The research appears in the Dec. 8 issue of the Journal of the American Chemical Society. It suggests that the white blood cells, which were incubated in dilute solutions of nanotubes, treated the nanotubes as they would other extracellular particles actively ingesting them and sealing them off inside chambers known as phagosomes.
"Our goal in doing the experiment was both to learn how the biological function of the cells was affected by the nanotubes and to see if the fluorescent properties of the nanotubes would change inside a living cell," said lead researcher Bruce Weisman, professor of chemistry at Rice. "On the first point, we found no adverse effects on the cells, and on the second, we found that the nanotubes retained their unique optical properties, which allowed us to use a specialized microscope tuned to the near-infrared to pinpoint their locations within the cells."
The research builds upon Weisman's groundbreaking 2002 discovery that each of the dozens of varieties of semiconducting, single-walled carbon nanotubes (SWNTs) emits its own unique fluorescent signature.
The new findings suggest that SWNTs might be valuable biological imaging agents, in part because SWNTs fluoresce in the near-infrared portion of the spectrum, at wavelengths not normally emitted by biological tissues. This may allow light from even a handful of nanotubes to be selectively detected from within the body.
Carbon nanotubes are cylinders of carbon atoms that measure about one nanometer, or one-billionth of a meter, in diameter. They are larger than a molecule of water, but are about
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