Since their discovery in 1991, carbon nanotubes have been promoted as the solution to many problems - from a strong, small, durable cable for a space elevator, to drug delivery devices. And while a space elevator is still just a dream, there has been real work going on in nanotubes' use in biotech. That work, however, has been bogged down over the years by questions of toxicity. Much is still not known about how carbon nanotubes interact with the body, and these questions are likely to keep nanotubes out of pharmaceuticals until many questions are answered.
Still, there has been some progress on the research front. Researchers in Germany recently used carbon nanotubes as drug depots to deliver the anti-cancer drug carboplatin in vitro. The result: No significant intrinsic toxicity of the materials were found. And the carboplatin that was delivered by carbon nanotubes exhibited higher anticancer activity than free carboplatin. Article
Because of their size, strength and other properties, nanotubes have made for some handy tips to sensitive instruments like high-powered microscopes. Recently, researchers at Drexel University in Philadelphia combined nanotubes with another old standby of the nanotech world, the quantum dot. They used it to solve a problem of how to observe cells without damaging the cells being observed. The researchers used a nanotube-based device, known as a cellular endoscope, to evaluate cells and deliver fluorescent quantum dots all without the cells even knowing they're being probed. Article
Another researcher, this one at Virginia Tech, is combining carbon nanotubes with electrical fields in a process called non-thermal irreversible electroporation (N-TIRE). With N-TIRE, electrical fields are applied in a targeted tissue area to permanently open pores in cell membranes, causing cell death. The researcher then uses N-TIRE to treat the tumor and carbon nanotubes to selectively target cancer cells inside. Article
The big question with N-TIRE and any other device or therapeutic that contains nanotubes, is how toxic is it, and whether the tubes can be treated to lessen their toxicity. Until those problems are figured out, carbon-nanotube-based therapies are likely to remain in the lab only.