Scaffold with Orientated Microtubule Structure Containing Polylysine-Heparin Sodium Nanoparticles for the Controlled Release of TGF-β1 in Cartilage Tissue Engineering

Articular cartilage defects cannot adequately self-repair because of avascular and complex tissues. Although various scaffold materials have been reported to promote cartilage repair, challenges remain in this field. In the present study, an orientated microtubules scaffold that consisted of collagen, chitosan, silk fibroin, and polylysine-heparin sodium nanoparticles containing transforming growth factor β1 (TGF-β1), was constructed using a unidirectional freeze-drying method. The collagen/chitosan/0.5silk fibroin scaffolds showed optimal properties via the evaluation of physicochemical characterization, mechanical properties and biocompatibility. The collagen/chitosan/0.5silk fibroin scaffolds containing polylysine-heparin sodium nanoparticles loaded with TGF-β1 (COL/CS/0.5SF-TPHNs) could control the slow release of TGF-β1. Simultaneously, the in vitro COL/CS/0.5SF-TPHNs scaffolds exhibited not only an excellent biocompatibility to support mouse mesenchymal stem cells (mBMSCs) adhesion and proliferation, but also exhibited excellent repair effect in cartilage defects of rabbit models in vivo. Our results showed that the COL/CS/0.5SF-TPHNs scaffolds have the potential to induce articular cartilage formation, mainly because TGF-β1 could induce the mBMSCs to differentiate into chondrocytes and osteoblasts. Consequently, the current study can achieve cartilage repair, and COL/CS/0.5SF-TPHNs scaffolds are expected to be potential composites for cartilage tissue engineering.