A silk fibroin scaffold that accelerates both biodegradation and cell proliferation by incorporating sericin

When 3D silk fibroin scaffolds are used for the regeneration of soft tissues with fast regeneration rates, such as skin dermis, one concern is to accelerate the biodegradation of scaffolds and to match the degradation rate of scaffolds with the regeneration rate of tissues. In this study, sericin was incorporated into 3D silk fibroin scaffolds through crosslinking and followed by freeze-drying. The effects of incorporating sericin on the pore wall microstructure within the scaffolds, the biodegradability of scaffolds and cell proliferation within scaffolds were investigated. It was found that a large number of secondary pores and nanoscale particles were generated on the pore walls within the scaffolds due to the incorporation of sericin and that the number of secondary pores and the size of the particles increased with increasing sericin proportion. The results of in vitro biodegradation and coculture with human umbilical vein vascular endothelial cells demonstrated that the incorporation of sericin not only significantly accelerated the degradation of 3D silk fibroin scaffolds, but also promoted cell adhesion and proliferation. The secondary pores and particles generated on the pore walls inside the fibroin/sericin hybrid scaffolds had a positive contribution to promoting cell adhesion and proliferation. This study provides a biocompatible method for the modification of silk fibroin scaffolds, which can not only accelerate the biodegradation of the scaffold but also promote the adhesion and proliferation of seeded cells.