Last year, the father and son research team of Mostafa El-Sayed and Ivan El-Sayed, showed that gold nanoparticles coated with a cancer antibody were very effective at binding to tumor cells. When bound to the gold, the cancer cells scattered light, making it very easy to identify the noncancerous cells from the malignant ones. The nanoparticles also absorbed the laser light more easily, so that the coated malignant cells only required half the laser energy to be killed compared to the benign cells. This makes it relatively easy to ensure that only the malignant cells are being destroyed.
Now, they've discovered that by changing the spheres into rods, they can lower the frequency to which the nanoparticles respond from the visible light spectrum used by the nanospheres to the near-infrared spectrum. Since these lasers can penetrate deeper under the skin than lasers in the visible spectrum, they can reach tumors that are inaccessible to visible lasers.
"With the nanospheres we're using visible lasers, but most of the solid cancer is under the tissues and visible light doesn't go but a few millimeters deep. But by using the nanorods we can tune them to react to the infrared lasers, which can penetrate the tumor without being absorbed by the tissues," said Mostafa El-Sayed, director of the Laser Dyanamics Laboratory and Regents' professor of
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Contact: David Terraso
d.terraso@gatech.edu
404-385-2966
Georgia Institute of Technology
14-Mar-2006