Viability of Fat Cells in Frozen Fat Tissue in Relation to Thawing Technique

Damage of frozen fat, which will be used for retransplantation, is inevitable. Reuse of frozen fat requires a thawing process. No standardized method has yet been established for thawing frozen fat. METHODS: Microscopic analysis of count and viability of frozen fat of 21 patients. Two fat samples from each patient were harvested and frozen at –20°C in a common commercial refrigerator for different freezing durations. Thawing of fat samples was done. There was one (3 mL) sample for each thawing technique; technique A included natural thawing at 25°C for 15 minutes, while rapid thawing at 37°C for 10 minutes in a water bath was included in technique B. Survival rates of adipocytes were assessed with trypan blue staining. Culturing of adipose-derived stem cells to assess their ability to divide was done. Relating survival rate of frozen fat to patients’ age and to duration of freezing was done. Results were statistically analyzed. RESULTS: The count of viable adipocytes is higher in technique A. Adipose-derived stem cells of frozen fat do not have the ability to divide in culture media. Viable adipocytes were higher in younger ages and in shorter freezing duration. CONCLUSION: Natural thawing is better in maintaining frozen adipocyte viability. Younger patients will benefit from frozen fat more than older ones. Duration of freezing should not exceed 7 months.