The fate of cryopreserved adipose aspirates after in vivo transplantation

Background: Successful long-term preservation of adipose tissues may have an important impact on future clinical application of autologous fat transplantation. Our group has recently developed an optimal cryopreservation method for possible long-term preservation of adipose aspirates. Objective: The purpose of this study was to evaluate the fate of previously cryopreserved adipose aspirates after in vivo administration in an established nude mouse model. Methods: Adipose aspirates were collected from a cosmetic lipoplasty of the patient's abdomen after centrifugation. In the fresh control group (n = 20), fresh adipose aspirates were injected into the posterior scalp of a nude mouse. In the optimal cryopreservation group (n = 20), adipose aspirates after the optimal cryopreservation were injected. In the simple cryopreservation group (n = 20), adipose aspirates after the simple cryopreservation were injected. All animals in each group were observed for gross appearance of maintained fat grafts over their posterior scalps for up to 16 weeks. The final volume and weight of maintained fat grafts and their histology were evaluated at the end of the study. Results: More maintained volume, weight, and fatty tissue structure of injected free grafts were found in the optimal cryopreservation group compared with the simple cryopreservation group, but the results were still less satisfactory than those in the fresh control group. Conclusions: Based on this in vivo study, we believe that an optimal cryopreservation method developed in our laboratory provides reasonably good long-term preservation of adipose aspirates. However, further studies may still be warranted to refine our method for optimal cryopreservation of adipose tissues.