Limido Ettore, Weinzierl Andrea, Ampofo Emmanuel, Harder Yves, Menger Michael D, Laschke Matthias W
Institute for Clinical and Experimental Surgery, Saarland University, Homburg, Germany.
Department of Plastic Surgery and Hand Surgery, University Hospital Zurich, Zurich, Switzerland.
Front Bioeng Biotechnol. 2024 Jul 1;12:1427232. doi: 10.3389/fbioe.2024.1427232. eCollection 2024.
Nanofat is an autologous fat derivative with high regenerative activity, which is usually administered immediately after its generation by mechanical emulsification of adipose tissue. For its potential repeated use over longer time, we herein tested whether cryopreservation of nanofat is feasible. For this purpose, the inguinal fat pads of donor mice were processed to nanofat, which was i) frozen and stored in a freezer at -20°C, ii) shock frozen in liquid nitrogen with subsequent storage at -80°C or iii) gradually frozen and stored at -80°C. After 7 days, the cryopreserved nanofat samples were thawed and immunohistochemically compared with freshly generated nanofat (control). Nanofat frozen and stored at -20°C exhibited the lowest apoptotic rate and highest densities of blood and lymph vessels, which were comparable to those of control. Accordingly, nanofat cryopreserved at -20°C or control nanofat were subsequently fixed with platelet-rich plasma in full-thickness skin defects within dorsal skinfold chambers of recipient mice to assess vascularization, formation of granulation tissue and wound closure by means of stereomicroscopy, intravital fluorescence microscopy, histology and immunohistochemistry over 14 days. These analyses revealed no marked differences between the healing capacity of wounds filled with cryopreserved or control nanofat. Therefore, it can be concluded that cryopreservation of nanofat is simply feasible without affecting its viability and regenerative potential. This may broaden the range of future nanofat applications, which would particularly benefit from repeated administration of this autologous biological product.
纳米脂肪是一种具有高再生活性的自体脂肪衍生物，通常在通过机械乳化脂肪组织产生后立即进行施用。鉴于其可能在较长时间内重复使用，我们在此测试了纳米脂肪的冷冻保存是否可行。为此，将供体小鼠的腹股沟脂肪垫加工成纳米脂肪，其被：i）冷冻并储存在-20°C的冰箱中；ii）在液氮中速冻，随后储存在-80°C；或iii）逐步冷冻并储存在-80°C。7天后，将冷冻保存的纳米脂肪样本解冻，并与新鲜生成的纳米脂肪（对照）进行免疫组织化学比较。在-20°C冷冻保存的纳米脂肪表现出最低的凋亡率以及最高的血管和淋巴管密度，这与对照相当。因此，将在-20°C冷冻保存的纳米脂肪或对照纳米脂肪随后与富含血小板的血浆一起固定在受体小鼠背部皮褶腔的全层皮肤缺损中，通过立体显微镜、活体荧光显微镜、组织学和免疫组织化学在14天内评估血管生成、肉芽组织形成和伤口闭合情况。这些分析显示，填充有冷冻保存的纳米脂肪或对照纳米脂肪的伤口在愈合能力方面没有明显差异。因此，可以得出结论，纳米脂肪的冷冻保存简单可行，且不会影响其活力和再生潜力。这可能会拓宽未来纳米脂肪的应用范围，重复施用这种自体生物产品将使其特别受益。
