Efforts to control biofouling—the spontaneous and unwanted adsorption of proteins, cells, and bacteria on surfaces—may have another tool in the form of a new class of polymers that mimic polypeptides, according to a recent study by Northwestern University researchers. Biofouling is a serious problem in health care and other arenas. It causes malfunction of medical implants and diagnostic devices, exposes patients to infections and complications, and increases the cost of treatment.

The new polymers consist of a short “anchoring peptide” and a variable-length N-substituted glycine oligomer (J. Am. Chem. Soc., published online May 13, dx.doi.org/10.1021/ja0522534). The design—by Phillip B. Messersmith, associate professor of biomedical engineering; Annelise E. Barron, associate professor of chemical and biological engineering; and coworkers—enables the polymer to stick to a surface robustly while preventing proteins and cells from sticking to it.

The polymer shown is an example of the new class. It consists of an anchoring peptide that mimics an adhesive protein from marine mussels that is attached to a chain of 20 N-methoxyethylglycines, which provides resistance to protein and cell fouling.

The team demonstrated that titanium surfaces coated with this polymer adsorbed significantly less protein than did bare titanium. The coating maintained its protein and cell resistance over several months. Coatings made from such polymers could help prevent fouling in physiological, marine, and industrial environments, the researchers say.