PGRN-Loaded Silk Fibroin/Chitosan/Polydopamine Scaffolds For Bone Repair

The objective of our research is to develop a natural bone repair material that exhibits superior biocompatibility and osteogenic activity. In this study, silk fibroin/chitosan composite scaffolds were fabricated using the freeze-drying method. Leveraging the strong adhesive properties of polydopamine coatings, PGRN protein was immobilized on the surface of the scaffolds to construct a composite material. The biocompatibility, biodegradability, and mechanical properties of the scaffolds were systematically evaluated. The sustained-release effect of PGRN was further confirmed through Enzyme-Linked Immunosorbent Assay (ELISA). Ultimately, the scaffold group with the optimal biocompatibility and physicochemical properties was selected for co-culture with bone marrow mesenchymal stem cells (BMSCs) to assess osteogenic potential, and its efficacy was validated in a rat calvarial defect model. The physicochemical and biocompatibility tests demonstrated that the scaffold possesses excellent biocompatibility, biodegradability, and mechanical properties..The ELISA experiments indicated that the material has a sustained-release effect on PGRN. In vitro experiments showed that compared with the unloaded group, the SF/CS-PDA-PGRN scaffold significantly promoted the proliferation of BMSC cells and upregulated the expression of osteogenesis-related genes. The rat cranial defect model further verified that this material can accelerate new bone formation. The results demonstrate that the SF/CS-PDA-PGRN scaffold achieves efficient loading of PGRN through the adhesive properties of PDA (polydopamine), and synergistically enhances osteogenic performance. This scaffold holds potential for application in bone tissue engineering and provides a novel strategy for the development of biomaterials for bone defect repair.