3D printing of biomimetic hierarchical porous architecture scaffold with dual osteoinduction and osteoconduction biofunctions for large size bone defect repair

Large size bone defects typically need a long recovery period of more than three months, while a rapid repair of large bone defects is of great important and presents a significant challenge in clinical. Osteoinduction and osteoconduction provide different pathways and biofunctions for bone repair. Here, a biomimetic bone spatial architecture scaffold loaded with drug were constructed for satisfied both of these two bone repair biofunctions. Contacted with the host bone tissue, the HAp scaffold facilitates osteoconduction mainly through the outer layer of the scaffold. Meanwhile, GelMA loaded drugs primarily facilitates osteoinduction in the inner layer of the scaffold by establishing an osteogenic microenvironment. In vitro cell experiments confirmed that HAp/GelMA/ IC showed excellent biocompatibility and osteogenic differentiation. An animal model of rabbit femoral condyle defect confirmed that HAp/GelMA/IC promoted osteoinduction and osteoconduction biofunctions. This dual biofunctions design provided a promising strategy for fast bone reconstruction in the large size bone defects repair.