#Scientists Demonstrate Intrinsic Chirality in Ordinary Nanocrystals By Stuart Milnethese findings have opened new possibilities in medicine,
biotechnology and nanobiotechnology for applications including targeted drug delivery. Chirality of an object is its property that allows it to be non-superimposable with its mirror image.
Ever since the development of artificial nanocrystals, scientists thought that chirality was either random or completely absent in nanocrystals.
Researchers from Trinity college Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), partnered with collaborators from ITMO University Optics of Quantum Nanostructures laboratory in a joint experiment to show that standard nanocrystals were made up a 50:50
mixture of'left'and'right'chiral forms. Standard nanocrystals are composed of cadmium selenide quantum dots and quantum rods.
Artificial chiral nanocrystals can be produced by fastening special chiral ligand molecules to the nanocrystal surface.
In the natural world, chirality is an inherent property of many objects that range from spiral galaxies to elementary particles.
The human body is composed of chiral biomolecules. Many other biological objects are composed also of these chiral biomolecules.
In these compounds, the'left'form may be significantly different from the'right'form. Among these forms, usually one form is beneficial,
which could be medical benefits, while the other form, which is its antipode, would be useless.
Ibuprofen is used a widely painkiller and its molecules possess two optical mirror isomers. One of these isomers is beneficial
while the other is toxic and does not relieve pain. The optical activity is considered to be an important indicator of chiral environment.
It has the ability to rotate the polarized light plane to the left or right, depending upon the nanocrystal chiral form.
Theoretically, optical activity is observed not in any normal nanocrystal solution. The absence of chirality in nanocrystals has been considered to be the cause of optical activity.
In this study, the researchers have proved the opposite, by dividing the nanocrystal'left'and'right'forms.
Yurii Gun'ko, professor at Trinity college and co-director of International Research and Education Centre for Physics of Nanostructures at ITMO University comments on potential applications of the method developed by the group:
The scientists developed a technique for separating various forms of nanocrystals and also capture their intrinsic chirality manifestation.
This technique could possibly be expanded and then used with various other inorganic nanomaterials. In an unmixable two-phase solution composed of an organic solvent (chloroform) and water,
nanocrystals were immersed. Nanocrystals do not dissolve in water; hence L-cysteine was added to transfer the nanocrystals in organic phase to water.
L-cysteine is a chiral molecule and it is used widely for phase transfers as a ligand.
Nanocrystals have hydrophobic ligands on their surface, and cysteine replaces these ligands and makes the material soluble in water.
Hence, all the nanocrystals will be in water, irrespective of the cysteine chiral form. When this solution was cooled
and the phase transfer was interrupted at a specific point, a particular situation where the nanocrystal ensemble was divided equally between the phases that had nanocrystals both'left'and'right'-in different phases.
Furthermore removal of cysteine does not affect the nanocrystal optical activity due to this separation. This provides more proof to the existence of intrinsic chirality in nanocrystals.
Vladimir G. Maslov, Anatoly V. Fedorov, Alexander V. Baranov, Finn Purcell-Milton, Anna O. Orlova,
and Joseph Govan were other researchers who took part in this study. The research team has published their study titled,'Intrinsic chirality of Cdse/Zns quantum dots and quantum rods,'in Nano Letters e
#Placenta-on-a-Chip Helps Study Inner Workings of Human Placenta The study, published online in the Journal of Maternal-Fetal & Neonatal Medicine,
was conducted by an interdisciplinary team of researchers from the NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the University of Pennsylvania, Wayne State university/Detroit Medical center
, Seoul National University and Asan Medical center in South korea.""We believe that this technology may be used to address questions that are difficult to answer with current placenta model systems
and help enable research on pregnancy and its complications,"said Roberto Romero, M d.,chief of the NICHD's Perinatology Research Branch and one of the study authors.
The placenta is a temporary organ that develops in pregnancy and is the major interface between mother and fetus.
Among its many functions is to serve as a"crossing guard"for substances traveling between mother and fetus.
The placenta helps nutrients and oxygen move to the fetus and helps waste products move away.
The researchers created the placenta-on-a-chip technology to address these challenges, using human cells in a structure that more closely resembles the placenta's maternal-fetal barrier.
the researchers tested its function by evaluating the transfer of glucose (a substance made by the body when converting carbohydrates to energy) from the maternal compartment to the fetal compartment.
"The chip may allow us to do experiments more efficiently and at a lower cost than animal studies,"said Dr. Romero."
