Assesment of monocyte phagocytosis in the presence of synovial-fluid-derived exosomes from osteoarthritis patients

Osteoarthritis (OA) is a degenerative joint disease characterised by cartilage degradation, inflammation, and joint dysfunction, and monocytes play an important role in its pathogenesis via phagocytosis and inflammatory regulation. This study investigated the effect of synovial fluid-derived exosomes from OA patients on monocyte phagocytic activity. Synovial fluid (SF) was harvested from OA patients undergoing total knee arthroplasty, and exosomes were isolated by ultracentrifugation. Monocytes from healthy donor were cultured for 24 and 48 hours at different exosome concentrations (1:10, 1:20, and 1:40). Then, pHrodo™ Green E. coli conjugates were used to measure monocyte phagocytosis, which was quantified by flow cytometry. The findings demonstrated a significant increase in monocyte phagocytic activity upon exosome treatment, indicating a modulatory effect. These findings provide insight into the interaction between exosomes and monocyte in OA pathogenesis, underlining the possibility of exosome-based treatments to manage this degenerative illness