Mediating specific cell adhesion to low-adhesive diblock copolymers by instant modification with cyclic RGD peptides

Abstract

One promising strategy to control the interactions between biomaterial surfaces and attaching cells involves the covalent grafting of adhesion peptides to polymers on which protein adsorption, which mediates unspecific cell adhesion, is essentially suppressed. This study demonstrates a surface modification concept for the covalent anchoring of RGD peptides to reactive diblock copolymers based on monoamine poly(ethylene glycol)-block-poly(D,L-lactic acid) (H2N-PEG-PLA). Films of both the amine-reactive (ST-NH-PEG2PLA20) and the thiol-reactive derivative (MP-NH-PEG2PLA40) were modified with cyclic αvβ3/αvβ5 integrin subtype specific RGD peptides simply by incubation of the films with buffered solutions of the peptides. Human osteoblasts known to express these integrins were used to determine cell–polymer interactions. The adhesion experiments revealed significantly increased cell numbers and cell spreading on the RGD-modified surfaces mediated by RGD–integrin-interactions.