Articles from December 2013

3D Printed Liver

Liver cells, in particular the parenchymal hepatocytes, are widely used in the laboratory to assess the potential toxicity or efficacy of drugs. Hepatocytes inside the body have a nearly unlimited capacity for replication. When as much as two-thirds of a whole healthy liver is surgically removed, the hepatocytes within the liver remnant undergo rapid and extensive proliferation to restore liver mass completel.

In the other hand, 3D bioprinted human tissues can be constructed with precision from tiny building blocks made of living human cells, using a process that translates tissue-specific geometries and cellular components into 3D designs that can be executed by a device designed by the Californian company Organovo. Once built, the bioprinted tissues share many key features with native tissue, including tissue-like cellular density, presence of multiple cell types, and the development of key architectural and functional features associated with the target native tissue.
bioprinted human liver tissue

This image is a cross-section of bioprinted human liver tissue demonstrating compartmentalization between the hepatocytes (shown as blue nuclei), endothelial cells (red), and hepatic stellate cells (green)
The overall goal is to develop living, multi-cellular human tissues that can be maintained in the laboratory environment for extended periods of time and sampled serially for both functional and histological changes in response to injury, pathogens, or treatments.

Renewable Hydrogen From Water And Sunlight

Researchers at the Institute of Energy Technology (INTE) of the Universitat Politècnica de Catalunya· BarcelonaTech (UPC), the University of Auckland (New Zealand), and King Abdullah University of Science and Technology (Saudi Arabia) have developed a system to produce hydrogen from water and sunlight in a way that is clean, renewable and more cost-effective than other methods. The scientists behind the project have fused the optical properties of three-dimensional photonic crystals (inverse opals of titanium dioxide, TiO2) and 2-3 nm gold nanoparticles to develop a highly active catalyst powder. The research paper has been published in Scientific Reports, the open-access journal of Nature.

This new photocatalyst produces more hydrogen than others developed so far by harnessing the properties of both photonic crystals and nanoparticles of a metal. According to Jordi Llorca, a researcher at the UPC’s Institute of Energy Technology, the process involves “tuning” the two materials to amplify the effect. “You have to choose the right photonic crystal and the right nanoparticles“, he adds.

The new catalyst has great potential for application in industrial processes. According to researcher Jordi Llorca, making the move from the laboratory to an industrial plant would mean designing a reactor to operate outdoors in the sun, and using a solar collector to capture more sunlight.

A conventional plant for the production of hydrogen from natural gas generates about 300 tons of hydrogen a day. With the new catalyst developed at the UPC, researchers have managed to produce 0.025 litres of hydrogen in one hour using one gram of catalyst. Assuming eight hours of sunlight a day, the scientists estimate that an area measuring 10 x 10 km would be needed to produce hydrogen on an industrial scale.
The researchers say they have managed to pass the milestone of converting 5% of solar energy into hydrogen at room temperature, the threshold at which the technology is considered feasible.

Shirt Repels Liquids, Avoid Stains

Many have dreamed of the day when clothes no longer require washing — or require it far less often than they currently do, at least. With nanotechnology came this reality, though not in any significant way. That could be changing with the introduction of the Silic, a t-shirt that repels liquids and avoids being stained by both liquid substances and sweat.

The shirt is said to be made with hydrophobic nanotechnology, and while such has been achieved in the past, the Silic has one bragging point the others don’t — the substance that gives the clothing its liquid adversion doesn’t disappear if the shirt is washed, meaning the Silic can be tossed in with the rest of the laundry. Beyond that, the folks behind the clothing also say their hydrophobic nanotechnology is not cancerous.
stained T-Shirt
The project is funded through the crowdfundind website Kickstarter, and has already surpassed its funding goal of $20,000 — by a present amount of $112,254 USD. There are 1690 backers at the moment and 33 days to go. $40 is the lowest threshold amount to get one of the shirts, while those who pony up $10 will get a section of the material instead, perhaps good as a bar trick or novelty gift

Source: Kickstarter

Cancer: The Promises Of Nanotechnology

In preclinical trials, nanomaterials have produced safer and more effective imaging and drug delivery, and they have enabled researchers to precisely target tumors while sparing patients’ healthy tissue. In addition, nanotechnology has significantly improved the sensitivity of magnetic resonance imaging, making hard-to-find cancers easier to detect.

