Mechanically-reinforced 3D scaffold constructed by silk nonwoven fabric and silk fibroin sponge

Silk fibroin (SF) has made major contribution to the development of a rich variety of tissue-engineered scaffolds, mainly owing to its low cost, good biocompatibility, and proper biodegradability. However, scaffold of pure SF shows poor performance in terms of the mechanical strength, especially when they are constructed to a three-dimensional (3D), porous structure for bulk tissue regeneration. Herein, we report the fabrication of a typical class of 3D porous sponges made of SF, which are mechanically reinforced by integrating with a silk nonwoven fabric. It was found that the silk fibers in the fabric were closely bonded with SF inside the matrix sponge post freeze-drying, which significantly increased the compressive and tensile stress relative to the case of pure SF sponge. We then took fibroblasts (L929) as a model cell to investigate the 3D cell growth inside the scaffold. The cell viability, proliferation, and infiltration were noticeably improved when the silk nonwoven fabric was integrated into the SF sponge. Taken together, this class of mechanical-reinforced, 3D composite scaffolds hold great potential in the regeneration of bulk tissues and related applications.