MIT-Harvard scientists have developed a novel system where superparamagnetic nanoparticles can deliver drugs by means of customisable DNA tethers that release the drug when exposed to a low-frequency electromagnetic field. When the paramagnetic particles are exposed to the field they heat causing the hydrogen bonds in the DNA tethers to break, releasing the drug payload. Different lengths and differently coded-strands of DNA require different amounts of heat to break, therefore enable the system to be tuned for different drug payloads. 

The team, led by Dr Sangeeta Bhatia and Geoff von Maltzahn are now working on solutions to ensure that the particles clump together at the site of a tumour, a pre-requisite for future human cancery therapy applications.

Full story at the Physorg website.

Posted: November 19th, 2007 under Nanomedicine.
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New research at Northwestern University suggests that nanodiamonds could be useful in targeting chemotherapeutic drugs and other drugs to their target sites and preventing damage to normal cells.

The team, led by Dr Dean Ho, manipulated single nanodiamonds around 2nm in diameter to form aggregates of around 50 to 100 nm. The drug is loaded onto the surface of the individual diamonds but only becomes active once the aggregate breaks apart at its target site. The bare nanodiamonds that are left appear, due to their ordered structure, not to cause cell inflammation like some other delivery materials. Up to five times the amount of drug can be carried, due to the large surface area, than is possible with conventional materials and the nanodiamonds are also soluble in water.

For further information see the Physorg website.

Posted: November 12th, 2007 under Nanomedicine.
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Intel has launched its new 45nm feature chip, named Penryn. Using a new hafnium-based gate, the processors incorporate 420 million transistors on each dual-core chip and 840 million on each quad-core chip. The scale is such that 30 million of the transistors would fit on the head of a pin.

Hafnium is a so-called high-K material and has a greater ability to store electrical charge than a similar design using silicon dioxide, thereby overcoming current leakage problems that would otherwise reduce the effectiveness of the chip.

Several manufacturers have already announced that they will use the new Penryn processors in top-of-the-line personal computers.

As previously reported on Ten to the Minus Nine, Intel’s next generation chips, planned for 2009, will incorporate features down to 32nm and will also be based on a hafnium high-K insulator.

More details at the BBC News Technology website.

Posted: November 12th, 2007 under Physics, Nanotechnology.
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New developments in “spintronics” (also  called spin-based electronics or magnetoelectronics) which exploits the quantum spin states of electrons as well as there charge state may soon render current hard drives look massive according to Albert Fert, co-winner of the 2007 Nobel Prize for Physics. Fert is a co-discoverer of giant magnetoresistance which heralded the birth of spintronics.

Many believe that spintronic devices represent a future multi-billion industry and could lead to the development of quantum-based microchips. So-called magnetic random access memory  (MRAM) described by Fert and colleagues could lead to a new era of computing where computer chips and disk drives could be collapsed into one device with massively increased processing power and storage capacity, and access times for reading/writing of information down to five nanoseconds.

The development of such devices is part of an ongoing revolution enabled by nanoscale innovations in materials, moving from silicon to metals and other materials within the transistor gate and “bottom-up” assembled nanotubes and nanowires in electronic circuits.

Further information at the Physorg website.

Posted: November 5th, 2007 under Physics, Nanotechnology.
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