Comparison study of surface-initiated hydrogel coatings with distinct side-chains for improving biocompatibility of polymeric heart valves

Abstract

Polymeric heart valves (PHVs) present a promising alternative for treating valvular heart diseases with satisfactory hydrodynamics and durability against structural degeneration. However, the cascaded coagulation, inflammatory responses, and calcification in the dynamic blood environment pose significant challenges to the surface design of current PHVs. In this study, we employed a surface-initiated polymerization method to modify polystyrene-block-isobutylene-block-styrene (SIBS) by creating three hydrogel coatings: poly(2-methacryloyloxy ethyl phosphorylcholine) (pMPC), poly(2-acrylamido-2-methylpropanesulfonic acid) (pAMPS), and poly(2-hydroxyethyl methacrylate) (pHEMA). These hydrogel coatings dramatically promoted SIBS's hydrophilicity and blood compatibility at the initial state. Notably, the pMPC and pAMPS coatings maintained a considerable platelet resistance performance after 12 h of sonication and 10 000 cycles of stretching and bending. However, the sonication process induced visible damage to the pHEMA coating and attenuated the anti-coagulation property. Furthermore, the in vivo subcutaneous implantation studies demonstrated that the amphiphilic pMPC coating showed superior anti-inflammatory and anti-calcification properties. Considering the remarkable stability and optimal biocompatibility, the amphiphilic pMPC coating constructed by surface-initiated polymerization holds promising potential for modifying PHVs.