Surface Modification of Polymeric Materials with Antifouling Polymer Brushes Based on a Photo-fixable Initiator

Surface grafting of hydrophilic polymer brushes is an important strategy to endow the biomedical polymer materials with anti-fouling property. Immobilization of initiator is the core procedure of this strategy, which is expected to be fast and versatile. In this study, a new UV-fixable initiator is designed, which is universal for a wide range of polymeric substrates and monomers to polymerize. The initiator contains a benzophenone structure for UV immobilization on various polymeric substrates, and two bromine initiator termini, which have the potent to graft high-density polymer brushes through the single electron transfer living radical polymerization (SET-LRP). The method was first carried out by grafting poly(oligo(ethylene glycol) methyl ether acrylate) (POEGA) brush on the poly(vinyl chloride) (PVC) surface. Fibrinogen (Fg) adsorption results showed that the modified surface has good protein-resistant properties. The POEGA brush with the polymerization time of 2 hours has the lowest amount of Fg adsorption. The results of cell adhesion experiments showed that the modified surface can effectively inhibit the adhesion of Hela cells and Staphylococcus aureus. The universality of the method was further studied on different substrates and using different hydrophilic monomers. It was showed that the UVfixable initiator can be applied to polydimethylsiloxane (PDMS), polyurethane (PU) and poly(ethylene terephthalate) (PET), and is universal to other hydrophilic monomers such as 2-hydroxyethyl methacrylate (HEMA), N-aciylamide (NIPAAm) and sulfobetaine methacrylate (SBMA). Protein resistant property of these modified surfaces was comparable to that of the PVC-POEGA surface.