Improved antifouling and drug delivery properties of polyvinyl alcohol hydrogel by grafting with N-isopropylacrylamide via organic dye photocatalyzed PET-RAFT polymerization

Polyvinyl alcohol (PVA) hydrogel was modified with NIPAAm via a green, efficient, and industrially applicable photo induced electron transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization catalyzed by organic dye. The hydrophilicity of PVA-g-pNIPAAm became temperature sensitive due to the introduction of pNIPAAm polymer brushes. It was surprising that PVA-g-pNIPAAm became superhydrophilic (WCA = 4.3°) at 25°C while the grafting yield was 39.3%. In addition, no cytotoxic for primary human eyelid fibroblast cells was observed according to ISO 10993.5:2009. Antifouling properties of PVA-g-pNIPAAm were significantly improved due to the increase of surface steric repulsion effect. Drug release property of PVA-g-pNIPAAm was more controllable than PVA hydrogel. Thus, organic dye catalyzed PET-RAFT polymerization could be applied to construct functional surface on biomaterials, and PVA-g-pNIPAAm hydrogel with lower cytotoxic, higher antifouling, and drug release properties had great potential in drug delivery.