Medical devices like implanted arteries or external dialysis machines keep people alive. But persistent problems exist. Blood flowing through the tubes can form dangerous clots. And bacteria that stick to surfaces could start infections.
Treatment for patients using such devices thus often includes anticlotting agents such as heparin. But such substances have their own risk: by interfering with clotting, they can cause potentially deadly bleeding.
Recently, researchers at the Wyss Institute for Biologically Inspired Engineering at Harvard University looked to the carnivorous pitcher plant for guidance. The plant’s structure includes wells with surfaces too slippery for insects to crawl out of. Those surfaces inspired the development of a coating so slippery that it prevents blood and bacteria from sticking.
The team tested the coating on the interiors of tubes and catheters attached to pigs. They demonstrated that the coating did not degrade, and that blood kept flowing without clotting, for eight hours. Blood usually starts to clot in tubes in an hour. The study is in the journal Nature Biotechnology. [Daniel C. Leslie et al, A bioinspired omniphobic surface coating on medical devices prevents thrombosis and biofouling]
The researchers also tested whether a gecko could latch onto the coating with its notoriously sticky footpads. But not even the gecko could get a grip.
—Cynthia Graber
