Laser Treatment Kills Cancer Cells   

A NANOTECH-laser treatment that can destroy cancer cells without damaging healthy tissue has been developed by Stanford University scientists.

The scientists placed a solution of carbon nanotubes -- synthetic rods that are only half the width of a DNA molecule -- under an infrared laser beam. The laser beam heated the carbon nanotube solution to about 158 degrees Fahrenheit within two minutes.

When nanotubes were placed inside cells and radiated by the laser beam, the cells were quickly destroyed by the heat. However, cells that did not contain any nanotubes were not affected by the laser beam.

"An interesting property of carbon nanotubes is that they absorb near-infrared light waves, which are slightly longer than visible rays of light and pass harmlessly through our cells," study co-author Hongjie Dai, associate professor of chemistry at Stanford, said in a prepared statement.

When the carbon nanotubes absorb near-infrared light waves, electrons in the nanotubes become excited and release excess energy in the form of heat, Dai said.

"It's actually quite simple and amazing. We're using an intrinsic property of nanotubes to develop a weapon that kills cancer," Dai said.

The study appears in the Aug. 1 online edition of the journal Proceedings of the National Academy of Sciences.

"One of the longstanding problems in medicine is how to cure cancer without harming normal body tissue. Standard chemotherapy destroys cancer cells and normal cells alike.

That's why patients often lose their hair and suffer numerous other side effects. For us, the Holy Grail would be finding a way to selectively kill cancer cells and not damage healthy ones," Dai said.●