Intra-articular injection of human umbilical cord-derived mesenchymal stem cells in sheep models of meniscectomy-induced osteoarthritis: An experimental study

INTRODUCTION: Autologous mesenchymal stem cells (MSC) implantation suspended in hyaluronic acid (HA) has been proven to delay worsening of articular cartilage degeneration in the knee joint. This has been the treatment of choice for young patients with knee osteoarthritis (KOA); however, it is associated with morbidities such as requirement of multiple procedures, donor site morbidity and failure in achieving cultured cells with chondrogenic properties. Our study investigates the possibility of direct intra articular injection of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) for sheep models of meniscectomy-induced osteoarthritis. METHODS: Twelve sheeps with the same characteristics was osteoarthritically induced with lateral meniscectomy and a series of routine exercise. Those sheep were divided into four groups with 3 sheep each. The groups are the control group, intra articular HA (hyalgan G-F 20; Synvisc®) injection group, intra articular hUC-MSCs group, intra articular hUC-MSCs suspended in HA group. The sheeps were sacrificed four weeks post-treatment for gross pathology and histopathology graded according to the Osteoarthritic Research Society International (OARSI) system. RESULTS: The intra articular hUC-MSCs suspended in HA group showed better gross pathology and histopathology grade compared to control groups (p<0.05) according to the OARSI system. The hUC-MSCs suspended in HA group microscopically showed superior chondrocyte number and varying degrees of cellular regeneration of articular cartilage. CONCLUSION: The use of intra articular hUC-MSCs suspended in HA is an option in treating KOA. Its efficacy in articular cartilage regeneration would be further explained in clinical trials.