#Polymer Nanobrushes Grab Selected Bacteria for Pathogen Detection A Texas A&m Agrilife Research engineer and a Florida colleague have developed a biosensor that can detect listeria bacterial contamination within two
"said Dr. Carmen Gomes, Agrilife Research engineer with the Texas A&m University department of biological and agricultural engineering, College Station.
The same technology can be developed to detect other pathogens such as E coli O157: H7, she said.
But listeria was chosen as the first target pathogen because it can survive even at freezing temperatures.
It is also one of the most common foodborne pathogens in the world and the third-leading cause of death from food poisoning in the U s."It can grow under refrigeration,
but it will grow rapidly when it is warmed up as its optimum growth temperature ranges from 30 to 37 degrees Celsius--86 to 98 degrees Fahrenheit,
fruits and soft cheeses that are stored under refrigeration.""Currently, the only means of detecting listeria bacteria contamination of food requires highly trained technicians
For food processing companies that produce and ship large quantities of foodstuff daily, listeria contamination sources can be a moving target that is often missed by current technology.
but in a few years she envisions a hand-held device that will require hardly any training to use.
Gomes is collaborating with Dr. Eric Mclamore at the University of Florida at Gainesville.""I do the biological and polymer engineering;
he does the electrochemistry and nanostructures, "she said. As for the biological component, Gomes said she is using"nanobrushes"specially designed to grab particular bacteria.
The nanobrushes utilize"aptamers, "which are single stranded-dna DNA or RNA molecules that bind to the receptors on the target organism's cell outer membrane,
Gomes said. This"binding"is compared often to the way a key fits into only one Lock in this manner,
which in the case of her work is the listeria bacterium. Gomes noted that the inspiration for the nanobrushes comes from the Hawaiian bobtail squid
"To predators, the bioluminescence is very similar to the light coming from the moon and stars at night,
"The selection process the polymers use to select for specific bacteria in the listeria biosensor is very similar to the squid's cilia.
when the polymer nanobrushes have had time to grab the selected bacteria, the rest of the sample is washed away and the impedance,
Gomes and Mclamore are moving on to refining the electronics to something that can be handheld and easily used.
Also in the works is a disposable paper-based biosensor that can be disposed of after one use.
000 National Science Foundation grant to continue their work on nanobrushes for pathogen detection n
#Nano-Packaged Drug Can Halt and Reverse Progression of Atherosclerosis in Rodents In what may be a major leap forward in the quest for new treatments of the most common form of cardiovascular disease,
scientists at Johns Hopkins report they have found a way to halt and reverse the progression of atherosclerosis in rodents by loading microscopic nanoparticles with a chemical that restores the animals'ability to properly handle cholesterol.
Cholesterol is a fatty substance that clogs, stiffens and narrows the blood vessels, greatly diminishing their ability to deliver blood to the heart muscle and the brain.
known as atherosclerotic vessel disease, is the leading cause of heart attacks and strokes that claim some 2. 6 million lives a year worldwide, according to the World health organization.
A report on the work, published online in the journal Biomaterials, builds on recent research by the same team that previously identified a fat-and-sugar molecule called GSL as the chief culprit behind a range of biological glitches that affect the body's ability to properly use, transport
and purge itself of vessel-clogging cholesterol. That earlier study showed that animals feasting on high-fat foods remained free of heart disease if pretreated with a man-made compound
D-PDMP, which works by blocking the synthesis of the mischievous GSL. But the body's natural tendency to rapidly break down
and clear out D-PDMP was a major hurdle in efforts to test its therapeutic potential in larger animals and humans.
The newly published report reveals the scientists appear to have cleared that hurdle by encapsulating D-PDMP into tiny molecules,
but not potent enough to stop the disease from advancing. Perhaps, most importantly, the team says,
and pumping dysfunction, the hallmarks of advanced disease.""Our experiments illustrate clearly that while content is important,
"says lead investigator Subroto Chatterjee, Ph d.,a professor of medicine and pediatrics at the Johns hopkins university School of medicine and a metabolism expert at its Heart and Vascular Institute."
and its ability not merely to prevent disease but to mitigate some of its worst manifestations."
and track the nanoparticles'movement inside the animals'bodies by tagging them with a radioactive tracer that lit up on a CT SCAN.
D-PDMP treatment improved heart function in mice with advanced forms of atherosclerotic heart disease, marked by heart muscle thickening
Because the nanoparticles carrying D-PDMP are made of a common laxative ingredient and a naturally occurring sebacic acid,
#New Method to See Inside Supercapacitors at the Atomic Level By using a combination of nuclear magnetic resonance (NMR) spectroscopy
the researchers were able to visualise how ions move around in a supercapacitor. They found that
while charging, different processes are at work in the two identical pieces of carbon pongewhich function as the electrodes in these devices, in contrast to earlier computer simulations.
