Department of General Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Tissue Engineering, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Department of General Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Mater Sci Eng C Mater Biol Appl. 2021 Apr;123:111973. doi: 10.1016/j.msec.2021.111973. Epub 2021 Feb 16.
Mature adipocytes are sensitive to stress and hypoxia, which are the two major obstacles in large-volume fat grafting. Bionic scaffolds are considered beneficial for fat grafting; however, their mechanism is still unclear. In this study, polycaprolactone scaffolds were fabricated by a 3D-printing technique and compounded with liposuction fat. They were implanted subcutaneously into nude mice. At different times, gross and histological observations were performed to evaluate the retention rates and histological morphologies. Adipocyte viability, apoptosis, and vascularization were analyzed by special immunostaining. Quantitative polymerase chain reaction was used to detect the variations in hypoxia and inflammation. The results showed that the volume and weight retentions in the scaffold group were higher than those in the fat group with the former exhibiting fewer vacuoles and less fibrosis. In immunostaining, elevated CD31+ capillaries, more perilipin+ adipocytes, and fewer TUNEL+ apoptotic cells were observed in the scaffold group by week 4. The lower expression of HIF-1α indicated the alleviation of hypoxia. In conclusion, the scaffold provided mechanical support to resist skin tension, thereby decreasing the interstitial pressure, and improving substance exchange and vascular ingrowth. In this regard, the scaffold attenuated hypoxia and promoted vascularization, making it a feasible method to increase long-term retention in fat grafting using scaffolds with suitable degradation rates and additional vascular maturation stimulation.
成熟脂肪细胞对压力和缺氧敏感，这是大容量脂肪移植的两个主要障碍。仿生支架被认为有利于脂肪移植，但它们的机制尚不清楚。在这项研究中，通过 3D 打印技术制造了聚己内酯支架，并与吸脂脂肪复合。将它们皮下植入裸鼠。在不同时间进行大体和组织学观察，以评估保留率和组织形态学。通过特殊免疫染色分析脂肪细胞活力、细胞凋亡和血管生成。使用定量聚合酶链反应检测缺氧和炎症的变化。结果表明，支架组的体积和重量保留率高于脂肪组，前者的空泡更少，纤维化程度更低。在免疫染色中，第 4 周时支架组的 CD31+毛细血管增多，更多的 perilipin+脂肪细胞和更少的 TUNEL+凋亡细胞。HIF-1α 的表达降低表明缺氧减轻。总之，支架提供了机械支撑来抵抗皮肤张力，从而降低了间质压力，促进了物质交换和血管生成。在这方面，支架通过使用具有适当降解率和额外血管成熟刺激的支架来减轻缺氧并促进血管生成，这是增加脂肪移植中脂肪长期保留的可行方法。
