Engineers Develop Cancer-Targeting Nanoprobe Sensors

Research teams around the world have been developing target-specific nanoprobes for the past ten years, but only recently have scientists at the University of California, Berkeley, been able to come up with a mechanism that not only lets the nanoprobes find cancer cells, but also allows them to send information once they have latched onto the target. These new nanocorals, as the scientists have called them, measure a few hundred nanometers in diameter and have roughened gold on one side, and smooth polystyrene on the other. "Like natural corals, the roughened nanocoral surface is designed to capture molecules near the probes, and report their presence back to researchers," said Benjamin Ross, a Ph.D. student in UC Berkeley. The researchers can then figure out how a cell is reacting to a new drug being delivered by the type of molecules present, or absent, at a cell's surface. The sensing side of the nanocorals works by sensing the oscillations the molecules make when exposed to laser light. This process is called surface-enhanced Raman spectroscopy (SERS). The scientists were able to make the nanocorals target specific cells by attaching the appropriate antibodies to the polystyrene side. They demonstrated this concept by attaching a well-known target for breast cancer, antibodies that attack human epidermal growth factor receptor 2 (HER-2), to the nanocorals. The nanocorals then attached themselves to breast cancer cells with HER-2 receptors, while controls showed that there was no binding with different antibodies or with cells lacking HER-2 receptors. The nanocorals are still in early stages of development, but there is hope that these nanocorals will one day be used to "not only deliver a drug, but also to see the response in real time at a sub-cellular level".

http://insciences.org/article.php?article_id=8261#pics