Carbon nanotubes, electrical fields double-team tumors

Since their discovery in 1991, carbon nanotubes have been touted as possible drug delivery devices. But it has taken this long for technology to catch up to the promise. The National Science Foundation's website features the work of Virginia Tech bioengineer Rafael Davalos. He is combining carbon nanotubes with a process called non-thermal irreversible electroporation (N-TIRE), which Davalos co-invented.

With N-TIRE, electrical fields are applied in a targeted tissue area to permanently open pores in cell membranes, causing cell death. He is using N-TIRE to treat the tumor and carbon nanotubes to selectively target cancer cells inside a tumor and cancer cells that have already traveled throughout the body.

"The procedure is essentially done with two minimally invasive (~1 millimeter) electrodes placed into the targeted region," Davalos said, "delivering approximately 80 pulses to the site in about one minute. The pulses are high voltage, but low energy, so no significant heating occurs as a result of the procedure."

The technique does not use heat, so surrounding nerves and major blood vessels are not damaged. However, the big caution is that while N-TIRE has been proven to be effective with minimal side effects, big questions remain about the toxicity of carbon nanotubes. Until that problem is figured out, carbon-nanotube-based therapies are likely to remain on hold.

- read the story on the National Science Foundation website