Mussel glue inspires coating for medical implants.

Many medical implants, such as catheters, stents, and other cardiovascular devices, fail because cells stick to them and interfere with their operation. Although researchers have tried coating these devices with antifouling polymers, the coats tend to be susceptible to enzymatic degradation and often peel off. However, a new coating inspired by the adhesive secreted by mussels could be more durable.

A group led by Phillip Messersmith of Northwestern University in Evanston, Ill., synthesized an antifouling material consisting of two linked parts. The first part is a proteinlike polymer designed to prevent cells from sticking to it. The polymer also is resistant to enzymatic degradation and doesn't elicit immune responses, says Northwestern team member Andrea Statz. Attached to this polymer is a second component, one that emulates the adhesive protein in mussel glue. In tests on titanium dioxide, a common implant material, the antifouling coating stuck fast.

Cell tests also were promising. After 20 weeks of sitting in a solution containing mouse cells, the new coating had few of the cells adhering to it. Without the coating, a titanium dioxide surface became covered with cells.--A.G.