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Autologous fat transplantation is increasingly applied in plastic and reconstructive surgery. Stromal vascular fraction cells (SVFs) combined with angiogenic factors, such as VEGF (vascular endothelial growth factor A) and Ang‐1 (angiogenin‐1), can improve angiogenesis, which is a critical factor for graft survival. However, direct transplant with such a mixture is insufficient owing to the short half‐life of angiogenic factors. In this study, we evaluated whether a double sustained release system of VEGF/ANG‐1‐PLGA (poly (lactic‐co‐glycolic acid)) microspheres plus SVFs can improve angiogenesis and graft survival after autologous fat transplantation. VEGF/ANG‐1‐PLGA‐sustained release microspheres were fabricated by a modified double emulsion–solvent evaporation technique. Human aspirated fat was mixed with SVF suspension plus VEGF/ANG‐1 sustained release microspheres (Group C), SVF suspension (Group B) alone, or Dulbecco's modified Eagle's medium as the control (Group A). Eighteen immunocompromised nude mice were injected with these three mixtures subcutaneously at random positions. After 8 weeks, the mean volume of grafts was greater in the SVFs plus VEGF/ANG‐1‐PLGA group than in the control and SVFs groups (1.08 ± 0.069 ml vs. 0.62 ± 0.036 ml, and 0.83 ± 0.059 ml, respectively). Histological assessments showed that lower fibrosis, but greater microvascular density in the SVFs plus VEGF/ANG‐1‐PLGA group than in the other groups, though the SVFs group also had an appropriate capillary density and reduced fibrosis. Our findings indicate that SVFs plus VEGF/ANG‐1‐PLGA‐sustained release microspheres can improve angiogenesis and graft survival after autologous fat transplantation. Our study demonstrates that stromal vascular fraction cells combined with dual sustained release VEGF/ANG‐1‐PLGA microspheres can improve angiogenesis and graft survival. Nude mice treated with stromal vascular fraction cells and the microspheres developed in this study exhibited reduced fibrosis and increased microvascular density. These findings provide a practical method for improving graft survival after autologous fat transplantation. [ABSTRACT FROM AUTHOR]

Background: Adipose-derived stem cells have attracted significant interest, especially in stem cell therapy and regenerative medicine. However, these cells undergo gradual premature senescence in long-term cultures, which are essential for clinical applications that require cell-assisted lipotransfer or tissue repair. Methods: Since the extracellular matrix forms the microenvironment around stem cells in vitro and regulates self-renewal and multipotency in part by slowing down stem cell aging, we evaluated its potential to protect against senescence, using H 2 O 2 -induced adipose-derived stem cells as a model. Results: We found that supplementing cultures with decellularized extracellular matrix harvested from the same cells significantly promotes proliferation and reverses signs of senescence, including decreased multipotency, increased expression of senescence-associated β-galactosidase, and accumulation of reactive oxygen species. Conclusion: These findings suggest a novel approach in which an autologous decellularized extracellular matrix is used to prevent cellular senescence to enable the use of adipose-derived stem cells in regenerative medicine., (© 2019 The Author(s).)

Objective: To review the research progress of growth factor sustained-release microspheres in fat transplantation., Methods: The recently published 1iterature at home and abroad related the growth factor sustained-release microspheres in fat transplantation was reviewed and analyzed., Results: The sustained-release microsphere carrier materials include natural polymer materials and synthetic polymer materials.The sustained-release complexes of different microsphere materials with different growth factors can promote the vascularization of transplanted fat in a timely manner, improve the survival rate of grafts, and reduce the incidence of complications such as liquefaction, calcification, and necrosis., Conclusion: The growth factor sustained-release microspheres have the characteristics of persistence and controllability, which is a research hotspot in the field of fat transplantation and has broad application prospects.