Pills of the future: Nanoparticles; Researchers design drug-carrying nanoparticles that can be taken orally

Now, researchers from MIT and Brigham and Women's Hospital (BWH) have developed a new type of nanoparticle that can be delivered orally and absorbed through the digestive tract, allowing patients to simply take a pill instead of receiving injections.

In a paper appearing in the Nov. 27 online edition of Science Translational Medicine, the researchers used the particles to demonstrate oral delivery of insulin in mice, but they say the particles could be used to carry any kind of drug that can be encapsulated in a nanoparticle. The new nanoparticles are coated with antibodies that act as a key to unlock receptors found on the surfaces of cells that line the intestine, allowing the nanoparticles to break through the intestinal walls and enter the bloodstream.

This type of drug delivery could be especially useful in developing new treatments for conditions such as high cholesterol or arthritis. Patients with those diseases would be much more likely to take pills regularly than to make frequent visits to a doctor's office to receive nanoparticle injections, say the researchers.

"If you were a patient and you had a choice, there's just no question: Patients would always prefer drugs they can take orally," says Robert Langer, the David H. Koch Institute Professor at MIT, a member of MIT's Koch Institute for Integrative Cancer Research, and an author of the Science Translational Medicine paper.

Lead authors of the paper are former MIT grad student Eric Pridgen and former BWH postdoc Frank Alexis, and the senior author is Omid Farokhzad, director of the Laboratory of Nanomedicine and Biomaterials at BWH. Other authors are Timothy Kuo, a gastroenterologist at BWH; Etgar Levy-Nissenbaum, a former BWH postdoc; Rohit Karnik, an MIT associate professor of mechanical engineering; and Richard Blumberg, co-director of BWH's Biomedical Research Institute.

Ref : http://stm.sciencemag.org/content/5/213/213ra167

Pills of the future: Nanoparticles; Researchers design drug-carrying nanoparticles that can be taken orally

Inexpensive 'nano-camera' can operate at the speed of light

Inexpensive 'nano-camera' can operate at the speed of light

Copper promises cheaper, sturdier fuel cells

The copper nanowire films consist of networks of microscopic metal rods, the properties and applications of which Wiley's lab has studied for years. The nanowires provide a high surface area for catalyzing chemistry, and Wiley's team experimented with coating them in either cobalt or nickel -- metals that serve as the actual chemical catalyst. Even with a coat of cobalt or nickel, the nanowire films allow nearly seven times more sunlight to pass through than ITO. The films are also flexible, leading Wiley to imagine the completed fuel cells one day being attached to backpacks or cars.

In the meantime, engineering and chemistry challenges remain. The nanowire films carry out only one half of the water-splitting equation, a process called water oxidation. The other half of the reaction involves using the electrons obtained from water oxidation to reduce water to hydrogen. Wiley's team expects to publish their work on this process in the coming year.

"A lot of groups are working on putting together complete devices to generate fuels from sunlight," he said, but "the efficiencies and costs of these systems have to be improved for them to get to commercial [production]."

Wiley noted that solar energy production is just one application of the copper nanowire films they study. The nanowires also show promise for use in flexible touch screens, organic LED (or OLED) lights and smart glass.

Copper promises cheaper, sturdier fuel cells

Nanotechnology-based technique: A painless method for maintaining healthy blood sugar levels

A new nanotechnology-based technique for regulating blood sugar in diabetics may give patients the ability to release insulin painlessly using a small ultrasound device, allowing them to go days between injections - rather than using needles to give themselves multiple insulin injections each day. The technique was developed by researchers at North Carolina State University and the University of North Carolina at Chapel Hill.

"This is hopefully a big step toward giving diabetics a more painless method of maintaining healthy blood sugar levels," says Dr. Zhen Gu, senior author of a paper on the research and an assistant professor in the joint biomedical engineering program at NC State and UNC-Chapel Hill.

The technique involves injecting biocompatible and biodegradable nanoparticles into a patient's skin. The nanoparticles are made out of poly(lactic-co-glycolic) acid (PLGA) and are filled with insulin.

