Cornell University researchers led by Professor Carl Batt said the nanoparticles are made of gold sandwiched between two pieces of iron oxide. Antibodies that target a molecule found only in colorectal cancer cells is then attached. Once bound, the nanoparticles are engulfed by the cancer cells.
To kill the cells, the researchers said they used a near-infrared laser, which is a wavelength that doesn't harm normal tissue at the levels used. But the radiation is absorbed by the gold in the nanoparticles. That causes the cancer cells to become heated and die.
"This is a so-called 'smart' therapy," Batt said. "To be a smart therapy, it should be targeted, and it should have some ability to be activated only when it's there and then kills just the cancer cells."
The goal, said lead author and biomedical graduate student Dickson Kirui, is to improve the technology and make it suitable for testing in a human clinical trial. The researchers are now working on a similar experiment targeting prostate cancer cells.
The research appeared in the Feb. 15 online edition of the journal Nanotechnology.