Functionalized Decalcified Bone Matrix Scaffold for Cartilage and Bone Regeneration and Repair of Osteochondral Composite Defects

Decellularized Wharton's jelly (DWJ) and decalcified bone matrix (DBM) are naturally derived biomaterials that serve as ideal scaffolds for repairing articular defects. DWJ secretes various bioactive factors that promote cartilage regeneration. However, it lacks sufficient mechanical strength to provide adequate support. DBM has an appropriate mechanical strength and osteogenic inductivity. However, its excessively large pore size results in low cell adhesion rates. To address these challenges, in this study, a functionalized decalcified bone matrix (FDBM) scaffold is fabricated by loading DWJ mixed with gelatin (GT) onto DBM, which is followed by freeze-drying and cross-linking. In vitro, the FDBM demonstrates the ability to induce bone marrow mesenchymal stem cells (BMSCs) to differentiate into chondrocytes and regenerate high-quality cartilage-like tissues within the cartilage microenvironment. In vivo, the cartilage tissue, regenerated from the BMSCs loaded onto FDBM, exhibited a robust endochondral ossification effect in the non-cartilage environments. Furthermore, FDBM offers chondrogenic and osteogenic microenvironments similar to natural joint tissue and has successfully repaired articular osteochondral defects in a rabbit model of osteochondral composite defects. This functional composite scaffold offers a new strategy for the clinical treatment of osteochondral composite defects.