Supercapacitors are used in applications where quick charging and power delivery are important, such as regenerative braking in trains and buses, elevators and cranes.
They are used also in flashes in mobile phones and as a complementary technology to batteries in order to boost performance.
For example, when placed alongside a battery in an electric car, a supercapacitor is useful when a short burst of power is required,
such as when overtaking another car, with the battery providing the steady power for highway driving. upercapacitors perform a similar function to batteries
but at a much higher power they charge and discharge very quickly, said Dr John Griffin, a postdoctoral researcher in the Department of chemistry,
and the paper lead author. heye much better at absorbing charge than batteries, but since they have much lower density,
they hold far less of that charge, so theye not yet a viable alternative for many applications.
and that might make them a high-power alternative to batteries. At its most basic level, a battery is made of two metal electrodes (an anode and a cathode) with some sort of solution between them (electrolyte.
When the battery is charged, electrolyte ions are stored in the anode. As the battery discharges, electrolyte ions leave the anode
and move across the battery to chemically react with the cathode. The electrons necessary for this reaction travel through the external circuit,
generating an electric current. A supercapacitor is similar to a battery in that it can generate and store electric current,
but unlike a battery, the storage and release of energy does not involve chemical reactions: instead, positive and negative electrolyte ions simply tickto the surfaces of the electrodes when the supercapacitor is being charged.
When a supercapacitor is being discharged to power a device, the ions can easily opoff the surface
and move back into the electrolyte. The reason why supercapacitors charge and discharge so much faster is that the tickingand oppingprocesses happen much faster than the chemical reactions at work in a battery. o increase the area for ions to stick to,
we fill the carbon electrode with tiny holes, like a carbon sponge, said Griffin. ut it hard to know what the ions are doing inside the holes within the electrode we don know exactly what happens
when they interact with the surface. In the new study, the researchers used NMR to look inside functioning supercapacitor devices to see how they charge and store energy.
They also used a type of tiny weighing scale called an electrochemical quartz crystal microbalance (EQCM) to measure changes in mass as little as a millionth of a gram.
By taking the two sets of information and putting them together, the researchers were able to build a precise picture of
what happens inside a supercapacitor while it charges. n a battery, the two electrodes are different materials,
so different processes are said at work Griffin. n a supercapacitor, the two electrodes are made of the same porous carbon sponge,
so you think the same process would take place at both but it turns out the charge storage process in real devices is complicated more than we previously thought.
Previous theories had been made by computer simulations no one observed this in eal lifebefore. What the experiments showed is that the two electrodes behave differently.
In the negative electrode, there is the expected tickingprocess and the positive ions are attracted to the surface as the supercapacitor charges.
But in the positive electrode, an ion xchangehappens, as negative ions are attracted to the surface, while at the same time,
positive ions are repelled away from the surface. Additionally, the EQCM was used to detect tiny changes in the weight of the electrode as ions enter and leave.
This enabled the researchers to show that solvent molecules also accompany the ions into the electrode as it charges. e can now accurately count the number of ions involved in the charge storage process
and see in detail exactly how the energy is stored, said Griffin. n the future we can look at how changing the size of the holes in the electrode
and the ion properties changes the charging mechanism. This way we can tailor the properties of both components to maximise the amount of energy that is stored.
The next step, said Professor Clare P. Grey, the senior author on the paper, s to use this new approach to understand why different ions behave differently on charging, an ultimately design systems with much higher capacitances.
Funding for the project was provided by the UK Engineering and Physical sciences Research Council and the European Research Council
#Encapsulated, Nanobody-Targeted Drugs Cold Help Treat Sleeping sickness Sleeping sickness, or African trypanosomiasis, is caused by trypanosome parasites transmitted by tsetse flies
and threatens millions of people in Sub-saharan africa. The disease is considered fatal if untreated, but as it affects mostly poor people in low-income countries,
treatment options are limited. The existing drugs have serious side effects, and the parasites are developing resistance.
A study published on June 25th in PLOS Pathogens reports a new way to circumvent drug resistance
and lower the curative dose by delivering existing drugs directly into the parasite, a high-tech approach with potential applications to other infectious diseases.
Current treatment of sleeping sickness relies primarily on four drugs. Three of these drugs get into the interior of the parasite cells via the trypanosome's transport proteins that normally supply the parasite with nutrients,
and drug resistance is caused by mutations that cripple these transporters. Jose Garcia-Salcedo, from the Instituto de Investigacion Biosanitaria in Granada, Spain,
and colleagues reasoned that using an alternative way to get the drugs into parasite cells would circumvent resistance.
