Fibrin formation and fractal organization at cationic, anionic, and zwitterionic polymer coated interfaces.

Abstract

Biomaterial-associated thrombosis remains a persistent challenge whenever medical devices are inserted in blood vessels. The issue is principally addressed by the development of antithrombogenic coatings that prevent the formation of blood clots, <i>e.g.</i> by limiting adsorption of fibrin - the core protein network of a clot. Charged polymers (<i>i.e.</i> polyelectrolytes and zwitterionic polymers) show potential as coating materials for medical devices, and we here investigate these polymer coatings in the context of biomaterial-associated thrombosis. Our findings indicate that fibrin polymerization can yield a surface-dependent distribution of fractal-like branched structures and amorphous aggregates, with surface-induced fibrin formation dominating for anionic polymer interfaces and recruitment of bulk-formed fibrin dominating for cationic polymer interfaces. In addition, we identify coatings containing zwitterionic sulfobetaine groups as promising candidates for antithrombogenic biomaterials.