Mussel-inspired Polyglycerol: Synthesis and Versatile Surface Modification

Abstract

The nonspecific binding of undesirable proteins, cells and microorganisms on material surfaces is one of the major problems in the biomedical fields. The nonspecific binding of these biomolecules can initiate blood coagulation, bacterial infection, inflammatory response and accumulation of organisms onto implanted materials, medical devices and underwater constructions. To inhibit these phenomena, antifouling polymers that prevent the nonspecific binding have been used as a solution. Among the various antifouling polymers, polyglycerol (PG), a promising candidate to substitute the traditional poly(ethylene glycol) (PEG), has attracted much attention with its water solubility, biocompatibility and antifouling effect. In addition, the pendent hydroxyl group allows functionalization and various structural forms via a variety of synthetic pathways. However, the immobilization of polymers onto surface requires a robust anchoring mechanism, which can be applied to various substrates. The catechol group, a key element of adhesive property of mussel renders the surface-independent binding ability and a versatile method to modification of material surfaces. In this study, we designed a new acetonide-protected catechol functionalized glycerol monomer (CAG), which was polymerized by anionic ring opening polymerization. A series of catechol functionalized polymer (PCAG) with various molecular weights (6,000 ? 20,000 g/mol) and catechol contents (0 ? 33%) were synthesized in a controlled manner. The acetonide protection was easily removed by acidic treatment and free catechol group was revealed. The immobilization of PCAG on various surfaces would offer the versatile surface modification method. Beyond that, the relationship between antifouling effect and its size, composition and architecture will be covered. We anticipate that this novel catechol functionalized monomer will be used in various applications in biomedical fields.