Decellularized xenogenic cartilage extracellular matrix (ECM) scaffolds for the reconstruction of osteochondral defects in rabbits

The usage of decellularized native allogenic or xenogenic cartilaginous extracellular matrix (ECM) is widely expanding in the field of tissue engineering and regenerative medicine. Herein, we aimed to develop an acellular, affordable, biodegradable easily available goat chonchal cartilaginous ECM derived scaffolding biomaterial in repair and regeneration of osteochondral defects in rabbits. The freshly collected cartilages were decellularized separately using chemical agents, namely, Hypotonic-Hypertonic (HH) buffers and Triton X- 100 solution. The morphology and ultra structure orientation of the decellularized cartilages remained unaltered in spite of complete cellular loss. Furthermore, when the acellular cartilaginous ECMs were cultured with murine mesenchymal stem cells (MSCs) (C3H10T1/2 cells), cellular infiltration, proliferation were thoroughly monitored by SEM, DAPI and FDA stained images whereas, the MTT assay proved biocompatibility of the matrices. The increasing amount of secreted ECM proteins (collagen and sGAG) depicted successful chondrogenic differentiation of the MSCs in presence of the treated cartilage samples. In vivo biocompatibility study showed no significant immune response or tissue rejection in treated samples whereas, with tissue necrosis in control samples after 3 months. Upon implantation in rabbits’ osteochondral defects for 3 months, the histological and micro-CT evaluation revealed significant enhancement and regeneration of neocartilage and subchondral bony tissues. The IGF-1 loaded cartilaginous constructs showed comparatively better healing response after 3 months. Our results showed that decellularized xenogenic cartilaginous biomaterials preserved the bioactivity and integrity of the matrices that also favored the in vitro stem cell proliferation, chondrogenic differentiation and enabled osteochondral regeneration, thus paves a new insight for articular cartilage reconstruction.