Comb copolymers for regulating cell-surface interactions

Abstract

Synthetic comb copolymers which elicit controlled cellular response, methods of applying these polymers to various surfaces, and methods of using the polymers for modifying biomaterial surfaces, in tissue engineering applications and as drug delivery devices are provided. The comb copolymers are comprised of hydrophobic polymer backbones and hydrophilic, non-cell binding side chains which can be end-capped with cell-signaling ligands that guide cellular response. By mixing non-cell binding combs with ligand-bearing combs, the surface concentration and spatial distribution of one or more types of ligands, including adhesion peptides and growth factors, can be tuned on a surface to achieve desired cellular response. In one embodiment, the combs are used as stabilizing agents for dispersion polymerization of latexes. The comb-stabilized latexes can be applied to substrates by standard coating operations to create a bioregulating surface, or used as drug delivery agents. In another embodiment, the combs can be blended in small quantities to a hydrophobic matrix polymer and processed to affect the surface segregation of the comb. The comb copolymers are formed in one embodiment by providing a biodegradable polyester backbone that includes reactive groups, and reacting the reactive groups in the backbone with reactive chain ends on a low molecular weight hydrophilic polymer. In another embodiment, non-biodegradable comb copolymers are formed by free radical synthesis of a hydrophobic monomer and a hydrophilic macromonomer. In all of the above embodiments, a portion of the hydrophilic polymer side chains can be covalently coupled to cell-signaling ligands such as adhesion peptides or growth factors to control cellular response.