A broad spectrum of innovative vehicles is being developed by the cancer nanomedicine community for targeted drug delivery and imaging systems,” said Dr. Ho, author of a new research review published online bye the journal Science Translational Medicine. Ho is co-director of the Jane and Jerry Weintraub Center for Reconstructive Biotechnology at the UCLA School of Dentistry. “It is important to address regulatory issues, overcome manufacturing challenges and outline a strategy for implementing nanomedicine therapies — both individually and in combination — to help achieve widespread acceptance for the clinical use of cancer nanomedicine.

Ho new report features multiple studies in which the use of nanoparticles was translated from the preclinical to the clinical stage. In several of the highlighted studies, nanotechnology-modified drugs showed improvements over conventional, drug-only approaches because of their ability to overcome drug resistance (which occurs when tumors reject the drug and stop responding to treatment), to more effective tumor reduction, among other advantages.

Also described is how algorithm-based methods that rapidly determine the best drug combinations, and computation-based methods that draw information from databases of drug interactions and side effects, to help rationally design drug combinations could potentially be paired with nanomedicine to deliver multiple nano-therapies together to further improve the potency and safety of cancer treatments.
This research review by Dr. Ho and his colleagues lays the groundwork for nanomedicine to become a widely accepted cancer therapy,” said Dr. No-Hee Park, dean of the UCLA School of Dentistry. “This blueprint for navigating the process from bench research to mainstream clinical use is invaluable to the nanotechnology community.”


The Invisible Man Is No More Science Fiction

In the article, ‘Transformation optics and cloaking‘, just published in the academic journal Contemporary Physics, Martin McCall, Professor of Theoretical Optics at Imperial College London, describes how the scientific principles leading to perfect invisibility, or cloaking, are now established. Invisibility, a long sought-for speculation in science fiction, has been turned into reality in the laboratory through the use of a theoretical technique called Transformation Optics. The principles of transformation optics show that any desired smooth deformation of the electromagnetic field can be implemented exactly by an appropriately engineered metamaterial. All demonstrations of cloaking to date have had limitations, however, reflecting our technological inability to implement the transformation optics algorithm exactly.

The scientific principles leading to perfect invisibility are now established, and practical improvements on the initial designs are now occurring very rapidly. Most recently, researchers have re-examined transformation optics to include time as well as space, implementing the concept of a cloak that hides events, a conceptual breakout that promises new applications.

Apart from obvious military possibilities, invisibility research is showing signs of penetrating technology at apparently more mundane, but also more immediate, levels. Transporting and processing optical signals is the basis for global communication, and it is here that we may see the first commercial applications of cloaking technology.


DNA Clamp To Grab Cancer Before It Develops

As part of an international research project, a team of researchers has developed a DNA clamp that can detect mutations at the DNA level with greater efficiency than methods currently in use. Their work could facilitate rapid screening of those diseases that have a genetic basis, such as cancer, and provide new tools for more advanced nanotechnology.
An increasing number of genetic mutations have been identified as risk factors for the development of cancer and many other diseases.

DNA clamps

The results of our study have considerable implications in the area of diagnostics and therapeutics,” says Professor Francesco Ricci from Université de Montreal – Canada -, “because the DNA clamp can be adapted to provide a fluorescent signal in the presence of DNA sequences having mutations with high risk for certain types cancer. The advantage of our fluorescence clamp, compared to other detection methods, is that it allows distinguishing between mutant and non-mutant DNA with much greater efficiency. This information is critical because it tells patients which cancer(s) they are at risk for or have.”

