BACKGROUND:Cell-free therapy is a research hotspot in the field of medical cosmetic anti-aging.It is still unknown for paracellular secretion of human umbilical cord mesenchymal stem cell-derived small extracellular vesicles loaded with the antiaging drug α-ketoglutaric acid to delay skin aging.OBJECTIVE:To investigate the effect of the anti-aging agent α-ketoglutarate engineered human umbilical cord mesenchymal stem cell-derived small extracellular vesicles in a D-galactose-induced model of dermal fibroblast senescence.METHODS:(1)Biological characteristics of primary human umbilical cord mesenchymal stem cells were identified by osteogenic-lipogenic differentiation staining and flow cytometry.(2)The small extracellular vesicles derived from human umbilical cord mesenchymal stem cell were obtained by using differential-ultracentrifugation.α-Ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles were constructed by electroporation,and biologically characterized by transmission electron microscopy and nanoparticle tracking analyzer,while the encapsulation rate was assessed using high-performance liquid chromatography.(3)The effect of α-ketoglutarate on the proliferative capacity of dermal fibroblasts was assessed by CCK-8 and Edu cell proliferation assay kits.(4)The effect of α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles on delaying the senescence of dermal fibroblasts was evaluated by reactive oxygen species detection kit,western blot assay,and cellular immunofluorescence.RESULTS AND CONCLUSION:(1)The obtained human umbilical cord mesenchymal stem cell and human umbilical cord mesenchymal stem cell-small extracellular vesicles were biologically compatible.(2)There was no toxic effect on dermal fibroblasts when α-ketoglutarate was used in the concentration range of 0.5-8 mmol/L.(3)D-gal induced senescence in dermal fibroblasts,while α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles treatment reduced the level of oxidative stress,DNA damage,and collagen loss,which was further verified that α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles could effectively slow down the skin aging process.

BACKGROUND:Cell-free therapy is a research hotspot in the field of medical cosmetic anti-aging.It is still unknown for paracellular secretion of human umbilical cord mesenchymal stem cell-derived small extracellular vesicles loaded with the antiaging drug α-ketoglutaric acid to delay skin aging.OBJECTIVE:To investigate the effect of the anti-aging agent α-ketoglutarate engineered human umbilical cord mesenchymal stem cell-derived small extracellular vesicles in a D-galactose-induced model of dermal fibroblast senescence.METHODS:(1)Biological characteristics of primary human umbilical cord mesenchymal stem cells were identified by osteogenic-lipogenic differentiation staining and flow cytometry.(2)The small extracellular vesicles derived from human umbilical cord mesenchymal stem cell were obtained by using differential-ultracentrifugation.α-Ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles were constructed by electroporation,and biologically characterized by transmission electron microscopy and nanoparticle tracking analyzer,while the encapsulation rate was assessed using high-performance liquid chromatography.(3)The effect of α-ketoglutarate on the proliferative capacity of dermal fibroblasts was assessed by CCK-8 and Edu cell proliferation assay kits.(4)The effect of α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles on delaying the senescence of dermal fibroblasts was evaluated by reactive oxygen species detection kit,western blot assay,and cellular immunofluorescence.RESULTS AND CONCLUSION:(1)The obtained human umbilical cord mesenchymal stem cell and human umbilical cord mesenchymal stem cell-small extracellular vesicles were biologically compatible.(2)There was no toxic effect on dermal fibroblasts when α-ketoglutarate was used in the concentration range of 0.5-8 mmol/L.(3)D-gal induced senescence in dermal fibroblasts,while α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles treatment reduced the level of oxidative stress,DNA damage,and collagen loss,which was further verified that α-ketoglutarate-engineered human umbilical cord mesenchymal stem cell-small extracellular vesicles could effectively slow down the skin aging process.