Bioinspired coating for medical devices repels blood and bacteria

From joint replacements to cardiac implants and dialysis machines, medical devices enhance or save lives on a daily basis.

However, any device implanted in the body or in contact with flowing blood faces two critical challenges that can threaten the life of the patient the device is meant to help: blood clotting and bacterial infection.

A team of Harvard scientists and engineers may have a solution. They developed a new surface coating for medical devices using materials already approved by the Food and Drug Administration (FDA). The coating repelled blood from more than 20 medically relevant substrates the team tested – made of plastic to glass and metal – and also suppressed biofilm formation in a study reported in Nature Biotechnology. But that's not all.

The team implanted medical-grade tubing and catheters coated with the material in large blood vessels in pigs, and it prevented blood from clotting for at least eight hours without the use of blood thinners such as heparin. Heparin is notorious for causing potentially lethal side-effects like excessive bleeding but is often a necessary evil in medical treatments where clotting is a risk.

"Devising a way to prevent blood clotting without using anticoagulants is one of the holy grails in medicine," said Don Ingber, M.D., Ph.D., Founding Director of Harvard's Wyss Institute for Biologically Inspired Engineering and senior author of the study.