Cryopreservation of lipoaspirates: in vitro measurement of the viability of adipose-derived stem cell and lipid peroxidation

As the storage time of the fat tissue passes by, lipid peroxidation and creation of by-products may take place. The objective of this study was to evaluate the cell viability and functional changes of adipose-derived stem cells (ADSCs) in the cryopreserved lipoaspirates at different temperatures in accordance with lipid peroxidation. Lipoaspirates acquired from liposuction were divided into four different temperature groups and stored at 4 degrees C, -20 degrees C, -80 degrees C, and -196 degrees C. After isolating ADSC from each sample, gross cell morphology and cell viability were compared with doubling time and colony-forming unit (CFU) formation ability. Acid value, that is, thiobarbituric acid value was measured to assess lipid peroxidation. No viable ADSC was observed in -20 degrees C and -196 degrees C samples for past 1 week and a superior number of the live cells were detected in the 4 degrees C group compared with the -80 degrees C group. However, the persistence of cell division and CFU formation after 1 week was only observed in adipocytes stored at -80 degrees C. Lipid peroxidation mainly occurred at 4 degrees C and -20 degrees C storage samples. If the lipoaspirates were planned to be cryopreserved, it is advised to store at -80 degrees C. However, the number of actually functional ADSCs is very low. Furthermore, even in the cryopreserved status, continuous lipid peroxidation and by-product creation took place, suggesting shorter preservation period as possible in the clinics.