Each of the PLGA nanoparticles is given either a positively charged coating made of chitosan (a biocompatible material normally found in shrimp shells), or a negatively charged coating made of alginate (a biocompatible material normally found in seaweed). When the solution of coated nanoparticles is mixed together, the positively and negatively charged coatings are attracted to each other by electrostatic force to form a "nano-network." Once injected into the subcutaneous layer of the skin, that nano-network holds the nanoparticles together and prevents them from dispersing throughout the body.

Nanotechnology-based technique: A painless method for maintaining healthy blood sugar levels

Nanotech drug smugglers

Sergey Shityakov and Carola Förster of the University of Würzburg, Germany, explain that the protein, P-glycoprotein, acts as a gatekeeper, flushing out potentially harmful chemicals that enter the body as well as the naturally-occurring products of metabolism. The protein thus plays a vital role in the health of the cell. Unfortunately, it is a strong modulator of chemical traffic across the cell membrane that it can also prevent therapeutic agents from working properly, flushing them out as if they were simply harmful compounds. This process underpins the emergence of multidrug resistance in several diseases, including various forms of cancer.

Shityakov and Förster have revealed recently that if there were a way to mask the presence of the therapeutic agent, later the gatekeeper would not see them as "unwanted molecular entities" to be eradicated, and therefore, these drugs might be able to carry out their job unhindered and so overcome drug resistance. However, some of the chemical substances have turned to the realm of nanotechnology, and in particular, tiny capsules of carbon atoms known as fullerenes and the related molecules, the carbon nanotubes. The latter synthetic materials are not recognized by P-glycoprotein and so can penetrate lipid membranes moving freely in and out of cells.

The team has investigated whether it might be possible to carry drug molecules inside these nanocapsules so that they are unimpeded by interactions with P-glycoprotein or other receptors. They used high-power computational techniques to demonstrate that carbon nanotubes are not able to "dock" with the gatekeeper protein. Moreover, their analysis of the binding energy needed to push a nanotube into P-glycoprotein shows that the process is unfavourable and so rather than "docking" with this gatekeeper protein these peculiar materials are repelled by it to maintain the interior of the cell and so have the potential to act as a molecular drug smuggler.

Ref : http://www.inderscience.com/offer.php?id=56801

Nanotech drug smugglers

Graphene nanoribbons with nanopores created for fast DNA sequencing

The instructions for building all of the body's proteins are contained in a person's DNA, a string of chemicals that, if unwound and strung end to end, would form a sentence 3 billion letters long. Each person's sentence is unique, so learning how to read gene sequences as quickly and inexpensively as possible could pave the way to countless personalized medical applications. 

heir DNA sensor is based on graphene, an atomically thin lattice of carbon. Earlier versions of the technique only made use of graphene's unbeatable thinness, but the Penn team's research shows how the Nobel Prize-winning material's unique electrical properties may be employed to make faster and more sensitive sequencing devices.

Critically, the team's latest study shows how to drill these nanopores without ruining graphene's electrical sensitivity, a risk posed by simply looking at the material through an electron microscope.

The team includes Marija Drndić, professor of physics in the School of Arts and Sciences, and members in her laboratory, including graduate student Matthew Puster and postdoctoral researchers Julio Rodríguez-Manzo and Adrian Balan.

Their research was published in the journal ACS Nano.

Drndić's group has previously demonstrated a series of advancements towards reading genes by passing them through a tiny hole, or nanopore. Their 2010 study involved drilling a hole in a sheet of graphene, then putting it in an ionic bath along with the strands of DNA to be detected. Because each of the four bases, the letters in DNA's alphabet, have a different size, a different number of ions would be expected to squeeze through along with each base as the strand passes through the pore. Researchers could then interpret the sequence of the DNA's bases by measuring the electrical signal of the ions. However, those current signals are weak, limiting the speed at which DNA could be sequenced.

Many research groups are now exploring multiple ways to improve the sensitivity and speed of the technique, including new materials and new ways of fashioning nanopores in them. Drndić's group has experimented with different membranes, as well as adding improved electronics to measure at faster speeds, but its latest study represents an entirely new way of generating an electrical signal unique to each base.

http://pubs.acs.org/doi/abs/10.1021/nn405112m

Graphene nanoribbons with nanopores created for fast DNA sequencing

Nanotechnology researchers prove two-step method for potential pancreatic cancer treatment

The dual-wave nanotherapy method employed by Drs. Nel and Meng in their research uses two different kinds of microscopic particles (nanoparticles) intravenously injected in a rapid sequence into the vein of the tumor-bearing mouse. The first wave of nanoparticles carries a substance that removes the pericytes' vascular gates to access the pancreatic cancer cells and the second wave carries the chemotherapy drug that kills the cancer cells.

