Current molecular imaging approaches only detect the cancer but don't offer a method of treatment, according to the study's lead authors, Rebekah Drezek, Ph.D., and Jennifer West, Ph.D., both professors in the Department of Bioengineering at Rice.
"You can look for a molecular marker that may indicate a significant clinical problem, but you can't do anything about it [just through imaging]," says Drezek. "We don't want to simply find the cancerous cells. We would like to locate the cells, be able to make a rational choice about whether they need to be destroyed and, if so, proceed immediately to treatment."
To this end, Drezek and West collaborated to develop a new imaging and treatment method based on metal "nanoshells" - tiny spheres of silica coated with a thin layer of gold. Nanoshells were invented by electrical engineer Naomi Halas, Ph.D., also of Rice University. Because these spheres are constructed on the nanometer scale (one billionth of a meter, the range where molecular interactions take place), they exhibit unique size-dependent behavior, such as tunable optical properties. This allows researchers to design particles that scatter and absorb light at particular wavelengths.
The scattering of light provides the optical signal used to detect the cancer cells, which then "light up" when they come into contact with the nanoshells. In this study, the researchers designed the nanoshells to look for breast cancer biomarkers on the surface of the cancer cells. The technique can be readily extended to target other types of cancer or disease processes that have known surface markers.The additional ability of the
Contact: Michael Bernstein
American Chemical Society