and is director of the laboratory of movement physiology at Russia Pavlov Institute and a researcher in the UCLA department of integrative biology and physiology,
as well as Daniel Lu, associate professor of neurosurgery, researchers Morteza Modaber, Roland Roy and Dimitry Sayenko, research technician Sharon Zdunowski, research scientist Parag Gad, laboratory
coordinator Erika Morikawa and research assistant Piia Haakana, all of UCLA; and Adam Ferguson, assistant professor of neurological surgery at UC San francisco. Edgerton and his research team also plan to study people who have severe,
but not complete, paralysis. heye likely to improve even more, he said. The scientists can only work with a small number of patients, due to limited resources,
but Edgerton is optimistic that the research can benefit many others. Almost 6 million Americans live with paralysis,
including nearly 1. 3 million with spinal cord injuries. person can have hope, based on these results,
Edgerton said. n my opinion, they should have hope. s
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