Antiphotoaging Effect of Micronized Fat in Ultraviolet B–Induced Human Dermal Fibroblasts

Adipose-derived stromal vascular fraction (SVF) and mesenchymal stem cells have been proven to reduce the effects of skin photoaging. However, there is no standardized protocol for their preparation. This study aimed to investigate the skin rejuvenation potential of micronized fat, obtained using a novel device attached with a trifoliate blade, in the ultraviolet B (UV-B)-induced human dermal fibroblast model.Micronized fat was prepared to obtain adipose-derived SVF, and the adipose-derived mesenchymal stem cell-to-SVF ratio was determined by flow cytometry. The UV-B-induced human dermal fibroblasts model was constructed to identify the characteristics of the human dermal fibroblasts using vimentin and S-100 immunostaining, observe their morphology, and measure the levels of photoaging-related factors. After the previous steps were completed, different cell groups were co-cultured with UV-B-induced human dermal fibroblasts, and the extent of improvement of photoaging was evaluated.Micronized fat had a higher adipose-derived mesenchymal stem cell-to-SVF ratio than the control fat preparations. The UV-B-induced human dermal fibroblasts model showed lowered levels of type I collagen and transforming growth factor-β and increased expression of matrix metalloproteinases (MMPs), which are the characteristics of photoaging in normal human dermal fibroblasts. Compared with different cell groups co-cultured with UV-B-induced human dermal fibroblasts, micronized fat could lower the expression of MMPs and increase the level of type I collagen but lower the level of transforming growth factor-β.Obtaining micronized fat is more effortless and clinically safer. Micronized fat has an antiphotoaging effect by inhibiting the expression of MMPs by means of the mitogen-activated protein kinases signaling pathway.The authors' work has potential clinical applications in fat grafting for facial rejuvenation.