Fat harvesting protocol for enhanced stem cell viability – pilot study

• Multiple methods exist to extract Adipose-Derived Stem Cells (ASCs) and fat derivatives for medical use. • Saline solution 0.9% was the washing solution that showed the lowest rate of cell death; lidocaine, ropivacaine, and epinephrine caused similar levels of cell death, and passing fat through a 2.4 mm Luer-to-Luer connector up to 20 times did not affect cell viability. • ASC proliferation and differentiation capability into adipocytes, osteocytes, and chondrocytes remained intact with saline and 20 × passages. • These findings may enhance fat graft viability. Adipose tissue is used in several specialties to obtain Adipose-derived Stem Cells (ASC) and fat derivatives. Several studies analyze protocols for harvesting fat tissues. However, these studies showed inconclusive data regarding cell viability and function. Thus, the objective of this study was to analyze protocols regarding cell viability, identify the best method, and test cell differentiation and proliferation when using the chosen methods. This study harvested lipoaspirate products from three healthy women undergoing aesthetic procedures. The first analysis corresponds to the viability of fat tissue liposuction products for the washing process. The second analyzes the effect of anesthetic drugs, and the third analyzes the cytotoxicity of the fraction process. After testing all these steps, the authors prepared the fat tissue using the best method chosen after the first analysis to test cell differentiation (adipogenesis, osteogenesis, and chondrogenesis) and proliferation. The analysis showed that saline solution 0.9% was the washing solution that induced less cell death. Regarding anesthetic and vasoconstrictor drugs, lidocaine, ropivacaine, and epinephrine caused similar levels of cell death, but sodium bicarbonate increased cell proliferation. The number of passages through a 2.4 mm Luer-to-Luer transfer device did not influence cell viability. The proliferation and differentiation of ASC in adipocytes, osteoblasts, and chondrocytes were preserved using saline solution 0.9% and 20 × passages for fat fractioning. The findings of this study provide preliminary in vitro evidence that may improve future investigations on the fat harvesting process.