Synthesis of chondroitin sulfate magnesium for osteoarthritis treatment

•MgCS was prepared by combining magnesium and CS.•MgCS could effectively increase the proliferation and decrease the apoptosis of osteoarthritis (OA) chondrocytes.•RT-qPCR analysis suggested that MgCS could significantly promote collagen formation and have anti-inflammatory effects. Magnesium chondroitin sulfate (MgCS) has been fabricated and characterized in this study. We investigated its morphology, composition as well as structure. The results verify that the sodium of sodium chondroitin sulfate (CS) is successfully replaced by magnesium and formed a polysaccharide-metal ion complex. To evaluate the clinical potential of MgCS, cell proliferation and apoptosis test were conducted. The results reveal that MgCS could effectively increase the proliferation and decrease the apoptosis of osteoarthritis (OA) chondrocytes. Moreover, real-time quantitative polymerase chain reaction (RT-qPCR) was conducted to evaluate the gene expression level. RT-qPCR analysis suggests that MgCS could significantly increase the expression of COLII and decrease the expression of IL-1β and iNOS in OA chondrocytes. Furthermore, significant upregulation of Bcl-2 mRNA expression and downregulation of the expression of apoptosis related gene p53 were observed. Thus, it is indicated that MgCS should have great potentials in OA treatment.