Surface Modification of Polyhydroxyalkanoates by Ion Implantation. Characterization and Cytocompatibility Improvement

Surface modification of three species of PHAs, PHB, P(HB-co-HV) and P(HB-co-HH), were carried out by 40 keV C+ ion implantations at four different doses, 1 × 1012, 1 × 1013, 1 × 1014, and 1 × 1015 ions cm-2. Remarkable changes between the pristine samples and the implanted samples were observed for the FT-IR and XPS spectra. Fibroblast culture was conducted to investigate the surface biocompatibility changes caused by the implantation of C+. From the results of the MTT colorimetric test and the cell morphology observation assessed by SEM, FI and Confocal Laser Scanning Microscopy (CLSM), there were several evidence that the cytocompatibility of the films were improved by ion implantation and the best cytocompatibility was achieved at the ion dose of 1 × 1012 for all the three species of PHAs. Possible explanation is given by correlating the cell adhesion figures with the chemical and physical changes in the modified surfaces. Results show that the PHAs modified by ion implanting could be a promising family of biomaterials for tissue engineering.