Functionalized hydrogels promote the repair of large segmental bone defects by simultaneously regulating angiogenesis and osteogenesis

The treatment of large segmental bone defects has always been a difficult problem in orthopedic treatment, which is characterized by local microenvironment with impaired blood supply and absolute or relatively insufficient osteogenic ability. In these clinical scenarios, the bone repair process is often hindered, and the incidence of complications is increased. Therefore, obtaining a coordinated microenvironment of angiogenesis and osteogenesis will be an effective treatment strategy. In this study, we incorporated ophiopogon D (OPD) into a hydrogel matrix network with amino polyethylene glycol and sodium alginate oxide as raw materials to construct an injectable functional biomaterial for promoting angiogenesis and osteogenic differentiation. In vitro studies showed that the constructed hydrogel material had satisfactory injectability and self-healing properties, and could continuously release OPD locally, thus promoting the migration and angiogenesis of human umbilical vein endothelial cells in vitro, and promoting the osteogenic differentiation of bone marrow mesenchymal stem cells. After the functional hydrogel was implanted into the large segmental bone defect of the radius in a rabbit model, it could enhance the expression of local angiogenic and osteogenic protein, improve the osteogenic microenvironment, and thus accelerate bone repair. This study provides a new strategy and theoretical basis for the design of minimally invasive bone tissue engineering materials and the treatment of large segmental bone defects.