A single integrated osteochondral in situ composite scaffold with a multi-layered functional structure

This work focuses on the optimization design of a functional biomimetic scaffold for the repair of osteochondral defects and includes the study of single integrated osteochondral tissue engineering scaffolds with a multi-layered functional structure. Rabbit model experiments were used to evaluate the repair of osteochondral defects. The results revealed that good integration was achieved both at the interfaces between the scaffold material and the host tissue and between the newly formed subchondral bone and cartilage. The highest total histological score of 24.2 (based on the modified O'Driscoll scoring system at 12 weeks post-operation) was achieved for osteochondral repair. The completely repaired cylindrical full-thickness defects for the rabbit animal model reached 5 mm in diameter. The thickness of the regenerated cartilage was almost in line with that of the surrounding normal cartilage, the number and arrangement of cells in the superficial area of cartilage were very close to those of normal hyaline cartilage, and there were clear cartilage lacunas in the regenerated cartilage. The hybrid-use of growth factors and LIPUS stimulation exhibited good potential in enhancing vascularization and the formation of new bone and cartilage, providing better conditions for the overall osteochondral repair.