Comparison of the Viability of Cryopreserved Fat Tissue in Accordance with the Thawing Temperature

BACKGROUND Adipose tissue damage of cryopreserved fat after autologous fat transfer is inevitable in several processes of re-transplantation. This study aims to compare and analyze the survivability of adipocytes after thawing fat cryopreserved at -20℃ by using thawing methods used in clinics. METHODS The survival rates of adipocytes in the following thawing groups were measured: natural thawing at 25℃ for 15 minutes; natural thawing at 25℃ for 5 minutes, followed by rapid thawing at 37℃ in a water bath for 5 minutes; and rapid thawing at 37℃ for 10 minutes in a water bath. The survival rates of adipocytes were assessed by measuring the volume of the fat layer in the top layers separated after centrifugation, counting the number of live adipocytes after staining with trypan blue, and measuring the activity of mitochondria in the adipocytes. RESULTS In the group with rapid thawing for 10 minutes in a water bath, it was observed that the cell count of live adipocytes and the activity of the adipocyte mitochondria were significantly higher than in the other two groups (P<0.05). The volume of the fat layer separated by centrifugation was also measured to be higher, which was, however, not statistically significant. CONCLUSIONS It was shown that the survival rate of adipocytes was higher when the frozen fat tissue was thawed rapidly at 37℃. It can thus be concluded that if fats thawed with this method are re-transplanted, the survival rate of cryopreserved fats in transplantation will be improved, and thus, the effect of autologous fat transfer will increase.