Stanford University researchers have succeeded in functionalising carbon nanotubes to carry anti-cancer drugs to tumours while avoiding damage to healthy tissues. The research, led by Professor Hongjie Dai, takes advantage of the so-called “leaky vasculature” of tumour blood vessels. Carbon nanotubes of dimensions of about 100 nm in length and several nm in diameter can pass through these leaky vessels but not through the tight cell junctions of normal blood vessels.

Prof. Dai and fellow researchers coated the carbon nanotubes with polyethylene glycol (PEG) which is able to carry a molecule of the drug paclitaxel on each of its three end branches. Each carbon nanotube was able to carry around 150 molecules of the drug. PEG also has the property of allowing the novel delivery system to survive for a relatively long time in the bloodstream thereby facilitating the particles finding and destroying tumour cells.

While results have been promising further research is still needed, particularly to characterise the potential toxic effects of the carbon nanotubes and their method of removal from the body.

Full story available at MIT Technology Review.

Posted: August 29th, 2008 under Nanomedicine.
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Researchers at the University of North Carolina have suggested that manufacturing therapeutic nanoparticles so that they have similar shapes to bacteria could aid their uptake into cells and therefore more effective at treating diseases

The team, led by Professor Joseph DeSimone found that longer, rod-shaped nanoparticles resembling some pathogenic bacteria were able to enter cells at four times the rate of shorter, more cylindrically-shaped particles of a similar volume. The finding follows earlier work at the same lab where Professor DeSimone’s team succeeded in developing a method to manufacture large numbers of nanoparticles in various shapes and sizes in contrast to the spherical particles so far used in most applications. The team is now carrying out further studies with different sizes and shaps of particles, and different doses of drugs to determine the least toxic and most effective combinations.

In another line of research Professor DeSimone has developed microparticles that mimic red blood cells in size, shape and flexibility and other long, wormlike particles that are less liable to being ingested by macrophages.

Full story at MIT Technology Review.

Posted: August 12th, 2008 under Nanomedicine, Nanotechnology.
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