A phospholipid-modified polystyrene-polyisobutylene-polystyrene (SIBS) triblock polymer for enhanced hemocompatibility and potential use in artificial heart valves

Poly(styrene-block-isobutylene-block-styrene) (`SIBS') is selected for a novel trileaflet heart valve due to its high resistance to oxidation, hydrolysis, and enzyme attack. SIBS is modified using six different phospholipids and its mechanical properties characterized by tensile stress, peel strength, shear strength, contact angle, and surface energy, and then for hemocompatibility by studying the adhesion of fluorescently labeled platelets in a parallel plate chamber under physiological flow conditions. Phospholipid modification decreases SIBS tensile stress (at 45% strain) by 30% and reduces platelet adhesion by a factor of 10, thereby improving its hemocompatibility and its potential use as a synthetic heart valve.