BOB HIRSHON (host):
Ivy-league sunscreens…I’m Bob Hirshon and this is Science Update.
The sticky stuff that helps ivy climb walls may also improve sunscreens. This according to work by biomedical engineer Mingjun Zhang of the University of Tennessee at Knoxville and his colleagues. Two years ago, Zhang’s team analyzed ivy secretions to figure out how the vines stick to walls. They found lots of different nano-particles, or tiny chemical chunks, in the secretions.
Meanwhile, other scientists were raising concerns about the long-term health risks of metal-based nano-particles found in today’s sunscreens. Because all nano-particles have built-in optical properties, Zhang wondered if the natural particles from ivy might be safer. He found that the ivy nano-particles are less toxic to cells, less likely to be absorbed into the skin, and actually block ultraviolet light better than the metal ones. I’m Bob Hirshon, for AAAS, the science society.