Synthesis of carboxymethyl chitosan-strontium complex and its therapeutic effects on relieving osteoarthritis.

Osteoarthritis (OA) is an age-related joint disorder and one of the leading causes of physical disability. In this study, we designed and synthesized a new polysaccharide complex, carboxymethyl chitosan strontium (CMCS-Sr), which is believed to have positive effects on relieving OA. The synthesized CMCS-Sr was structurally verified by SEM, EDS, FTIR, etc. The therapeutic effects of CMCS-Sr were evaluated using various biological experiments. The cell viability and apoptosis results reveal that CMCS-Sr can significantly promote the proliferation and suppress OA chondrocytes apoptosis in vitro. The immunofluorescence staining results suggest that CMCS-Sr facilitates the promotion of the secretion of Type II collagen (Col-II). The transcriptomic results support the observed positive effects of CMCS-Sr on inhibiting chondrocytes apoptosis and alleviating inflammatory reactions. Moreover, animal study demonstrates that CMCS-Sr effectively reduced articular cartilage damage and subchondral bone degradation. Therefore, we propose the use of CMCS-Sr as a promising candidate for relieving OA.