Freezing adipose tissue grafts may damage their ability to integrate into the host

In this study, the effect of freezing on the morphology, viability, and VEGF synthesis of human adipose tissue grafts is examined. Currently, storage of adipose grafts involves freezing in simple saline solutions. However, the effect of freezing on the morphology and function of adipose tissue remains unclear. As a result, this study attempts to determine whether freezing adipose grafts should be considered prior to soft-tissue augmentation. In this study, the freezing of adipose grafts in saline for only 24 hr resulted in morphological changes in vivo and affected their ability to synthesize VEGF. The use of a simple cryopreservation medium containing sucrose appeared to maintain VEGF synthetic levels by the grafts and improved both their morphology and retention in vivo. However, the benefits of this cryopreservation medium were directly linked to storage time as long-term storage did not result in any noticeable benefit to graft retention. Finally, as an alternative to freezing, adipose grafts were combined with human adipose-derived stem cells (ASCs) to determine if their presence could enhance in vivo graft structure. The presence of ASCs did appear to improve graft structure in vivo over the short term and was also capable of improving tissue morphology when combined with grafts frozen in PBS. In conclusion, the successful use of adipose grafts may require a closer examination of the graft's storage conditions and time. Specifically, it now appears that the practice of freezing in saline may not be advisable if graft viability, activity, and structure are to be maintained in vivo.