Washington, November 2 : Radio waves have been found to offer a non-invasive method to destroy cancer cells treated with carbon nanotubes in pre-clinical experiments led by scientists at the University of Texas M. D. Anderson Cancer Center and Rice University.

Writing about their findings in the journal Cancer, the researchers said that radio waves that heat up the nanotubes while sparing untreated tissue enabled them to destroy liver cancer tumours in rabbits completely.

The technique did not produce any side effects, though some healthy liver tissue within two to five millimetres of the tumours sustained heat damage due to nanotube leakage from the tumour.

"These are promising, even exciting, pre-clinical results in this liver cancer model. Our next step is to look at ways to more precisely target the nanotubes so they attach to, and are taken up by, cancer cells while avoiding normal tissue," says senior study author Dr. Steven Curley, professor in M. D. Anderson's Department of Surgical Oncology.

He believes that targeting the nanotubes solely to cancer cells is the major challenge in advancing the therapy, and reckons that a clinical trial is at least three to four years away.

During the study, a solution of single-walled carbon nanotubes was injected directly into the tumours. The researchers then exposed the four treated rabbits to two minutes of radiofrequency treatment, resulting in thermal destruction of their tumours.

Control group tumours that were treated only by radiofrequency exposure or only by nanotubes remained undamaged.

In laboratory experiments, two lines of liver cancer cells and one pancreatic cancer cell line were destroyed after being incubated with nanotubes and exposed to the radiofrequency field.

"I'm humbled by the results of this research. I realize it's early in the race, but Dr. Curley and his team have moved on this carefully with utmost speed. I look forward to continuing to work with them and hopefully to watching the first person be treated with this procedure. The race isn't over but it needs to be taken to the finish line," says entrepreneur John Kanzius of ThermMed LLC, who invented the experimental radiofrequency generator used in the experiments.

Dr. Curley says that radiofrequency energy fields penetrate deeply into tissue, and thus it may be possible to deliver heat anywhere in the body if targeted nanotubes or other nanoparticles can be delivered to cancerous cells.

Without such a target, radio waves will pass harmlessly through the body, he adds. (ANI)