Primate study provides positive sign for the safety of nanomedicine. Nanomedicine is a hugely promising field, but while remarkable new treatments and diagnostic tests are being developed, questions remain about the long term effects of nanoparticles on our bodies. Adding to our understanding of these issues, researchers have now reported that the use of quantum dots - tiny luminescent crystals that can be used to monitor disease at a cellular level - appears to be safe in primates over a one-year period. The toxicity study was conducted by the University at Buffalo (UB), the Chinese PLA General Hospital, China's ChangChun University of Science and Technology, and Singapore's Nanyang Technological University. With the aim of accessing the effect of quantum dots on humans, the study saw four rhesus monkeys injected with cadmium-selenide quantum dots.
The findings showed that the" acute toxicity of these quantum dots in vivo can be minimal" with the monkeys remaining in normal health over 90 days. Crystals connect like LEGO bricks. This video gives an impression of how nanoparticles connect to form larger crystals. Nanoparticles are tiny crystals. In liquid they move around more or less randomly. Studies of dry crystals, on the other hand, have indicated that while in liquid the crystal grew by means of the nanoparticles finding a spot where their crystal lattices match perfectly and making a so-called oriented attachment. This is similar to a LEGO brick that fits perfectly on top of another.
One could imagine the nanoparticles as microscopic LEGO bricks, where the pins are positively charged atoms and the holes are negatively charged atoms. At a certain point they are in perfect alignment, and the strong attraction between the two opposing charges makes the bricks connect to form a larger crystal. Self-assembling LEGO bricks An illustration of crystal growth by perfect attachment of nanoparticles in a liquid solution. Up to now it has not been possible to observe this process by studying dry crystals.
Photoreactive Azido-Containing Silica Nanoparticle/Polycation Multilayers: Durable Superhydrophobic Coating on Cotton Fabrics - Langmuir. Australian Future Fibres Research and Innovation Centre, Deakin University, Geelong VIC 3217, Australia Langmuir, 2012, 28 (15), pp 6328–6335 DOI: 10.1021/la300281q Publication Date (Web): April 1, 2012 Copyright © 2012 American Chemical Society Section: Abstract In this study, we report the functionalization of silica nanoparticles with highly photoreactive phenyl azido groups and their utility as a negatively charged building block for layer-by-layer (LbL) electrostatic assembly to produce a stable silica nanoparticle coating.
Citing Articles View all 21 citing articles Citation data is made available by participants in CrossRef's Cited-by Linking service. This article has been cited by 3 ACS Journal articles (3 most recent appear below). Www.fas.org/sgp/crs/misc/RL34511.pdf. Reusable oil-absorbing nanosponges could soak up oil spills. Last week we looked at the development of “hydrate-phobic” surfaces that could assist in the containment of oil leaks in deep water. Now, by adding boron to carbon while growing nanotubes, researchers have developed a nanosponge with the ability to absorb oil spilled in water.
Remarkably, the material is able to achieve this feat repeatedly and is also electrically conductive and can be manipulated with magnets. While multiwalled carbon nanotubes grown on a substrate via chemical vapor disposition form standing up without any real connections to their neighbors, the researchers found that adding a dash of boron to the nanotube production process puts kinks and elbows into them as they grow and promotes the formation of covalent bonds. This gives the nanosponges, which are 99% air, an elastic property that is retained even after 10,000 compressions in the lab.
However, the researchers believe environmental cleanup applications are just the tip of the iceberg for the material. Nanotech greatly reduces leaching in pressure-treated lumber. Pressure-treated lumber has been shown to leach much less preservatives, when treated using a newly-developed technology When people are building things such as decks or fences, they often use lumber that has been pressure-treated with preservatives. While this does indeed help the wood last longer, the chemicals will gradually leach out into the ground, harming organisms within it. Now, however, researchers have found a way of using nanotechnology to keep the preservatives in the wood.
