脂肪颗粒组织在不同低温条件下冻存后活力分析及移植成活率测定

Viability and post-transplantation survival rate of adipose tissue cryopreserved at different conditions

目的探讨脂肪颗粒组织冻存后的活力及移植成活率。方法在-16℃、-80℃及-196℃条件下，经相应的低温保护剂处理，冻存脂肪颗粒组织，分别于2、4、8周复温后研磨，测定其活力与移植成活率，于移植后7周切取移植物，测量其体积，行苏丹3染色。结果-196℃组及-80℃组较好保持了脂肪细胞活力，冻存8周后活力分别达冻存前的70％和60％，各时间点比较差异无统计学意义（P=0．964，P=0．199）；而-16℃组冻存2周后活力已不到50％，各时间点比较差异有统计学意义（P=0．001），随时间延长表现为进行性下降趋势。-196℃组及-80℃组移植成活率与新鲜脂肪移植成活率相比差异无统计学意义，-16℃组移植成活率与新鲜脂肪移植成活率比较差异有统计学意义（P=0．000）；-16℃组移植物以炎性反应为主，几乎无成活脂肪细胞，其余各组均可见大量成活脂肪细胞。结论-196℃及-80℃条件下短期内（8周）冻存脂肪颗粒具有可行性，适用于临床移植需求。-16℃条件下冻存的脂肪颗粒活力明显降低，移植后虽可维持一定体积，但有可能仅起到一种软组织填充物的作用，在此温度下冻存的脂肪颗粒应用于临床注射无可行性。

Objective To study the viability and post-transplantation survival rate of frozen adipose tissue. Method Treated with the appropriate cryoprotectors, fat granules was cryopreserved at -16℃, -80℃ and -196℃ respectively. Thawing at 2, 4 and 8 weeks, the activity and post-transplantation survival rate of frozen fat was determined. Results After 8 weeks frozen storage, compared with that of fresh fat, the viability of adipose tissue was kept well at -196℃ and -80℃ group, which reached to 70% and 60% respectively. Statistical difference was not significant at each time point. However, at - 16℃ group, the viability of adipose tissue was inferior to 50 % after 2 weeks. The obvious statistical difference appeared （P=0. 001） at each time point and showed downtrend with time. There was no statistical difference between fresh fat （control group） and frozen fat （-196℃ and -80℃ group） in post-transplantation survival rate. But statistical difference was significant between -16℃ group and control group （P=0. 000）. The significant histological findings in -16℃ group were inflammatory change, and few adipocytes were observed. In contrast, a large number of adipocytes were found in other groups. Conclusions Short-term frozen storage of adipose tissue at the temperature of -196℃ and -80℃ is suitable for the clinical repeated fat injection. The viability of adipose tissue is obviously declined while stored at -16℃. This frozen fat could maintain definite volume after injection, but may be served only as a soft-tissue filling material. It should be not recommended in preserving adipose tissue at this temperature for later injection.