Department of Plastic Surgery, Xuzhou Medical University Affiliated Hospital, Xuzhou, China.
Xuzhou Medical University, Xuzhou, China.
Aesthetic Plast Surg. 2019 Jun;43(3):826-835. doi: 10.1007/s00266-019-01314-8. Epub 2019 Feb 15.
Nowadays, the use of cryopreserved fat tissue for soft tissue augmentation is common, except for its unpredictable fat graft absorption, and the toxicity of the cryoprotective agent remains a limitation. In this study, the effects of freezing stored fat tissue without a cryoprotector, and the addition of the stromal vascular fraction (SVF) on the survival of cryopreserved transplants was studied.
Lipoaspirates from six donors were processed and cryopreserved at - 20 °C, - 80 °C and - 196 °C, respectively. The authors evaluated the lipoaspirates in vitro, on the basis of fat tissue and SVF viability after cryopreservation. In vivo fat grafting was performed in nude mice. Six trenches were injected on the backs of mice. Cryopreserved tissues (- 20 °C, - 80 °C and - 196 °C) were injected on the right side, and the other side received the SVF combination. At 4 and 8 weeks after transplantation, the authors examined the weight, volume and morphology of the tissue and analyzed histochemical staining and immunohistochemistry (i.e., DIL, CD31 and VWF) to evaluate the survival of the fat grafts.
After cryopreservation without the cryoprotective agent, adipose tissue maintained its morphology better in - 80 °C than - 20 °C and - 196 °C. SVF cells can retain their adhesive and proliferative properties after cryopreservation. Although cryopreservation caused damage to fat tissue, all explants showed intact adipocytes and vascular ingrowth. Most of all, the - 80 °C group had less graft resorption and fibrosis than the other temperature groups. There was increased survival of fat grafts in the SVF group compared with the control group.
In this study, the authors demonstrated that the storage temperature of - 80 °C was promising for 3 months of adipose tissue cryopreservation without a cryoprotective agent, and SVF could increase the survival rate of cryopreserved fat tissue.
This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
目前，人们常使用冷冻保存的脂肪组织进行软组织填充，除了脂肪移植物吸收率不可预测外，冷冻保护剂的毒性仍然是一个限制因素。本研究旨在研究不添加冷冻保护剂冷冻储存脂肪组织以及添加基质血管成分（SVF）对冷冻移植存活率的影响。
分别从 6 名供体中提取脂肪抽吸物，在-20°C、-80°C 和-196°C 下进行处理和冷冻保存。作者根据冷冻保存后脂肪组织和 SVF 的存活率对脂肪抽吸物进行了体外评估。将冷冻保存的脂肪组织和 SVF 混合物注射到裸鼠背部的 6 个沟槽中，在右侧注射冷冻保存的组织（-20°C、-80°C 和-196°C），另一侧注射 SVF 混合物。在移植后 4 周和 8 周，作者检查了组织的重量、体积和形态，并分析了组织化学染色和免疫组织化学（即 DIL、CD31 和 VWF），以评估脂肪移植物的存活率。
在不使用冷冻保护剂的情况下进行冷冻保存后，与-20°C 和-196°C 相比，-80°C 下脂肪组织的形态保持更好。SVF 细胞在冷冻保存后仍能保持其黏附和增殖特性。尽管冷冻保存会对脂肪组织造成损伤，但所有的样本都显示出完整的脂肪细胞和血管生长。最重要的是，-80°C 组的移植物吸收率和纤维化程度均低于其他温度组。SVF 组的脂肪移植物存活率高于对照组。
在这项研究中，作者证明了在不使用冷冻保护剂的情况下，-80°C 的储存温度有望实现 3 个月的脂肪组织冷冻保存，并且 SVF 可以提高冷冻保存脂肪组织的存活率。
本杂志要求作者为每篇文章分配一个证据级别。有关这些循证医学评级的完整描述，请参阅目录或在线作者指南 www.springer.com/00266 。
