Experimental Study On The Toxicity Of Plasma RF Ablation Products On Normal FLS

Objective:To study the effects of plasma radiofrequency ablation vaporized products on the proliferation and apoptosis of normal FLS and the expression of inflammatory factors,to determine whether the products have cytotoxicity,and to find or exclude possible causes for unexplained synovitis after arthroscopy surgeries,to provide theoretical support for the rational use of plasma radiofrequency ablation systems,and to guide the correct handling of vaporized products during arthroscopic surgery.Methods:(1)Took a New Zealand white rabbit,injected air at the ear vein to make embolism death.Extracted the synovial tissue of the knee joints under aseptic conditions,and collected 20 g of rabbit articular cartilage,meniscus,and synovial tissue,and put in 50 m L isotonic fluid.At room temperature(25℃),simulated surgical operation and ablated knee soft tissue to complete vaporization with plasma radiofrequency,collected plasma radiofrequency ablation products,capped and sealed products solution,stored at room temperature and avoid light.(2)Cultured FLS,did Vimentin identification after success,interfered FLS with products solution at P3,observed and photographed the growth of FLS during culture and the morphological changes after interference.(3)Group: The control group and three experimental groups(high concentration group,middle concentration group,and low concentration group).(4)Measured the cell proliferation rate by CCK-8,after processing with different products solutions,cultured for 4h at normal culture condition with CCK-8 reagent action,measured OD and calculated the cell proliferation rates of every group.Drew cell growth curves.(5)Detected the cell cycle with flow cytometry,and calculated and analyzed the percentage of cells in each phase of G1,S,and G2.(6)Annexin V-FITC/PI double stained FLS,detected FLS apoptosis with flow cytometry.(7)The levels of IL-6 and IL-8 in FLS supernatants were detected by ELISA.Results:(1)Morphological observation showed FLS changed to apoptotic,36 h after interference with products solution.(2)The results of CCK-8 suggested that the proliferation rate of FLS in the experimental group was lower than the control group at 24 h,36h,48 h,and 72 h.Compared at the same detection time,the proliferation rate of the FLS in the experimental group was generally increased as the gas concentration increased,and the proliferation rate decreased.The longer the plasma radiofrequency ablation products treatment time was,the lower the FLS proliferation rate was.Among them,comparison at the 24 h,36h,and 72 h,the difference of proliferation rate among groups was statistically significant,P<0.05.Compared at 48 h between the low concentration group and the middle concentration group,the proliferation rate had no significant difference,P>0.05.(3)Flow cytometry showed that the proportion of cells in the G1 phase increased in the experimental group compared with the control group.Plasma radiofrequency ablation products treatment could block FLS proliferation in the G1 phase,preventing the cell division process.(4)Flow cytometry showed that FLS in experimental group had more apoptosis than control group,and the greater the concentration of plasma radiofrequency ablation products was,the more obvious apoptosis was.(5)The expression of IL-6 and IL-8in the FLS supernatant of the experimental group was significantly higher than control group.Conclusion:Plasma radiofrequency ablation vaporization products have cytotoxicity to normal FLS,inhibit normal FLS proliferation,promote apoptosis,and raise the expression of IL-6and IL-8.