Fabrication and characterization of a novel silk fibroin film with UV and thermal resistance

Abstract

Silk fibroin is an excellent material for use in tissue engineering owing to its biocompatibility and biodegradability. For proper sterilization, it is necessary to investigate the properties of the material after irradiation with ultraviolet rays prior to implementation. In this study, grinded silk fibroin (GF) films with an ultraviolet (UV)-resistant property using a grinding method without the application of an organic solvent have been successfully prepared. A regenerated silk fibroin (RF) film using a conventional method was also prepared as a comparative sample. The Fourier transform infrared spectroscopy (FT-IR) and atomic force microscope (AFM) results show that the surface of the RF film was photo-oxidized with UV-C light irradiation and that the fibroin molecular chains were decomposed. Furthermore, the modulus of the RF film decreased. However, almost no oxidation deterioration or shape change of the film surface occurred when UV-C light was irradiated on the developed GF film, indicating that the thermal-decomposition temperature and mechanical properties maintained their initial values. These results strongly suggest that GF films prepared using the novel approach have superior thermal and mechanical properties compared with RF films prepared through a conventional method. In addition, GF films achieve a superior UV-C resistance property.