The results of this research is published this month in the journal ACS Nano.

Inkjet-printed Cells From The Eye

A group of researchers from the University of Cambridge have used inkjet printing technology to successfully print cells taken from the eye for the very first time. At the moment the results provide proof-of-principle that an inkjet printer can be used to print two types of cells from the retina of adult rats― ganglion cells and glial cells. This is the first time the technology has been used successfully to print mature central nervous system cells and the results showed that printed cells remained healthy and retained their ability to survive and grow in culture.

The loss of nerve cells in the retina is a feature of many blinding eye diseases. The retina is an exquisitely organised structure where the precise arrangement of cells in relation to one another is critical for effective visual function” said co-authors of the study Professor Keith Martin and Dr Barbara Lorber, from the John van Geest Centre for Brain Repair, University of Cambridge.
Our study has shown that cells derived from the mature central nervous system, the eye, can be printed using a piezoelectric inkjet printer. Although our results are preliminary the aim is to develop this technology for use in retinal repair in the future.


Natural Radioactivity Provokes Genetic Mutation

Curtin University researchers in Australia have shown natural radioactivity within DNA can alter chemical compounds, providing a new pathway for genetic mutation. The research, recently published in Biochimica et Biophysica Acta-General Subjects, for the first time looked at natural radioactivity within human DNA on the atomic-scale.
While radioactivity occurs naturally in our bodies as well as in every living organism across the planet, it was never before thought to affect our DNA in such a direct way. Using high-performance computers, the research team from Curtin and Los Alamos National Laboratory were able to show radioactivity could alter molecular structures which encode genetic information, creating new molecules that do not belong to the four-letter alphabet of DNA. Professor Nigel Marks from Curtin’s Discipline of Physics and Astronomy and Curtin’s Nanochemistry Research Institute said the new molecules may well generate mutations by confusing the replication mechanisms in DNA.

This work takes an entirely new direction on research into natural radioactivity in biology and raises important questions about genetic mutation,” Professor Marks said. “We have discovered a subtle process that could easily be overlooked by the standard cell repair mechanisms in the body, potentially creating a new pathway for mutations to occur.”

Professor Marks said the work was both exciting and unexpected, emerging as a spin-off from an Australian Research Council funded project on nuclear waste.


Alzheimer’s: Amazing News From The Nano World

Alzheimer substance, amyloid, may be the nanomaterial of tomorrow. Amyloid protein causes diseases like Alzheimer’s, Parkinson’s and Creutzfeldt-Jakob . Researchers from Chalmers University of Technology recently unveiled an unexpected discovery about amyloid in an article published in the Nature Photonics journal. Amyloids are misfolded variants of proteins that occur naturally in the body. The researchers have now shown that the misfolded variants react to multiphoton irradiation, a type of laser effect, whereas the healthy proteins do not.

The discovery could be useful in a variety of fields. Not only can it lead to new methods to detect and treat the brain diseases that amyloid causes, amyloid may also be used as a building block for future nanomaterials.
Amyloid proteinAmyloid protein causes diseases like Alzheimer’s, Parkinson’s and Creutzfeldt-Jakob disease. But amyloid also carries unique characteristics that may lead to the development of new composite materials for the nano processors and data storage of tomorrow, and even make objects invisible
It is possible to create these protein aggregates artificially in a laboratory”, says Piotr Hanczyc, one of the researchers who made the discovery. “By combining them with other molecules, one could create materials with unique characteristics.
The amyloid aggregates are as hard and rigid as steel. The difference is that steel is much heavier and has defined material properties, whereas amyloids can be tuned for specific purposes. By attaching a material’s molecules to the dense amyloid, its characteristics change.
“This was already known, but what has not been known is that the amyloids react to multiphoton irradiation”
”, says Piotr Hanczyc. “This opens up new possibilities to also change the nature of the material attached to the amyloids“.

