Dai's team coats carbon nanotubes—hollow cylinders of carbon only a few atoms wide—in folic acid, a molecule that binds with certain types of cancers, including breast cancer. Once the cancer cells absorb the carbon, the researchers fire a near-infrared laser at the cells for two minutes. The beam passes harmlessly through living tissue, but the nanotubes get so hot they roast nearly all of the cancer cells after one exposure.
Last year, researchers at Rice University developed a similar treatment that uses a near-infrared laser to heat nanoshells—microscopic glass beads coated in gold that are too large to be absorbed by healthy cells but small enough to sneak inside tumors through their blood vessels. The Houston-based company Nanospectra has licensed the treatment, and company president Don Payne expects to begin testing it on cancer patients within a year.
Dai's technique must be tested in animals before it can be tried in people. If future experiments do not raise safety concerns, he says, human trials could start in two years.
"Killing Cancer With Red-Hot Nanotubes." To learn more about Hongjie Dai's research, see "Carbon Nanotubes as Multifunctional Biological Transporters and Near-Infrared Agents for Selective Cancer Cell Destruction," Nadine Wong Shi Kam et al. in Proceedings of the National Academy of Sciences, Vol. 102, No. 33, pages 11600–11605; August 16, 2005. www.pnas.org
Read more about research at Dai's laboratory and download recent publications at www.stanford.edu/dept/chemistry/faculty/dai/group.
For more about treating cancer with nanoshells, go to www.nanospectra.com.