Drs. Nel and Meng and their colleagues Dr. Jeffrey Zink, UCLA professor of chemistry and biochemistry and Dr. Jeffrey Brinker, University of New Mexico professor of chemical and nuclear engineering, sought to contain chemotherapy in nanoparticles that could more directly target pancreatic cancer cells, but they needed to find a way for those nanoparticles to get through the sites of vascular obstruction caused by the pericytes, which restricts access to the cancer cells. Through experimentation they discovered they could interfere with a cellular signaling pathway (the communication mechanism between cells) that governs the pericyte attraction to the tumor blood vessels. By making nanoparticles that effectively bind a high load of the signaling pathway inhibitor, they developed a first wave of nanoparticles that separates the pericytes from the endothelial cells (on the blood vessel). This opens the vascular gate for the next wave of nanoparticles, which carry the chemotherapeutic agent to the cancer cells inside the tumor.

To test this two-wave nanotherapy, the researchers used immuno-compromised mice that were used to grow human pancreatic tumors (called xenografts) under the mouse skin. With the two-wave method, the xenograft tumors had a significantly higher rate of shrinkage compared to those exposed to chemotherapy given the standard way as a free drug or carried in nanoparticles without first wave treatment.

"This two-wave nanotherapy is an existing example of how we seek to improve the delivery of chemotherapy drugs to their intended targets using nanotechnology to provide an engineered approach," said Nel, chief of the division of nanomedicine. "It shows how the physical and chemical principles of nanotechnology can be integrated with the biological sciences to help cancer patients by increasing the effectiveness of chemotherapy while also reducing side effects and toxicity. This two-wave treatment approach can also address biological impediments in nanotherapies for other types of cancer."

Ref : http://pubs.acs.org/doi/abs/10.1021/nn404083m

Nanotechnology researchers prove two-step method for potential pancreatic cancer treatment

Better batteries through biology? Modified viruses boost battery performance

MIT researchers have found a way to boost lithium-air battery performance, with the help of modified viruses. 

MIT researchers have found that adding genetically modified viruses to the production of nanowires -- wires that are about the width of a red blood cell, and which can serve as one of a battery's electrodes -- could help solve some of these problems.

The new work is described in a paper published in the journal Nature Communications, co-authored by graduate student Dahyun Oh, professors Angela Belcher and Yang Shao-Horn, and three others. The key to their work was to increase the surface area of the wire, thus increasing the area where electrochemical activity takes place during charging or discharging of the battery.

The researchers produced an array of nanowires, each about 80 nanometers across, using a genetically modified virus called M13, which can capture molecules of metals from water and bind them into structural shapes. In this case, wires of manganese oxide -- a "favorite material" for a lithium-air battery's cathode, Belcher says -- were actually made by the viruses. But unlike wires "grown" through conventional chemical methods, these virus-built nanowires have a rough, spiky surface, which dramatically increases their surface area.

Belcher, the W.M. Keck Professor of Energy and an affiliate of MIT's Koch Institute for Integrative Cancer Research, explains that this process of biosynthesis is "really similar to how an abalone grows its shell" -- in that case, by collecting calcium from seawater and depositing it into a solid, linked structure.

The increase in surface area produced by this method can provide "a big advantage," Belcher says, in lithium-air batteries' rate of charging and discharging. But the process also has other potential advantages, she says: Unlike conventional fabrication methods, which involve energy-intensive high temperatures and hazardous chemicals, this process can be carried out at room temperature using a water-based process.

Also, rather than isolated wires, the viruses naturally produce a three-dimensional structure of cross-linked wires, which provides greater stability for an electrode.