Ultralight, Strong Airplanes

Synthetic, man-made cells and ultrathin electronics built from a new form of “zero-dimensionalcarbon nanotube may be possible through research at the University of Pittsburgh Swanson School of Engineering.

Principal investigators are Steven R. Little, PhD, associate professor, CNG Faculty Fellow and Chair of the Department of Chemical and Petroleum Engineering; and Anna C. Balazs, PhD, the Distinguished Robert v. d. Luft Professor of Chemical and Petroleum Engineering.

Zero Dimensional NanotubesPictured: Piles of zero-dimensional carbon nanotubes appear as gold “mountains” on a substrate by atomic force microscopy. The nanotube mountains are only a few nanometers high – or nearly a billion times smaller than an inch.
Since its discovery, carbon nanotubes have held the promise to revolutionize the field of electronics, material science and even medicine,” says Dr. Little. “Zero-dimensional carbon nanotubes present the possibility to build ultrathin, superfast electronic devices, far superior to the best existing ones and it could be possible to build strong and ultralight cars, bridges, and airplanes.”

The research, ““Zero-Dimensional” Single-Walled Carbon Nanotubes,” was published in the journal Angewandte Chemie.


How To Build Nano-Machines Networks

Networks of nanometer-scale machines offer exciting potential applications in medicine, industry, environmental protection and defense, but until now there’s been one very small problem: the limited capability of nanoscale antennas fabricated from traditional metallic components. With antennas made from conventional materials like copper, communication between low-power nanomachines would be virtually impossible. But by taking advantage of the unique electronic properties of the material known as graphene, researchers now believe they’re on track to connect devices powered by small amounts of scavenged energy.
Based on a honeycomb network of carbon atoms, graphene could generate a type of electronic surface wave that would allow antennas just one micron long and 10 to 100 nanometers wide to do the work of much larger antennas. While operating graphene nano-antennas have yet to be demonstrated, the researchers say their modeling and simulations show that nano-networks using the new approach are feasible with the alternative material.
graphene-antenna-schematicSchematic shows how surface plasmon polariton (SPP) waves would be formed on the surface of tiny antennas fabricated from graphene. The antennas would be about one micron long and 10 to 100 nanometers wide

We are exploiting the peculiar propagation of electrons in graphene to make a very small antenna that can radiate at much lower frequencies than classical metallic antennas of the same size,” said Ian Akyildiz, a Ken Byers Chair professor in Telecommunications in the School of Electrical and Computer Engineering at the Georgia Institute of Technology. “We believe that this is just the beginning of a new networking and communications paradigm based on the use of graphene.”


Solar Powered House For Hours

Converting sunshine into electricity is not difficult, but doing so efficiently and on a large scale is one of the reasons why people still rely on the electric grid and not a national solar cell network. But a team of researchers from the University of Illinois at Urbana-Champaign and the University of Central Florida in Orlando may be one step closer to tapping into the full potential of solar cells. The team found a way to create large sheets of nanotextured, silicon micro-cell arrays that hold the promise of making solar cells lightweight, more efficient, bendable and easy to mass produce. The team used a light-trapping scheme based on a nanoimprinting technique where a polymeric stamp mechanically emboss the nano-scale pattern on to the solar cell without involving further complex lithographic steps. This approach has led to the flexibility researchers have been searching for, making the design ideal for mass manufacturing, said UCF assistant professor Debashis Chanda, lead researcher of the study.

Previously, scientists had suggested designs that showed greater absorption rates of sunlight, but how efficiently that sunlight was converted into electrical energy was unclear, said UCF assistant professor Debashis Chanda, lead researcher of the study. This study demonstrates that the light-trapping scheme offers higher electrical efficiency in a lightweight, flexible module.
The team believes this technology could someday lead to solar-powered homes fueled by cells that are reliable and provide stored energy for hours without interruption.

The study’s findings are the subject of the November cover story of the journal Advanced Energy Materials.