LAUSR

Introduction/Background Ropivacaine, bupivacaine and triamcinolone are used daily in injections during surgeries and pain therapy. The purpose was to analyze the ability of local anesthetics and cortisone to induce apoptosis and necrosis in fibroblasts, tenocytes and human mesenchymal stem cells (hMSC). Material and method Fibroblasts, tenocytes and adipose-derived hMSC were seeded in T25 flasks at a cell density of 0.5 × 104/cm2. Ropivacaine, bupivacaine and triamcinolone were added individually to the cells using concentrations of 0.5%, 0.25% and 0.125%. No addition of specimen was used as negative control. After 30 minutes incubation and medium change the cells were harvested at 1 hour, 24 hours and 7 days of incubation. Analysis via fluorescence-activated cell sorting (FACS) using double-staining with Annexin V and PI was performed. Annexin V stains apoptotic cells while PI enables necrotic cells to be differentiated. Therefore the FACS method allows a quantitative as well as a qualitative analysis of each cell population. SPSS was used for statistical analysis to determine significant difference (P > 0.05) between specimen and control groups. Results Bupivacaine shows necrosis-inducing effects on fibroblasts and tenocytes, the necrotic effect peaking at 0.5%. Ropivacaine and triamcinolone cause no significant necrosis. In comparison to fibroblasts and tenocytes, hMSC did not show significant necrotic or apoptotic effects after exposure to bupivacaine. Overall, no significant difference in apoptosis was detected between different cell lines, varying concentrations of the specimen or time of measurements. Conclusion Bupivacaine 0.5% has the highest necrosis-inducing effect on fibroblasts and tenocytes in comparison to ropivacaine, which causes less necrotic tissue. hMSC exhibited less necrosis compared to fibroblast and tenocytes. This may advise to prefer ropivacaine over bupivacaine for clinical practice.