Cell-Adhesive Star Polymers Prepared by ATRP

摘要

This study presents the synthesis and evaluation of cell adhesive polyethylene oxide) (PEO) star polymers for potential biomedical applications. Star polymers with a size of approximately 20 nm and with relatively low polydispersities (M_w/M_n <= 1.6), containing GRGDS (Gly-Arg-Gly-Asp-Ser) segments, were prepared by atom transfer radical copolymerization of PEO methyl ether methacrylate macromonomer (MM), telechelic GRGDS-PEO-acrylate MM, and ethylene glycol dimethacrylate (EGDMA). Results from ~1H NMR spectroscopy confirmed the covalent incorporation of the peptide into the star periphery. In vitro cytotoxicity experiments showed star polymers to be cytocompatible (>95% cell viability) and GRGDS-star hybrid hydrogels supported the attachment of MC3T3.E1 (subclone 4) cells. Hybrid hydrogels were prepared by free radical photopolymerization based on 10% (wt/v) PEO dimefhacrylates M_n = 4000 g/mol with 1% (wt/v) GRGDS-star polymers having different peptide content. Cell adhesiveness was also determined from thin film coatings prepared with GRGDS-containing star polymers on nonadherent plastic plates. After 24 h incubation, phase contrast microscopy and scanning electron microscopy (SEM) images showed uniform cell adhesion and distribution over the film containing cell-adhesive star polymers. These results confirm that incorporation of RGD ligand-binding motifs into PEO-based star polymers is required to influence substrate-cell interactions.