From the Department of Plastic and Reconstructive Surgery, Dongguk University Medical Center; the Department of Plastic and Reconstructive Surgery, Yeungnam University College of Medicine; the Department of Plastic and Reconstructive Surgery, College of Medicine, Hanyang University; and the Department of Plastic and Reconstructive Surgery, Seoul National University College of Medicine.
Plast Reconstr Surg. 2019 May;143(5):973e-982e. doi: 10.1097/PRS.0000000000005513.
Cell-assisted lipotransfer, a technique involving free fat grafting mixed with adipose-derived stromal cells, has gained popularity for enhancing fat graft retention. In terms of stem cell delivery, intravenous injection can be a novel alternative with clinical value. However, the effects of intravenously injected adipose-derived stromal cells concurrent with fat grafting have not been described. The authors investigated the histologic and microenvironmental changes in grafted fat when adipose-derived stromal cells were injected intravenously concurrent with grafting.
Using a modified animal model of cell-assisted lipotransfer, adipose tissue from green fluorescent protein-expressing C57BL/6J (B6) mice was grafted into recipient wild-type B6 mice, followed by intravenous injection of adipose-derived stromal cells from DsRed-expressing B6 mice. The distribution of adipose-derived stromal cells was evaluated using bioluminescent imaging, and graft volume was measured using micro-computed tomographic scans. Donor fat and adipose-derived stromal cells were traced using immunofluorescent staining.
The authors identified the recruitment of adipose-derived stromal cells inside the graft after intravenous injection of adipose-derived stromal cells concurrent with grafting despite the arrest of cells in the lungs. Intravenous injection of adipose-derived stromal cells resulted in significantly higher adipogenesis gene expression, retention of graft volume, and vascular density of the graft. A tracing study performed until postoperative week 8 revealed that intravenously injected adipose-derived stromal cells mainly induced angiogenesis and adipogenesis by paracrine action rather than direct differentiation.
Consistent with results of cell-assisted lipotransfer, adipose-derived stromal cell supplementation by systemic administration led to improved retention of the fat graft. The findings broaden the surgical options for fat grafting and enhance the clinical value of cell-assisted lipotransfer.
细胞辅助脂肪转移技术是一种涉及游离脂肪移植混合脂肪来源基质细胞的技术，已被广泛应用于提高脂肪移植的保留率。在干细胞递送方面，静脉注射可能是一种具有临床价值的新方法。然而，静脉注射脂肪来源基质细胞与脂肪移植同时进行的效果尚未被描述。作者研究了静脉注射脂肪来源基质细胞与脂肪移植同时进行时，移植脂肪的组织学和微环境变化。
使用改良的细胞辅助脂肪转移动物模型，将绿色荧光蛋白表达的 C57BL/6J（B6）小鼠的脂肪组织移植到野生型 B6 小鼠受体中，然后静脉注射 DsRed 表达的 B6 小鼠的脂肪来源基质细胞。通过生物发光成像评估脂肪来源基质细胞的分布，通过微计算机断层扫描测量移植体积。使用免疫荧光染色追踪供体脂肪和脂肪来源基质细胞。
尽管细胞在肺部被截留，但作者发现，在静脉注射脂肪来源基质细胞与脂肪移植同时进行后，在移植物内招募了脂肪来源基质细胞。静脉注射脂肪来源基质细胞导致移植体的脂肪生成基因表达、移植体积保留和血管密度显著增加。一项持续至术后第 8 周的追踪研究表明，静脉注射的脂肪来源基质细胞主要通过旁分泌作用而不是直接分化来诱导血管生成和脂肪生成。
与细胞辅助脂肪转移的结果一致，系统给予脂肪来源基质细胞补充可改善脂肪移植的保留率。这些发现拓宽了脂肪移植的手术选择，并增强了细胞辅助脂肪转移的临床价值。
