Type-I Collagen Polypeptide-Based Composite Nanofiber Membranes for Fast and Efficient Bone Regeneration

The clinical treatment of bone defects includes allogeneic bone transplantation and autologous bone transplantation. However, they all have their own limitations, and the scope of application is limited. In recent years, bone tissue engineering scaffolds based on a variety of materials have been well developed and achieved good bone regeneration ability. However, most scaffold materials always face problems such as high biotoxicity, leading to inflammation and poor bioactivity, which limits the bone regeneration effect and prolongs the bone regeneration time. In our work, we prepared hydroxyapatite, erythropoietin (EPO), and osteogenic growth peptide (OGP) codoped type-I collagen (Col I) polypeptide nanofiber membranes (NFMs) by electrostatic spinning. In cell experiments, the composite NFMs had low cytotoxicity and promoted osteogenic differentiation of rat bone marrow mesenchymal stem cells. Quantitative real-time polymerase chain reaction and alkaline phosphatase staining confirmed the high expression of osteogenic genes, and alizarin red S staining directly confirmed the appearance of calcium nodules. In animal experiments, the loaded hydroxyapatite formed multiple independent mineralization centers in the defect center. Under the promotion of Col I, EPO, and OGP, the bone continued to grow along the mineralization centers as well as inward the defect edge, and the bone defect completely regenerated in about two months. The hematological and histological analyses proved the safety of the experiments. This kind of design to promote bone regeneration by simulating bone composition, introducing mineralization center and signal molecules, can shorten repair time, improve repair effect, and has good practical prospects in the future.