Effect of surface modification on physical and cellular properties of PCL thin film.

Lack of suitable surface functional groups is one of the main limitations related to the cell attachment of Polycaprolactone (PCL). The aim of this research was to surface modify the PCL film using gelatin coating, via a simple physical entrapment process. In this regard, after preparation of PCL films using casting, they were immersed in each gelatin solutions. Consequently, chemical crosslinking using glutaraldehyde was performed to improve the stability of the PCL-gelatin film. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), Scanning electron microscope (SEM), contact angle measurement, strip tensile test, Dimethylthiazol-diphenyltetrazolium bromide (MTT) assay and Cell seeding were used to evaluate the quality of the coating layer, the thickness of PCL-gelatin film, the surface wettability, their mechanical properties, Cell viability and Cell attachment and proliferation respectively. Results showed that the amount of entrapped gelatin enhanced with increasing acetone in the gelatin solution. Surface modification led to a two-fold increment of mechanical strength, about 50% increase in elastic modulus, 54% in elongation and up to 11% increment in cell viability. Moreover, wettability and cell attachment of PCL film significantly enhanced, after gelatin modification. In conclusion, the simple and cost effective modification of PCL using gelatin entrapment could provide significant mechanical and biological properties making it a promising approach for development of three-dimensional scaffolds for bone tissue engineering.