Extracellular matrix derived from allogenic decellularized bone marrow mesenchymal stem cell sheets for the reconstruction of osteochondral defects in rabbits.

Bioactive scaffolds from synthetical polymers or decellularized cartilage matrices have been widely used in osteochondral regeneration. However, the risks of potential immunological reactions and the inevitable donor morbidity of these scaffolds have limited their practical applications. To address these issues, a biological extracellular matrix (ECM) scaffold derived from allogenic decellularized bone marrow mesenchymal stem cell (BMSC) sheets was established for osteochondral reconstruction. BMSCs were induced to form cell sheets. Three different concentrations of sodium dodecyl sulfate (SDS), namely, 0.5%, 1%, and 3%, were used to decellularize these BMSC sheets to prepare the ECM. Histological and microstructural observations were performed in vitro and then the ECM scaffolds were implanted into osteochondral defects in rabbits to evaluate the repair effect in vivo. Treatment with 0.5% SDS not only efficiently removed BMSCs but also successfully preserved the original structure and bioactive components of the ECM When compared with the 1% and 3% SDS groups, histological observations substantiated the superior repair effect of osteochondral defects, including the simultaneous regeneration of well-vascularized subchondral bone and avascular articular cartilage integrated with native tissues in the 0.5% SDS group. Moreover, RT-PCR indicated that ECM scaffolds could promote the osteogenic differentiation potential of BMSCs under osteogenic conditions while increasing the chondrogenic differentiation potential of BMSCs under chondrogenic conditions. Allogenic BMSC sheets decellularized with 0.5% SDS treatment increased the recruitment of BMSCs and significantly improved the regeneration of osteochondral defects in rabbits, thus providing a prospective approach for both articular cartilage and subchondral bone reconstruction with cell-free transplantation.