Abstract:Objective To observe the effect of adipose-derived stem cells (ADSCs) on pain and cartilage renovation in knee osteoarthritis (KOA). Methods The ADSCs with different concentration (1×106 /ml, 1×107 /ml, 1×108 /ml) were obtained from fats in SD rats, and the pain models of KOA in rats were established by iodoacetic acid method. 40 SD rats were selected and were randomly divided into blank group, KOA model group, ADSCs low-concentration group, ADSCs middle-concentration group and ADSCs high-concentration group, 8 cases in each group. The rats in ADSCs low-concentration group, ADSCs middle-concentration group and ADSCs high-concentration group were administrated with intra-articular injection of low-concentration ADSCs, middle-concentration ADSCs and high concentration ADSCs in bilateral knee joint, once a week for consecutive 4 weeks. Pressure-pain threshold, Paw withdrawal latency (PWL) and Mankin's scoring of knee joint were performed regularly, and pathological results were observed after 4 injections. Results At the 2nd and 4th week after the model replication, the results of the tenderness experiment showed that the comparison results of the tenderness thresholds of the five groups were as follows: there were differences in the tenderness thresholds at different time points (P?0.05); there was no difference in the tenderness thresholds among the five groups (P?>?0.05); there were differences in the change trend of the tenderness thresholds among the five groups (P?0.05). Meanwhile, the results of the hot pain experiment showed that the hot pain thresholds of the five groups were different at different time points (P?0.05); there was no difference in hot pain thresholds among the five groups (P?>?0.05); there was no difference in the change trend of the hot pain thresholds among the five groups (P?>?0.05). Compared with the blank group, the pathological results showed that the KOA model group had the defect of articular cartilage surface, the loss of chondrocytes, proteoglycan degradation, fibrosis and degeneration of subchondral bone; low, medium and high concentration ADSCs had the improvement effect on the articular cartilage. Among them, cartilage surface defect, chondrocyte deletion and hypertrophic phenotype were still found in the low concentration ADSCs treatment group; chondrocytes survived in the middle concentration ADSCs treatment group, but there were still surface defects and cell hypertrophic degeneration; cartilage in the high concentration ADSCs treatment group basically returned to normal, cartilage surface thickened, and only a small number of hypertrophic chondrocytes were found. The Mankin's score of KOA model group was higher than that of blank group, ADSCs low concentration treatment group, ADSCs medium concentration treatment group and ADSCs high concentration treatment group (P?0.05). Conclusion ADSCs can ameliorate joint pain in KOA rats and repair cartilage damage, suggesting this technique can be used for adjuvant treatment of clinical KOA.