The gold standard cell therapy for repair of articular cartilage defects is autologous chondrocyte implantation, with good outcomes long-term. Mesenchymal stromal/stem cells (MSCs) from bone marrow or connective tissues such as fat are being pursued as alternatives for cartilage repair, and are trialled via intra-articular administration in patients with knee osteoarthritis. Early-phase clinical studies concur on safety and provide some promising insight into efficacy, but the mechanism of action remains unclear. Recent studies implicate extracellular vesicles as important mediators of MSC action, offering exciting therapeutic prospects. Our increasing understanding of the mechanisms underlying intrinsic articular cartilage maintenance and repair fosters hope that novel/repurposed therapeutics could elicit repair through activation of endogenous stem/progenitor cells to maintain healthy joints and prevent osteoarthritis
Bibliographical noteWe are grateful to Medical Illustration at the University of Aberdeen for drawing the schematic in Figure 1, and to Arthritis Research UK (grants 19667, 20050, 20775, 20865, 21156) and the Medical Research Council (grants MR/L020211/1, MR/L022893/1) for supporting our work.
- Cell therapy
- Mesenchymal stem cell