The researchers developed a drug carrier that consists of polymeric nanoparticles coated with specialized antibodies that target a small conserved (i e.
invariable) part of the parasite surface. Much of the trypanosome surface is highly variable, which is why the chances of developing an effective vaccine have been deemed low.)
They show that this new formulation reduces the minimal curative dose in a disease model, based on infections in mice, by 100-fold and,
most importantly, circumvents drug resistance in a cell line that is resistant as a result of mutations in the transporter that mediates drug uptake.
The authors conclude"in summary, the development of chitosan nanoparticles loaded with current trypanocidal drugs coated by a specific nanobody against trypanosomes can reduce the minimal curative dose of these drugs,
enhancing their efficacy, minimizing the toxicity and circumventing resistance mechanisms caused by mutations in surface transporters."
"The implication of this proof-of-concept study of a novel technology for reversing transporter-related drug resistance,
they say, "is limited not to a single nanobody used to demonstrate the technology, nor to a single drug, nor indeed to trypanosomiasis.""
""With a key challenge being that resistance to drugs is spreading faster than new drugs are being developed and approved,
"they suggest that"the use of encapsulated, nanobody-targeted drugs as described here has the potential to reverse resistance to many first-line treatments
#Nanotechnology Drug in Droplets for Painless Treatment of Secondary Blindness The Mexican company"Medical and Surgical Center for Retina"created a way to transport drugs,
in order to avoid risks and painful treatments in people with secondary blindness due to chronic degenerative blindness such as diabetic retinopathy and degeneration of the eye.
The innovative formula results eliminates the need to administrate the drug by intraocular injection. It is a nanotechnology product,
which works with last generation liposomes particles, concentrated in droplets, which function as a conveyor that wraps proteins
or antibody fragments and allow its passage into the eye. Once inside it releases the drugs.
With the nanotechnology product the costs are reduced by 80 to 90 percent and enables the elderly population to make use of it."
"With this technology hospitals that have no resources can apply the needed drugs, without requiring a a specialist or a particular facility for the administration.
It is necessary to be prescribed by a physician, but it can be administered at home, which lowers the cost."
"The doctor Juan carlos Altamirano Vallejo, medical director of the Medical and Surgical Center for Retina, mentions that the conditions that originate in the retina are caused mostly by chronic degenerative diseases such as diabetes (diabetic retinopathy
) or macular alteration. Patients with this conditions usually require one injection per month which comes at a very high cost
and increases if the procedure is needed for both eyes. The company, located in Jalisco (central west state of Mexico) won the Mexican National Prize for Technology
and Innovation and plans to conclude the Clinical Research regulated by the Federal Commission for Protection Against Health risks (COFEPRIS) next year.
The idea is for the medicine to be distributed in state and private health institutions. So far
the achieved results are the same as the ones obtained with intraocular injection, but without the inherent risks of this procedure, such as infection or retinal detachment.
Current talks are being held with COFEPRIS to conduct a study within several diseases and increase its use for different conditions.
In the United states, patients who have followed the treatment have had positive results. The Medical and Surgical Center for Retina provides medical care
and a specialized retina Ophthalmology Clinic provides consultation, which also has an area of`Biotechnology and Drug Research of Biomedical engineering, Diagnosis and Treatment Equipment.
Altamirano Vallejo says that receiving the award opens the doors to reach more people and prevent blindness."
"It is the most important prize delivered by the Presidency of the Republic in the area of`technology and innovation.
For us, to have an entity such as the award foundation to guide us and allows us to learn,
know skills, strengths and company administration makes us proud, specially the opportunity for a product like this to reach the market
and prevent blindness. Source: http://www. invdes. com. mx
#MEMS Innovations Enable Commercialization of Implantable Microchips for Drug-Delivery An implantable, microchip-based device may soon replace the injections
and pills now needed to treat chronic diseases: Earlier this month, MIT spinout Microchips Biotech partnered with a pharmaceutical giant to commercialize its wirelessly controlled, implantable,
microchip-based devices that store and release drugs inside the body over many years. Invented by Microchips Biotech cofounders Michael Cima, the David H. Koch Professor of Engineering,
and Robert Langer, the David H. Koch Institute Professor, the microchips consist of hundreds of pinhead-sized reservoirs,
each capped with a metal membrane, that store tiny doses of therapeutics or chemicals. An electric current delivered by the device removes the membrane,
releasing a single dose. The device can be programmed wirelessly to release individual doses for up to 16 years to treat
for example, diabetes, cancer, multiple sclerosis, and osteoporosis. Now Microchips Biotech will begin co-developing microchips with Teva Pharmaceutical, the world largest producer of generic drugs,
to treat specific diseases, with licensing potential for other products. Teva paid $35 million up front, with additional milestone payments as the device goes through clinical trials before it hits the shelves. bviously,
this is a huge validation of the technology, Cima says. major pharmaceutical company sees how this technology can further their efforts to help patients.
