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Wednesday, April 14, 2010

Buckyballs can be toxic


Fullerenes, also known as ‘buckyballs’ or ‘buckminster fullerenes’ all after the late Buckminster Fuller, are spherical molecules composed of carbon atoms. Fullerenes are interesting because the carbon atoms form a molecular cage that can be used to transport drugs or other chemicals into living tissues. The balls themselves were assumed to be biologically inert. Rashi Iyer and his team from Los Alamos National Laboratory put that assumption to the test. They found that certain fullerene derivatives are actually toxic.

Specifically, the team tested fullerene C60 (a molecule composed of 60 carbon atoms), hexa carboxyl fullerene (hexa-C60, a variation with six molecular branches coming off one hemisphere of the ball), and tris carboxyl fullerene (tris-C60, another variation with only three molecular branches). Upon applying the three types of fullerenes to human skin cells, they found that the tris configuration caused premature senescence in the cells, but that the plain or hexa configurations had no effect.

Senescence in cells is basically a shutting down of the cell cycle. Although the cells aren’t technically dead, they don’t perform any of their cellular functions. Obviously, this is not generally a desired result of treatment. For this reason, the researchers suggest that therapists avoid using tris-C60 as delivery molecules. On the other hand, there are certain diseases, such as Parkinson’s in which nerve cells die or degenerate prematurely. Perhaps putting these damaged nerve cells into premature senescence might actually be helpful.

Clearly more research should must be done. For one thing, cells in tissue culture don't always behave the same way as cells within a living body. Los Alamos National Laboratory plans to continue studying exposure to nanomaterials.