Ref : http://www.nature.com/ncomms/2013/131113/ncomms3756/full/ncomms3756.html

Better batteries through biology? Modified viruses boost battery performance

Breathalyzer technology detects acetone levels to monitor blood glucose in diabetics

A novel hand-held, noninvasive monitoring device that uses multilayer nanotechnology to detect acetone has been shown to correlate with blood-glucose levels in the breath of diabetics. This research is being presented at the 2013 American Association of Pharmaceutical Scientists (AAPS)Annual Meeting and Exposition, the world’s largest pharmaceutical sciences meeting, in San Antonio, Nov. 10–14. Read more 

Breathalyzer technology detects acetone levels to monitor blood glucose in diabetics

All aboard the nanotrain network: Tiny self-assembling transport networks, powered by nano-scale motors and controlled by DNA

Tiny self-assembling transport networks, powered by nano-scale motors and controlled by DNA, have been developed by scientists at Oxford University and Warwick University.

The system can construct its own network of tracks spanning tens of micrometres in length, transport cargo across the network and even dismantle the tracks.

The work is published in Nature Nanotechnology and was supported by the Engineering and Physical Sciences Research Council and the Biotechnology and Biological Sciences Research Council.

Researchers were inspired by the melanophore, used by fish cells to control their colour. Tracks in the network all come from a central point, like the spokes of a bicycle wheel. Motor proteins transport pigment around the network, either concentrating it in the centre or spreading it throughout the network. Concentrating pigment in the centre makes the cells lighter, as the surrounding space is left empty and transparent.

The system developed by the Oxford University team is very similar, and is built from DNA and a motor protein called kinesin. Powered by ATP fuel, kinesins move along the micro-tracks carrying control modules made from short strands of DNA. 'Assembler' nanobots are made with two kinesin proteins, allowing them to move tracks around to assemble the network, whereas the 'shuttles' only need one kinesin protein to travel along the tracks.

'DNA is an excellent building block for constructing synthetic molecular systems, as we can program it to do whatever we need,' said Adam Wollman, who conducted the research at Oxford University's Department of Physics. 'We design the chemical structures of the DNA strands to control how they interact with each other. The shuttles can be used to either carry cargo or deliver signals to tell other shuttles what to do.

'We first use assemblers to arrange the track into 'spokes', triggered by the introduction of ATP. We then send in shuttles with fluorescent green cargo which spread out across the track, covering it evenly. When we add more ATP, the shuttles all cluster in the centre of the track where the spokes meet. Next, we send signal shuttles along the tracks to tell the cargo-carrying shuttles to release the fluorescent cargo into the environment, where it disperses. We can also send shuttles programmed with 'dismantle' signals to the central hub, telling the tracks to break up.'

This demonstration used fluorescent green dyes as cargo, but the same methods could be applied to other compounds. As well as colour changes, spoke-like track systems could be used to speed up chemical reactions by bringing the necessary compounds together at the central hub. More broadly, using DNA to control motor proteins could enable the development of more sophisticated self-assembling systems for a wide variety of applications.

Ref : http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2013.230.html

All aboard the nanotrain network: Tiny self-assembling transport networks, powered by nano-scale motors and controlled by DNA

Nanotechnology Now - "Laser diodes versus LEDs"

Solid-state lighting (SSL) has recently become competitive with conventional light sources and is now the most efficient source of high color quality white light ever created. At the heart of SSL is the light-emitting diode (LED). The current standard architecture for SSL is the phosphor-converted light-emitting diode (PCLED) in which high-brightness InGaN blue LEDs are combined with one or more wavelength-downconverting phosphors to produce composite white light of virtually any color temperature and color rendering quality. Despite this success, blue LEDs still have significant performance limitations, especially a nonthermal drop in efficiency with increasing input power density called "efficiency droop" which limits operation to relatively low input power densities, contrary to the desire to produce more photons per unit area of the LED chip and to thereby make SSL more affordable.

An alternative could be a blue laser diode (LD). LDs can in principle have high efficiencies at much higher input power densities than LEDs. Above the lasing threshold, parasitic nonradiative recombination processes, including those likely responsible for efficiency droop in LEDs, are clamped at their rates at lasing threshold. Indeed, at high input power densities state-of-the-art, high-power, blue, edge-emitting LDs already have reasonably high (30%) power-conversion efficiencies, with the promise someday of even higher efficiencies. A team from Sandia National Laboratories, Albuquerque (NM, USA) and Corning Incorporated, Corning (NY, USA) compared LEDs and LDs and discuss their economics for practical SSL

The scientists refer to the tremendous progress made in both device types, with current state-of-the-art power-conversion efficiencies (PCEs) of 70% for LEDs and 30% for LDs. The input power densities, at which these PCEs peak, are vastly different at about 10 W/cm2 for LEDs and 25 kW/cm2 for LDs. As the areal chip cost necessary for economical lighting scales as input power density, areal chip cost can be much higher for LDs than for LEDs. The authors conclude that it appears to be much more challenging to achieve areal chip costs low enough for LEDs than for LDs to be operated at the input

Power densities at which their PCEs peak.