Apart from providing convenience, Microchips Biotech says these microchips could also improve medication-prescription adherence a surprisingly costly issue in the United states. A 2012 report published in the Annals of Internal medicine estimated that Americans who don stick to prescriptions rack up $100 billion
to $289 billion annually in unnecessary health care costs from additional hospital visits and other issues.
Failure to follow prescriptions, the study also found, causes around 125,000 deaths annually and up to 10 percent of all hospitalizations.
While its first partnership is for treating chronic diseases, Microchips Biotech will continue work on its flagship product, a birth-control microchip, backed by the Bill and Melinda Gates Foundation,
that releases contraceptives and can be turned on and off wirelessly. Cima, who now serves on the Microchips Biotech board of directors with Langer,
sees this hormone-releasing microchip as one of the first implantable rtificial organsbecause it acts as a gland. lot of the therapies are trying to chemically trick the endocrine systems Cima says. e are doing that with this artificial organ we created.
Wild ideas Inspiration for the microchips came in the late 1990s, when Langer watched a documentary on mass-producing microchips. thought to myself,
ouldn this be a great way to make a drug-delivery system??Langer says. He brought this idea to Cima,
a chip-making expert who was taken aback by its novelty. ut being out-of-this-world is not something that needs to stop anybody at MIT,
Cima adds. n fact, that should be the criterion. So in 1999, Langer, Cima, and then-graduate student John Santini Phd 9 co-founded Microchips,
and invented a prototype for their microchip that was described in a paper published that year in Nature.
This entrepreneurial collaboration was the first of many for Cima and Langer over the next decade.
This dime-sized prototype contained only 34 reservoirs, each controlled by an individual wire connected to an external power source.
At the time, they considered a broad range of practical, and somewhat fantastical, applications beyond drug delivery, including disease diagnostics
and jewelry that could emit scents. e were trying to find the killer application. We thought,
have a hammer, what the right nail to hit??Cima says. For years, the technology underwent rigorous research and development at Microchips Biotech.
But in 2011, Langer and Cima, and researchers from Microchips, conducted the microchipsfirst human trials to treat osteoporosis this time with wireless capabilities.
In that study, published in a 2012 issue of Science Translational Medicine, microchips were implanted into seven elderly women,
delivering teriparatide to strengthen bones. Results indicated that the chips delivered doses comparable to injections and did so more consistently with no adverse side effects.
After that, the Gates Foundation took interest. t wasn just a pie-in-the-sky idea anymore wee really treating patients
Cima says. hat really captures people imaginations. That study, combined with ongoing efforts in contraceptive-delivery microchips,
led Cima to believe the microchips could someday, essentially, be considered the first artificial glands that could regulate potent hormones inside the body.
This may sound like a wild idea but Cima doesn think so. Consider the thousands of people living today with pacemakers,
he says. acemakers are delivering an electrical signal, fixing the pace of a heart, or detecting if the heart is not beating correctly,
and trying to stimulate it, Cima says. The chip ends an endocrine or chemical signal
instead of an electrical signal. MEMS innovations Microchips Biotech made several innovations in the microelectromechanical systems (MEMS) manufacturing process to ensure the microchips could be commercialized.
A major innovation was enabling final assembly of the microchips at room temperature with hermetic seals. Any intense heat during final assembly, with hermetic sealing, could destroy the drugs already loaded into the reservoirs
which meant common methods of welding and soldering were off-limits. To do so, Microchips Biotech modified a cold-welding ongue and grooveprocess.
This meant depositing a soft, gold alloy in patterns on the top of the chip to create tongues, and grooves on the base.
By pressing the top and base pieces together, the tongues fit into the grooves, and plastically deforms to weld the metal together. ach one of these reservoirs,
until you open it, must be sealed completely from any contaminant in the environment, Cima says. here was no precedent for that.
The company has also found ways to integrate electronics into the microchips to shrink down the device.
Moving forward, Langer adds, the company could refine the microchips to be even smaller, yet carry the same volume of drugs. his means making the drugs take up more volume than the electrical and other components,
he says. hat the next major challenge. k
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