Double-Layered Collagen/Silk Fibroin Composite Scaffold That Incorporates TGF-β1 Nanoparticles for Cartilage Tissue Engineering

A double-layered collagen/silk fibroin composite scaffold that incorporates TGF-/beta 1/poly-L-lysine nanoparticles was prepared in this study. The microstructure and morphology of the obtained scaffold were examined through transmission electron microscopy and scanning electron microscopy. Scaffold exhibited a double-layered structure with TGF-beta 1-loaded poly-L-lysine-heparin (PLL-Hep) nanoparticles sandwiched between dense and loose layers. TGF-beta 1 release displayed a spatiotemporal control model. In vitro biocompatibility and fluorescence staining test with Bone Marrow Stromal Cells revealed that scaffold could significantly enhance cell proliferation. The prepared scaffold was then implanted into full-thickness articular cartilage defects in rabbits. The results indicated that the group exhibiting loose layer facing the surface of subchondral bone was repaired more effectively than displayed a loose layer facing the opposite direction. Therefore, this composite is expected to be a potential scaffold for cartilage tissue engineering material.