Yet, as heat-sink-limited single-chip white-light output scales inversely as input power density, heat-sink-limited single-chip white-light output can be much higher for LEDs than for LDs. A white-light output high enough for practical illumination applications should be more challenging to achieve for LDs than for LEDs.

The researchers conclude, that for both, LEDs and LDs, the solution will be to shift the input power density at which their PCEs peak. Whereas LEDs need to shift to higher input power density to offset higher areal chip cost, LDs need to shift to lower input power density to enable higher white-light output. In other words, both LEDs and LDs will be made more practical and economical if they can move into and fill the "valley of droop". (Text contributed by K. Maedefessel-Herrmann)

Nanotechnology Now - Press Release: "Laser diodes versus LEDs"

"Nanogrid, activated by sunlight, breaks down pollutants in water, leaving biodegradable compounds: Innovation Corps project explores how to bring technology to the field"

Pelagia-Irene (Perena) Gouma, a professor in the Department of Materials Science and  Engineering at the State University of New York (SUNY) Stony Brook, created a novel "nanogrid," a large net consisting of metal grids made of a copper tungsten oxide, that, when activated by sunlight, can break down oil from a spill, leaving only biodegradable compounds behind.

"We have made a new catalyst that can break down hydrocarbons in water, and it does not contaminate the water," says Gouma, who also directs SUNY's Center for Nanomaterials and Sensor Development. "It utilizes the whole solar spectrum and can work in water for a long time, which no existing photocatalyst can do now. Ours is a unique technology. When you shine light on these grids, they begin to work and can be used over and over again.

"Something like this would work fine for any oil spill," Gouma adds. "Any ship can carry them, so if they have even a small amount of spill, they can take care of it."

Initially, the grids, which resemble non-woven mats of miniaturized ceramic fishing nets, probably will be used for oil spills, although they potentially could prove valuable in other applications, such as cleaning contaminated water produced by "fracking," the process of hydraulic fracturing to extract natural gas from shale, and as well as from other industrial processes.

"Fracking is a reality," she says. "It is happening. If the science and engineering we produce in the lab can help alleviate environmental problems, we will be happy about that."

Because they work well both in water and air, they also could be a chemical-free, possibly even water-free, method of cleaning clothes in the future. "The dry cleaning process that we now use involves a lot of contaminants that have to be remediated and treated, such as benzene," she says. "This could be a dry cleaning substitute that would be more environmentally friendly than current dry cleaning approaches."

Moreover, "imagine you lay this over your clothes, and expose them to light. You won't need a washing machine, or chemicals, or even water," she adds.

The photocatalytic nanogrids™ invented in her lab are made by a unique self-assembly process that occurs "during the nanomanufacturing on non-woven nanofibrous mats deposited on metal meshes," according to Gouma. "Upon heating, metal clusters diffuse inside polymeric nanofibers, then turn into single crystal nanowires, then oxidize to form metal oxide--ceramic--nanoparticles that are interconnected, like links in a chain," she says.

These form an unusual and "robust third architecture that allows for the highest surface area, providing maximum exposure to the contaminant to be remediated, while the nanoscale particle sizes enable fast catalytic action," she adds. "The result is a self-supported water remediation targeted photocatalytic technology that has no precedent."

In the fall of 2011, Gouma was the first scientist to receive a $50,000 NSF Innovation Corps (I-Corps) award, which supports a set of activities and programs that prepare scientists and engineers to extend their focus beyond the laboratory into the commercial world.

Such results may be translated through I-Corps into technologies with near-term benefits for the economy and society. It is a public-private partnership program that teaches grantees to identify valuable product opportunities that can emerge from academic research, and offers entrepreneurship training to faculty and student participants.