The scientists, from Michigan Technological University, encapsulated tiny droplets of the fungicide tebuconazole within spherical nanoparticles. The spheres were chemically modified to work with the fungicide, and were made from either gelatin or chitosan – the latter material is derived from chitin, the main component of the exoskeleton of crustaceans, and has been used in everything from self-healing paint to a flu virus filter to a biocompatible transistor.
Source: Michigan Tech About the Author. Nanoparticles impact fish through the food chain. A new study shows nanoparticles can harm fish by surviving several links in the food chain. (Photo: iStockphoto) A new Swedish study shows that nanoparticles can survive several links in the food chain. Algae were grown in a tank of water containing nanoparticles. The algae absorbed these particles, The algae were then fed to animal plankton, and finally the plankton was fed to fish. The behaviour of the fish that consumed these zooplankton changed. The fish simply lost their appetites. Stopped chasing plankton “The fish stopped eating and searching for food,” says researcher Tommy Cedervall, of the University of Lund in Sweden. Researcher Tommy Cedervall (Photo: Lunds University) Scientists found it remarkable that the fish let zooplankton swim in and out of their mouths without even trying to eat them. When placed on a moderate diet, the fish that had been exposed to zooplankton containing nanoparticles didn’t lose weight, according to the article in the journal PLoS One.
Hampers metabolism. Cyborg snail gets biofuel cell implant. The cyborg snail with a biofuel cell implant that generates electrical power from glucose and oxygen in the snail's blood Earlier this year we reported that researchers had implanted a cockroach with an enzyme-based biofuel cell that could potentially be used to power various sensors, recording devices, or electronics used to control an insect cyborg. While it may not be the most dynamic of creatures, a team from Clarkson University has now performed a similar feat with a living snail. The biofuel cell implanted into the snail by a team led by Evgeny Katz, the Milton Kerker Chaired Professor of Colloid Science at Clarkson University, was able to operate continuously producing electrical power for most of the snail's six month lifespan, using only the snail’s physiologically produced glucose and oxygen in the snail’s blood as a fuel.
The team says the implanted biofuel cell would be able to operate in a natural environment, making it suitable for powering various bioelectronics devices. A Nanotech Teabag Delivers Potable Water for Less than a Cent - Environment - GOOD. Institute of Nanotechnology. Carbon Nanotubes. Transmission electron microscopy of carbon nanotubes: a warning.
Carbon nanotube science and technology Carbon nanotubes are molecular-scale tubes of graphitic carbon with outstanding properties. They are among the stiffest and strongest fibres known, and have remarkable electronic properties and many other unique characteristics. For these reasons they have attracted huge academic and industrial interest, with thousands of papers on nanotubes being published every year. Commercial applications have been rather slow to develop, however, primarily because of the high production costs of the best quality nanotubes. The current huge interest in carbon nanotubes is a direct consequence of the synthesis of buckminsterfullerene, C60 , and other fullerenes, in 1985. A transmission electron micrograph of some multiwalled nanotubes is shown in the figure (left).
Structure The bonding in carbon nanotubes is sp, with each atom joined to three neighbours, as in graphite. Synthesis Properties Nanohorns. Nanotechnology is coming. By Ralph C. Merkle, Principal Fellow, Zyvex This is the English original of an article translated into German and published in the Frankfurter Allgemeine Zeitung of Monday, September 11 2000 on page 55. In the coming decades nanotechnology could make a supercomputer so small it could barely be seen in a light microscope. Fleets of medical nanorobots smaller than a cell could roam our bodies eliminating bacteria, clearing out clogged arteries, and reversing the ravages of old age. Clean factories could eliminate pollution caused by manufacturing. Low cost solar cells and batteries could replace coal, oil and nuclear fuels with clean, cheap and abundant solar power.
Not long ago, such a forecast would have been ridiculed. At its heart, the coming revolution in manufacturing is a continuation of trends that date back decades and even centuries. The remarkably low manufacturing cost comes from self replication. Self replication is at the heart of many policy discussions. Further reading: