Synthesis of end group-functionalized PGMA-peptide brush platforms for specific cell attachment by interface-mediated dissociative electron transfer reversible addition-fragmentation chain transfer radical (DET-RAFT) polymerization

Abstract

Polymer brush synthesis is a powerful approach to fabricate functional bio-interfaces. To enhance the control over brush synthesis and end groups, we have synthesized poly(glycidyl methacrylate) PGMA brushes with carboxylic acid end functional groups by interface-mediated dissociative electron transfer reversible addition-fragmentation chain transfer radical (DET-RAFT) polymerization on titanium surfaces. This method does not require the use of metals and occurs under mild conditions. The brushes obtained were analyzed comprehensively in order to understand how to control cell attachment behavior. The PGMA brushes synthesized by DET-RAFT polymerization were characterized by X-ray photoelectron spectroscopy (XPS), grazing angle Fourier transform infrared (GA-FTIR) spectroscopy, water contact angle measurements and variable angle spectroscopic ellipsometry. The terminal carboxylic acid functional groups were covalently conjugated with arginine-glycine-aspartic acid (RGD) and arginine-alanine-aspartic acid (RAD, negative control) peptides in one step. RGD selective attachment of NIH 3T3 fibroblasts was observed exclusively on PGMA-RGD brushes. Thus, a new versatile strategy has been validated to obtain functional biointerfaces for selective cell attachment in the absence of any metallic catalyst.