Nanotechnology Now - Press Release: "Nanogrid, activated by sunlight, breaks down pollutants in water, leaving biodegradable compounds: Innovation Corps project explores how to bring technology to the field"

Carbon nanotube jungles created to better detect molecules

Researchers from Lawrence Livermore National Laboratory (LLNL) and the Swiss Federal Institute of Technology (ETH) in Zurich have developed a new method of using nanotubes to detect molecules at extremely low concentrations enabling trace detection of biological threats, explosives and drugs.

The joint research team, led by LLNL Engineer Tiziana Bond and ETH Scientist Hyung Gyu Park, are using spaghetti-like, gold-hafnium-coated carbon nanotubes (CNT) to amplify the detection capabilities in surface-enhanced Raman spectroscopy (SERS).

SERS is a surface-sensitive technique that enhances the inelastic scattering of photons by molecules adsorbed on rough metal surfaces or by nanostructures.

Bond and her collaborators are using metal-coated nanotubes bunched together like a jungle canopy to amplify the signals of both the incident and Raman scattered light by exciting local electron plasmons.

Their real breakthrough, however, is discovering the use of an intermediate dielectric coating (hafnium) to block the quenching of the free electrons in the metal by the CNTs, allowing the nanotubes to function uninhibited. By preserving the electrons and enhancing the light through the use of nanotube jungles, the team is able to significantly increase the SERS' detection sensitivities in CNTs structures.

The hafnium coating enables the bunching of gold nanotubes that creates a thick canopy full of sensitive spots for detection. The nanotubes enable incident light to be trapped and focused at the numerous contact points and crevices, allowing the Raman-scattered light to pass through. This enables portable Raman devices to detect and identify specific airborne substances randomly.

"This is a very important discovery in our efforts to improve the use of SERS devices," Bond said. "We gained this valuable knowledge through multidisciplinary basic research and approaching the problem with a rational design."

Bond and Park hope their engineered material will eventually be used in portable devices to conduct on-site analysis of chemical impurities such as environmental pollutants or pharmaceutical residues in water. Other applications include the real-time point-of-care monitoring of physiological levels for the biomedical industry and fast screening of drugs and toxins for law enforcement.

"We are in the process of filing a patent for our new discovery," Bond said.

Ref : http://onlinelibrary.wiley.com/doi/10.1002/adma.201300571/abstract

Carbon nanotube jungles created to better detect molecules

Nanotechnology Now - Press Release: "Thermotherapy of Cancer by Synthesizing Magnetite Magnetic Nanoparticles"

The simultaneous use of thermotherapy and chemotherapy significantly increases the rate of the treatment of cancerous tumor.  In this method, magnetite magnetic nanoparticles were firstly produced through co precipitation of Fe (II) and Fe (III) salts in the presence of  ammonia. Then their surfaces were modified by  cationic albumin. Finally, the produced nanoparticles were used in thermotherapy. When   magnetite nanoparticles are imposed to alternating current magnetic field, nanoparticles turn into powerful thermal sources that are able to degrade tumor cells. 

The new nanoparticles are able to reach the temperature of 60°C in the presence of alternating current magnetic field with a frequency of 215 kHz. It shows the noticeable ability of the  nanoparticles to produce heat to degrade cancerous cells.

The nanoparticles can be used simultaneously in the diagnosis and treatment of cancer, because the nanoparticles can be used as the contrast maker in cancer diagnosis by using MRI, as the carrier of chemotherapy drug in targeted drug delivery, and as the source to produce heat in thermotherapy of cancer.

Nanotechnology Now - Press Release: "Thermotherapy of Cancer by Synthesizing Magnetite Magnetic Nanoparticles"

Nanotechnology Now - Press Release: "New discovery could dramatically reduce leishmaniasis treatment doses and side effects: An 83 percent improvement in efficacy in the drug most commonly used to treat leishmaniasis"

The Amphotericin B (AmB, see structure) is the main active ingredient in the most effective drug used to treat leishmaniasis, a disease which in the Western world mainly affects dogs, but in developing countries affects over 12 million people, with more than 70,000 deaths per year. The cost of treating humans with AmB surpasses $5,000 per patient, the treatment is extensive (2-hour sessions every day during 21 days), and the side effects are frequent and many times patients must be hospitalised.

