Detox for nanotubes

In follow-on work to last year's toxicological study on water-soluble buckyballs, researchers at

Center for Biological and Environmental Nanotechnology (CBEN) find that water-soluble carbon nanotubes are significantly less toxic to begin with. Moreover, the research finds that nanotubes, like buckyballs, can be rendered nontoxic with minor chemical modifications.

The findings come from the first toxicological studies of water-soluble carbon nanotubes. The study will be published in an upcoming issue of the journal Toxicology Letters.

"Carbon nanotubes are high-profile nanoparticles that are under consideration for dozens of applications in materials science, electronics and medical imaging," said CBEN Director Vicki Colvin, the lead researcher on the project. "For medical applications, it is reassuring to see that the cytotoxicity of nanotubes is low and can be further reduced with simple chemical changes."

Research has been conducted on the toxicity of carbon nanotubes, but CBEN's is the first to examine the cytotoxicity of water-soluble forms of the hollow carbon molecules. In their native state, carbon nanotubes are insoluble, meaning they are incompatible with the water-based environment of living systems. Solubility is a key issue for medical applications, and researchers at Rice and elsewhere have developed processing methods that render nanotubes soluble. In particular, scientists are keen to exploit the fluorescent properties of carbon nanotubes for medical diagnostics.