Nanospheres fry cancer cells

Researchers have developed special hollow gold nanospheres - particles smaller than the finest flecks of dust - that seek out and destroy cancer cells.

The cancer-destroying nanospheres show particular promise as a minimally invasive future treatment for malignant melanoma, a deadly form of skin cancer, a researcher involved in the work reported this week at the American Chemical Society meeting underway in Salt Lake City.

The hollow gold nanospheres are equipped with a special peptide targeting a protein receptor on melanoma cells. That protein fragment draws the nanospheres directly to melanoma cells, while avoiding healthy skin cells. Once inside the tumor, the nanospheres heat up when exposed to near-infrared light, which penetrates the surface of the skin.

8 times more damage
In recent studies in mice, the hollow gold nanospheres did eight times more damage to skin tumors than the same nanospheres without the targeting peptides.

"This technique is very promising and exciting," study co-author Dr Jin Zhang, a professor of chemistry and biochemistry at the University of California in Santa Cruz, noted in a statement from the meeting.

"It's basically like putting a cancer cell in hot water and boiling it to death. The more heat the metal nanospheres generate, the better," Zhang said.

This form of cancer therapy is a variation of photothermal ablation, also known as photoablation therapy - a technique in which doctors use light to burn tumors. Since the technique can destroy healthy skin cells, doctors must carefully control the duration and intensity of treatment.

Zhang said the long-term goals of his research are to ensure safety of the treatment, followed by human clinical trials. – (Reuters Health, March 2009)