New discovery could dramatically reduce leishmaniasis treatment doses and side effects: An 83 percent improvement in efficacy in the drug most commonly used to treat leishmaniasis

Researchers from the University of Miami, Florida and the Universitat Autònoma de Barcelona have developed a method which allows to drastically reduce the drug dose, since it improves its efficacy 83%, multiplies by 10 the capacity of the drug to attack cell infected by the parasite which provokes the disease, and significantly reduces the toxicity of the parasite. The method has been successfully tested on mice models of leishmaniasis.

The complex compound acts through the action of the PDD nanoparticle, a substance measuring some 10 nanometres in diameter which is fit into the active principle, Amphotericin B, and guides it selectively to the cells harbouring the parasite. Scientists observed how, while the usual complete dose of the drug requires over 12 days to reduce the skin lesions caused by the disease, one dose of the complex compound with only 17% of the complete dose of the drug improves skin lesions in two or three days. Moreover, the complex compound acts as a therapeutic vaccine which activates the immune system against the reservoir cells hosting the parasite.

The PDD substance has been used in previous trials with people with the aim of improving the response of their immune system to other diseases. Now there is a need for clinical trials with humans in order to verify its safety as an adjuvant in the treatment of leishmaniasis. If its safety in humans is confirmed, it will also reduce the cost of the treatment drastically, and this is a key element in reducing mortality rates in developing countries.

Ref : http://jid.oxfordjournals.org/content/208/11/1914.abstract?sid=710e7d94-b96d-4ac0-a089-ec2c06176b4b

Nanotechnology Now - Press Release: "New discovery could dramatically reduce leishmaniasis treatment doses and side effects: An 83 percent improvement in efficacy in the drug most commonly used to treat leishmaniasis"

Photoactivated rose bengal functionalized chitosan nanoparticles produce antibacterial/biofilm activity and stabilize dentin-collagen

Treatment of infected teeth presents two major challenges: persistence of the bacterial-biofilm within root canals after treatment and compromised structural integrity of the dentin hard-tissue. In this study bioactive polymeric chitosan   nanoparticles functionalized with rose-bengal, CSRBnp was developed to produce antibiofilm effects as well as stabilize structural-integrity by photocrosslinking dentin-collagen. CSRBnp was less toxic to fibroblasts and had   significant antibacterial activity even in the presence of bovine serum albumin. CSRBnp exerted antibacterial mechanism by adhering to bacterial cell surface, permeabilizing the membrane and lysing the cells subsequent to photodynamic treatment. Photoactivated CSRBnp resulted in reduced viability of Enterococcus faecalis biofilms and disruption of biofilm structure. Incorporation of CSRBnp and photocrosslinking significantly improved resistance to degradation and mechanical strength of dentin-collagen (p < 0.05). The functionalized chitosan nanoparticles provided a single-step treatment of infected root dentin by combining the properties of chitosan and that of photosensitizer to eliminate bacterial-biofilms and stabilize dentin-matrix.

Photoactivated rose bengal functionalized chitosan nanoparticles produce antibacterial/biofilm activity and stabilize dentin-collagen

Nanotechnology – The major frontier area of science and technology………

We can define nanoscience as the study of phenomena and manipulation of materials at atomic, molecular and macromolecular scales, where properties differ significantly from those at a larger scale; and nanotechnologies as the design, characterization, production and application of structures, devices and systems by controlling shape and size at the nanometer scale. Definition, the design, characterization, production, and application of structures, devices, and systems by controlled manipulation of size and shape at the nanometer scale (atomic, molecular, and macromolecular scale) that produces structures, devices, and systems with at least one novel/superior characteristic or property.

History :…….

•      Carbon Nanotubes (first observed by  Sumio Iijima in 1991.).
•    Inorganic nanotubes and inorganic fullerene-like materials based on layered compounds such as molybdenum disulphide were discovered shortly after CNTs.
•     Nanowires are ultrafine wires or linear arrays of dots, formed by self-assembly (e.g., semiconductor nanowires made of silicon).
•    Biopolymers -  variability and site recognition of biopolymers, such as DNA molecules. 
•     Nanotechnologists claim that the combination of one-dimensional nanostructures consisting of biopolymers and inorganic compounds opens up a number of scientific and technological opportunities.

