Effect of Gamma Irradiation on the Biocompatibility and Biodegradation of Silk Fibroin <i>In Vivo</i>

Silk fibroin has been a raw material for many artificial biomaterials for a long term, because of it good mechanical property and fantastic biocompatibility. As a natural protein, it has more excellences than other chemically synthetical materials. In present, silk fibroin is used to manufacture bone repair material, artificial blood vessel, microcapsules and so on. However, silk fibroin-based biomaterial is not good enough in biodegradation. In our research, we exposed the silk fibroin film under the gamma ray irradiation with the doses of 25kGy and 50kGy and implanted the film subsequently on the back of SD rats. At dates (7th, 14th, 28th, 56th, 84th ) after implantation, we got the tissue with the implanted film and had the pathological analysis accordingly. The results show that the immune cells infiltration and inflammation decreased within a month. And the immune reaction decreased more quickly in the 50kGy group. And cracks of the silk fibroin film appeared earlier in the 50kGy group. From above observation, it is indicated that the silk fibroin film with a higher dose had better biocompatibility than others. And the silk biodegradation was accelerated by the higher gamma ray dose. Therefore, we can conclude that the gamma ray is able to improve the biocompatibility of silk fibroin and accelerated the biodegradation of it.