Comparison of Bone Marrow Mesenchymal Stem Cells-Derived Exosomes, Microvesicles, and Soluble Proteins on Their Chondroprotective Effects and Therapeutic Efficacy of Osteoarthritis Treatment

As a disabling joint disorder, osteoarthritis (OA) is characterized by the degeneration of articular cartilage. Bone marrow mesenchymal stem cells (BMSCs) is considered and used as a tool that is regulated by paracrine for the treatment of OA. Herein, we explored the potential of exosomes (Exos), microvesicles (MVs), and soluble proteins (SPs) produced and isolated from rat BMSCs. First, we observed the biological effects of Exos, MVs, and SPs on IL-1β treated rat chondrocytes. Then, we intra-articularly injected Exos, MVs, SPs, and BMSCs in anterior cruciate ligament transection (ACLT)-induced rat OA model, and observed their therapeutic efficacy. SPs rather than Exos and MVs isolated from rat BMSCs exerted a chondroprotective effect in vitro; MVs and SPs showed comparable effects to the intra-articular injection of BMSCs, whereas the chondroprotective effects of Exos were less potent in vivo. In conclusion, the BMSCs secretome might have inconsistent effects in vivo with in vitro, and Exos might not be superior than other secretome in posttraumatic OA prevention.