Reasons for the difference in the properties : (at the nanoscale) First, nanomaterials have a relatively larger surface area when compared to the same mass of material produced in a larger form. This can make materials more chemically reactive (in some cases materials that are inert in their larger form are reactive when produced in their nanoscale form), and affect their strength or electrical properties.  Second, quantum effects can begin to dominate the behavior of matter at the nanoscale - particularly at the lower end - affecting the optical, electrical and magnetic behavior of materials. Materials can be produced that are nanoscale in one dimension (for example, very thin surface coatings), in two dimensions (for example, nanowires and nanotubes) or in all three dimensions (for example, nanoparticles).

Current applications of nanoscale materials include very thin coatings used, for example, in electronics and active surfaces (for example, self-cleaning windows). In most applications the nanoscale components will be fixed or embedded but in some, such as those used in cosmetics and in some pilot environmental remediation applications, free nanoparticles are used. The ability to machine materials to very high precision and accuracy (better than 100nm) is leading to considerable benefits in a wide range of industrial sectors, for example in the production of components for the information and communication technology, automotive and aerospace industries.

Current Applications (success achieved to some extent):

• Sunscreens and Cosmetics (nano sized titanium dioxide and zinc oxide-which absorb and reflect ultraviolet (UV) rays and yet are transparent to visible light).
• Composites (carbon black used as a filler to reinforce car tyres).
• Clays  (nano-sized flakes of clay- use in car bumpers).
• Coatings and Surfaces (e.g., self-cleaning window : coated with  highly activated titanium dioxide, engineered to be highly hydrophobic (water repellent) and antibacterial, and coatings based on nanoparticulate oxides that catalytically destroy chemical agents.)
• Tougher and Harder Cutting Tools [tungsten carbide, tantalum carbide and titanium carbide, are more wear and erosion-resistant, and last longer than their conventional (large-grained) counterparts].

Future of Nanotechnology: Although present ones represent incremental developments, surfaces with enhanced properties should find applications throughout the chemicals and energy sectors. The benefits could surpass the obvious economic and resource savings achieved by higher activity and greater selectivity in reactors and separation processes, to enabling small-scale distributed processing (making chemicals as close as possible to the point of use). There is already a move in the chemical industry towards this. Another use could be the small-scale, on-site production of high value chemicals such as pharmaceuticals. Two dimensional nanomaterials such as tubes and wires have generated considerable interest among the scientific community in recent years. In particular, their novel electrical and mechanical properties are the subject of intense research.

•      Paints.
•   Remediation  (potential of nanoparticles to react with pollutants in soil and groundwater and transform them into harmless compounds).
•    Fuel Cells (potential use of nano-engineered membranes to intensify catalytic processes could enable higher-efficiency, small-scale fuel cells).
•      Displays (next generation of light-emitting phosphors- nanocrystalline zinc selenide, zinc sulphide, cadmium sulphide and lead telluride synthesized by sol–gel techniques).
•      Batteries (Nickel–metal hydride batteries made of nanocrystalline nickel and metal hydrides are envisioned to require less frequent recharging and to last longer because of their large grain boundary /surface  area).
•     Fuel Additives  (addition of nanoparticulate ceria (cerium oxide) to diesel fuel to improve fuel economy by reducing the degradation of fuel consumption over time).
•     Catalysts (uniformity in the size and chemical structure of the catalyst, which in turn leads to greater catalytic activity and the production of fewer byproducts).
•    Research is also being undertaken in many fields such as a) Carbon Nanotube Composites, b) Lubricants,  c) Magnetic Materials, d) Medical Implants,  e) Machinable Ceramics, f) Water Purification, g) Military Battle Suits, h). Drug delivery, i)Vaccines,  j)Biomedical Applications-biosensors, k)stain resistant textiles, l) CNT reinforced tennis rackets and baseball bats, m) Low-cost printing technique for a new generation of complex, flexible sensors.

To conclude I would say, nanotechnology is the major frontier area of science and technology and   if developed into an advanced technology, will be indistinguishable from the magic. Where does the magic come from? magic's in the learning (quoting Dar Williams).. so let us learn, invent and explore “nanotechnology”……..