Fat Graft Retention: Adipose Tissue, Adipose-Derived Stem Cells, and Aging | Journal CME Article-Fat Graft Retention: Adipose Tissue, Adipose-Derived Stem Cells, and Aging

Fat Graft Retention: Adipose Tissue, Adipose-Derived Stem Cells, and Aging | Journal CME Article

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This comprehensive review discusses the critical role of adipose tissue (AT) and adipose-derived stem/stromal cells (ASCs) in fat grafting and tissue regeneration, with particular focus on how aging impacts graft survival and regenerative potential. AT is widely used as a filler for soft-tissue correction due to its abundance and regenerative qualities, largely attributed to ASCs which have multipotent differentiation capability and secrete growth factors promoting angiogenesis, immunomodulation, and extracellular matrix (ECM) remodeling.<br /><br />Age-related changes in AT include volume loss, reduced preadipocyte proliferation, decreased vascularity, impaired angiogenic capacity, and increased fibrosis. These alterations compromise fat graft retention and skin regeneration. ASCs can modulate local immune responses by promoting a shift from pro-inflammatory M1 to anti-inflammatory M2 macrophages, which supports tissue repair and angiogenesis. They also influence ECM remodeling by enhancing collagen organization and regulating matrix metalloproteinases, reducing fibrosis.<br /><br />In fat grafting, graft survival depends not only on ASCs but also on graft particle size, oxygen diffusion, vascularization, and matching the embryonic origin of donor and recipient fat to optimize outcomes. Larger fat parcels risk central necrosis due to insufficient oxygenation, while too much injection causes ischemia from increased interstitial pressure. ASCs augment graft retention by enhancing vascularization through differentiation into endothelial cells and secretion of angiogenic factors like VEGF and b-FGF.<br /><br />Aging negatively affects ASC function, including reduced differentiation, proliferation, and secretion of pro-angiogenic factors. However, literature is conflicting regarding the extent of age effect on ASC yield and potential. Additional factors influencing fat graft survival include donor and recipient age, sex, body mass index, inflammatory status, harvesting techniques, and anatomical fat depot origin.<br /><br />Overall, while ASCs are pivotal in fat graft survival and skin regeneration, aging impairs their regenerative abilities and the complex interaction between ASCs, macrophage polarization, and angiogenesis requires further research. This knowledge is vital for optimizing fat grafting procedures and developing therapies to improve graft retention and regenerative outcomes in aging populations.

Keywords

adipose tissue

adipose-derived stem cells

fat grafting

tissue regeneration

aging effects

angiogenesis

macrophage polarization

extracellular matrix remodeling

graft survival

stem cell differentiation