This scanning electron microscope image shows how red blood cells coagulate to form a blood clot. (Credit: James Weaver, Harvard’s Wyss Institute)
Any medical device implanted in the body or in contact with flowing blood faces two critical challenges: blood clotting and bacterial infection. Now, a team of scientists at the Wyss Institute for Biologically Inspired Engineering at Harvard, Boston, say they have developed a new surface coating for medical devices using FDA-approved materials that not only repelled blood from more than 20 medically relevant substrates the team tested, but also suppressed biofilm formation. The team’s implanted medical-grade tubing and catheters coated with the material prevented blood from clotting for at least eight hours without the use of blood thinners, such as heparin. This super-repellent coating can be adhered to existing, approved medical devices, they say.

The idea for the coating evolved from Slippery Liquid–Infused Porous Surfaces (SLIPS), a pioneering surface technology developed at Harvard. Inspired by the carnivorous pitcher plant, SLIPS repels nearly any material it contacts. The liquid layer on the surface provides a barrier to everything from ice to crude oil and blood.

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