Collagen-surface modification of ultra thin poly (ε-caprolactone) films

Abstract

Poly (ε-caprolactone) (PCL) has been used as a bioresorbable polymer in numerous medical devices as well as for tissue engineering applications. Its main advantage is its biocompatibility and slow degradation rate. PCL surface, however, is hydrophobic and cell-biomaterial interaction is not the best. We attempt for the first time to modify PCL surface with collagen. The PCL film was prepared using solvent casting and biaxial stretching technique developed in our laboratory. This biaxial stretching produced an ultra thin PCL 3 to 7 μm thick, ideal for membrane tissue engineering applications. The PCL film was pretreated by Argon plasma, and then UV-induced acrylic acid (AAc) polymerization and collagen immobilization were carried out in the surface modification process. The modified film surface was characterized by Fourier Transform Infrared (FT-IR) and X-ray Photoelectron Spectroscopy (XPS). Water contact angles were also measured to valuate the hydrophilism of the modified surface. Results showed that the hydrophilism of the surface has been improved significantly after surface modification. The water contact angle dropped from 66° to 46°. The effect of unmodified PCL film and modified film to cell growth also was studied. Dermal fibroblasts growth was improved remarkably on the modified surface than unmodified one. PCL-Col films showed excellent cell attachment and proliferation rate.