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.

成熟的脂肪细胞对压力和缺氧敏感，这是大批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。但是，它们的机制仍不清楚。在这项研究中，聚己内酯支架是通过3D打印技术制造的，并与吸脂脂肪复合。将它们皮下植入裸鼠。在不同的时间，进行肉眼和组织学观察以评估保留率和组织学形态。通过特殊的免疫染色分析了脂肪细胞的活力，凋亡和血管形成。定量聚合酶链反应用于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，前者的液泡少，纤维化少。在免疫染色中，到第4周时，在支架组中观察到CD31 +毛细血管升高，更多的脂蛋白+脂肪细胞和更少的TUNEL +凋亡细胞。HIF-1α的较低表达表明缺氧得以缓解。总之，支架提供了抵抗皮肤张力的机械支撑，从而降低了组织间的压力，并改善了物质交换和血管向内生长。在这方面，该支架减轻了缺氧并促进了血管形成，从而使其成为一种可行的方法，以使用具有合适降解率和附加的血管成熟刺激的支架来增加脂肪移植中的长期保留。