In vitro and in vivo degradation behavior of aqueous-derived electrospun silk fibroin scaffolds

We investigated the in vitro degradation behavior of the electrospun silk fibroin (SF) scaffolds by protease XIV. Phosphate-buffered saline (PBS) without enzyme was used as a control. About 65% of the electrospun SF scaffolds were degraded within 24 d in protease XIV, while almost no scaffolds were degraded in PBS. A great deal of fragments was visible in protease XIV solution. SEM indicated surface erosion of the scaffolds increased during protease degradation with increasing exposure time. FTIR and XRD indicated the crystalline structure of the scaffolds decreased after protease degradation for 24 d, and a degradation mechanism was proposed. Furthermore, the results of the in vivo degradation by implantation in rats showed that the scaffolds were completely degraded in vivo after implantation for 8 weeks and well tolerated by the host animals. The insights gained in this study can serve as a guide to match desired degradation behavior with specific applications for the electrospun SF scaffolds, such as tissue engineering and drug delivery.