Effect of Co-transplanting Stromal Vascular Fraction-Gelatin and Platelet-Rich Fibrin on the Long-Term Maintenance of Fat Volume.

objectiveIn the present study, we aimed to investigate the survival of stromal vascular fraction-gelatin (SVF-gel) grafts and determine whether co-transplantation of SVF-gel and platelet-rich fibrin (PRF) improves long-term maintenance of fat volume (Wei et al. in Oncotarget 8:68542-68556, 2017) in a rabbit model.

methodsSVF-gel was transplanted into the ears of 12 rabbits with (experimental group) or without PRF (control group). Transplantation retention was evaluated based on weight, histology, and immunohistochemistry.

resultsIn the 2nd and 4th weeks, the volume of fat was larger in the experimental group than in the control group. In the 6th week, the absorption of fat was noticeable in both groups, and there was no significant difference in the fat survival rate between the two groups (experimental group: 1.051 ± 0.144 and control group: 0.789 ± 0.232, P > 0.05). HE staining results: At week 2, adipocytes were observed in the experimental group and tended to mature over time. These adipocytes also exhibited an ordered arrangement. Adipocytes with abnormal morphology appeared in the control group in the 4th week. At different weeks, there were more inflammatory cells and fibroblasts in the experimental group than in the control group, and they were arranged in an ordered fashion. Immunohistochemical results: More brown areas were observed in the experimental group than in the control group, and the morphology and distribution of adipocytes in the experimental group were better than those in the control group. The distribution of fibrocytes was also more regular in the experimental group than in the control group.

conclusionSVF-gel cannot maintain long-term filling in rabbit ears. The addition of PRF has no influence, although PRF can induce SVF-gel to transform into adipocytes, and the anti-inflammatory effect is noticeable in the early period following the procedure. Co-transplantation also helped to ensure orderly arrangement of fibrin. There were no "volume preservation differences in this experimental model" perhaps there are differences if other models/methodology are employed. No Level Assigned 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 Table of Contents or online Instructions to Authors - www.springer.com/00266 .