Cell Toxicity in Fibroblasts, Tenocytes, and Human Mesenchymal Stem Cells-A Comparison of Necrosis and Apoptosis-Inducing Ability in Ropivacaine, Bupivacaine, and Triamcinolone.

PURPOSE

To analyze the ability of ropivacaine, bupivacaine, and triamcinolone to induce apoptosis and necrosis in fibroblasts, tenocytes, and human mesenchymal stem cells.

METHODS

Human dermal fibroblasts, adipose-derived human mesenchymal stem cells (hMSCs), and tenocytes gained from the rotator cuff tendon were seeded with a cell density of 0.5 × 10/cm. One specimen of ropivacaine, bupivacaine, and triamcinolone was tested separately on the cells with separate concentrations of 0.5%, 0.25%, and 0.125% for each specimen. The negative control received no agent, only a change of medium. The incubation period for each agent was 30 minutes. After a change of medium and 1 hour, 24 hours, and 7 days of incubation, 10 cells were harvested and analyzed via fluorescence-activated cell sorting with double-staining with annexin V and propidium iodide. Statistical analysis to determine significant difference (P < .05) between the groups with SPSS statistics 23 through one-way analysis of variance with a univariate general linear model was performed.

RESULTS

Bupivacaine showed necrosis-inducing effects on fibroblasts and tenocytes, with the necrotic effect peaking at 0.5% and 0.25%. Ropivacaine and triamcinolone caused no significant necrosis. Compared with fibroblasts and tenocytes, hMSCs did not show significant necrotic or apoptotic effects after exposure to bupivacaine. Overall, no significant differences in apoptosis were detected between different cell lines, varying concentrations, or time measurements.

CONCLUSIONS

Bupivacaine 0.5% and 0.25% have the most necrosis-inducing effects on fibroblasts and tenocytes. Ropivacaine caused less necrosis than bupivaine. Compared with fibroblasts and tenocytes, hMSCs were not affected by necrosis using any of the tested agents. A significant apoptosis-inducing effect could not be detected for the different cell lines.

CLINICAL RELEVANCE

Possible cell toxicity raises questions of concern for intra-articular injections using local anesthetics and corticosteroids. The present study demonstrates the necrotic and apoptotic effects of ropivacaine, bupivacaine, and triamcinolone and may give recommendations for intra-articular use of local anesthetics and corticosteroids.