Surface functionalization of polycaprolactone films via surface-initiated atom transfer radical polymerization for covalently coupling cell-adhesive biomolecules.

The ability to manipulate and control the surface properties, without altering the substrate properties, is of crucial importance in the designing of biomedical materials. In this work, surface-initiated atom transfer radical polymerization (ATRP) is employed to tailor the functionality of polycaprolactone (PCL) film surfaces in a well-controlled manner. Functional polymer brushes of glycidyl methacrylate (GMA) were prepared via surface-initiated ATRPs from the PCL film surfaces. Kinetics study revealed that the chain growth from the PCL films was consistent with a controlled process. The dense and reactive epoxide groups of the grafted P(GMA) brushes were used for the direct coupling of cell-adhesive collagen and Arg-Gly-Asp-Ser (RGDS) peptides to improve the cell-adhesion properties of the PCL film surface. These modified surfaces were evaluated by culturing of a cell line, 3T3 fibroblasts. The cell attachment and proliferation were improved remarkably on the collagen (or RGDS) functionalized PCL film surfaces. The adhesion results also indicated that the collagen-coupled PCL film surface is better for the cell-adhesion process. With the versatility of surface-initiated ATRP and the good biocompatibility nature of biomolecules, the PCL films with desirable surface functionalities can be precisely tailored to cater to various biomedical applications. Copyright 2010 Elsevier Ltd. All rights reserved.