Experimental study on the role of intra‐articular injection of MSCs on cartilage regeneration in haemophilia

Summary Mesenchymal stem cells ( MSC s) therapy is a field in progress in cartilage repair strategies. We tried to investigate the functional properties of the joint and cartilage in experimental haemarthrosis ( EH ) after MSC s intra‐articular ( IA ) injection. One millilitre of fresh autologous blood was injected twice a week for three consecutive weeks in three groups including control haemophilia 10 days ( n = 8), control haemophilia 38 days ( n = 8) and MSC s ( n = 8) group. In later, 10 days after the end of IA blood injections, MSC s IA injection was performed. Eight animals received no treatment as the normal control group. Thirty‐eight days after the end of IA blood injections, animals were sacrificed. Joint friction and stress‐relaxation tests were done, inflammatory cytokines of synovial membrane and scanning electron microscopy of the cartilage assessed. Joint friction decreased in MSC s in comparison to other groups and was significant with normal control group, ( P = 0.011). The mechanical properties of cartilage showed no significant differences between groups. Tumour necrosis factor alpha and interleukin 1 beta decreased and IL ‐4 very slightly increased in MSC s in comparison to the time‐matched control group. Scanning electron microscopy enabled acquisition of good structural properties of the surface and layers of the cartilage after MSC s injection. The hole induced in the medial plateau of the tibia bones, after inducing haemarthrosis, were covered with cartilage‐like structure. The results showed that MSC s IA injection has some beneficial effects on cartilage structure and function in haemarthrosis model and is promising in patients with haemophilia.