Local anesthetics have a major impact on viability of preadipocytes and their differentiation into adipocytes.

Background: Autologous fat transplantation is a well-established technique in surgery. Moreover, the use of preadipocytes in soft-tissue engineering is currently being intensely investigated. Current efforts focus on identifying maneuvers that may minimize resorption and provide predictable late results. The aim of this study was to investigate the influence of different local anesthetics frequently used in clinical practice on the viability of preadipocytes and their ability to differentiate into adipocytes.

Methods: Human preadipocytes were isolated from subcutaneous adipose tissue of 15 patients and treated with bupivacaine, mepivacaine, ropivacaine, articaine/epinephrine, and lidocaine for 30 minutes. Viability was determined directly after treatment and during the ensuing cultivation. Differentiation of preadipocytes was determined by expression of the adipocyte marker adiponectin.

Results: Although the immediate effects of mepivacaine and ropivacaine were only moderate, treatment with articaine/epinephrine and lidocaine strongly impaired preadipocyte viability. Cells normally attached to the culture dishes and proliferated irrespective of the previous treatment. During long-term cultivation, articaine/epinephrine-treated cell viability decreased markedly, whereas other local anesthetics had no impact. Despite normal phenotypic appearance of cells treated with bupivacaine, mepivacaine, ropivacaine, and lidocaine, all local anesthetics markedly impaired adipocyte differentiation as determined by adiponectin expression.

Conclusions: The authors' results show that there is a marked influence of local anesthetics not only on the quantity but also on the quality of viable preadipocytes as determined by their ability to differentiate into mature adipocytes. Therefore, these results should be considered in the context of autologous fat transfer and soft-tissue engineering.