Evaluation of cell affinity on poly(L-lactide) and poly(e-caprolactone) blends (PLLA/PCL) and on PLLA-b-PCL diblock copolymer surfaces

An evaluation of cell proliferation and adhesion on biocompatible film supports was performed. A series of films were compression molded from commercially available poly (L-lactide), PLLA, and poly(e-caprolactone), PCL, and from their melt mixed blends (PLLA/PCL blends). These were compared with compression molded films of PLLA-b-PCL model diblock copolymers. The samples were analyzed by differential scanning calorimetry (DSC), contact angle measurements, and scanning force microscopy (SFM). Cell adhesion and proliferation were performed with monkey derived fibroblasts (VERO) and with osteoblastic cells obtained either enzymatically or from explants cultures of Sprague-Dawley rat calvaria. Migration studies were performed with bone explants of the same origin. The results obtained indicate that although all materials tested were suitable for the support of cellular growth, a PLLA-b-PCL diblock copolymer sample with 93% PLLA was significantly more efficient. This sample exhibited a unique surface morphology with long range ordered domains (of the order of 2-3 µm) of edge-on PLLA lamellae that can promote 'cell contact guidance.' The influence of other factors such as chemical composition, degree of crystallinity, and surface roughness did not play a major role in determining cell preference toward a specific surface for the materials employed in this work.