Deer antler reserve mesenchyme cells with hyaluronan alleviates cartilage damage in a rat model

Reserve mesenchyme cells (RMCs) of deer antlers have been considered as the promising cell source for repairing injury-induced articular cartilage or cartilage degeneration. However, systematic investigation of RMC differentiation to repair injured cartilage and its combination with biomaterials has not been reported. The aim of this study was to evaluate the role of RMCs in combination with hyaluronic acid (HA) in promoting chondrogenic differentiation through simulating native environments and their efficacy in articular cartilage repair. The RMCs were cultured in vitro for the characterization of these cells, including morphology, surface marker expression, and multipotent differentiation potential (adipogenesis, chondrogenesis, and osteogenesis). When combined with HA in vitro, RMCs increased expression levels of the chondrogenic marker gene (COL II and COMP) but decreased levels of the hypertrophic marker gene (COL X). Using a rat articular cartilage defect model, we evaluated the effects of RMCs in combination with HA on cartilage defect repair at 4 and 8 weeks through macroscopical, histological, and immunohistochemical examinations. Compared with other groups, treatment with RMCs + HA reduced cartilage loss and degree of cartilage surface worn, whereas cartilage content was significantly increased. These results suggest that the combination of RMCs with HA can effectively repair cartilage defects. We believe that effective cartilage defect repair will benefit from the use of RMCs together with favorable biomaterials, such as HA.