L-polylactic acid porous microspheres enhance the mechanical properties and in vivo stability of degummed silk/silk fibroin/gelatin scaffold

Abstract

Cartilage defects are among the most difficult diseases to cure in clinic. Due to the limited regeneration capacity of chondrocytes, cartilage regeneration is very difficult. Tissue engineering is a potential strategy for cartilage regeneration. The choice of scaffold is a key factor for the successful construction of tissue engineering cartilage. In this research, we successfully constructed the silk/silk fibroin/gelatin/polylactic acid porous microspheres (S/SF/G/PLLA-PMs) scaffold, then further evaluated the physical and chemical properties and biocompatibility of the composite cartilage tissue in vitro and in vivo, also the long-term survival of the composite cartilage in large animals was carried out. The research results showed that S/SF/G/PLLA-PMs composite scaffold had good biocompatibility. The addition of L-polylactic acid porous microspheres (PLLA-PMs) could significantly enhance the mechanical strength of the scaffold and achieve a multi-level pore structure. After 4 weeks of culture in vitro, composite cartilage could be constructed. Further immunohistochemical results showed that S/SF/G/PLLA-PMs scaffold could increase the long-term stability of the composite cartilage transplantation in vivo.