Effects of exosomes secreted by induced pluripotent stem cells on keratinocyte proliferation and migration
Objective To explore the role of exosomes secreted by induced pluripotent stem cells(iPSC)in promoting the proliferation,invasion and migration of keratinocytes,thereby facilitating wound healing.Methods Extract iPSC-Exos and identify them through transmission electron microscopy,nanoparticle tracking analysis technology,and Western blotting.Purified iPSC-Exos labeled with PKH26 were added to keratinocytes(HaCaT)for the determination of keratinocyte uptake of exosomes.The optimal working concentration of exosomes was assessed using cell counting kit-8(CCK-8),and cells were divided into control group(cell scratch),and experimental group(cell scratch followed by addition of exosomes at the optimal working concentration).Proliferation,migration,and invasion abilities of cells in each group were evaluated using CCK-8,5-ethynyl-2'-deoxyuridine(EdU),scratch assay,and Transwell assay.Results iPSC-Exos exhibit a membranous vesicular structure with a round or elliptical shape,and their diameter is(120.00±25.00)nm.The expression of characteristic surface markers CD9,CD63,and CD81 on iPSC-Exos is positive in the experimental group,while being negative in the control group.HaCaT cells are capable of internalizing iPSC-Exos.After 24 hours of intervention,the scratch healing rates in the control and experimental groups are(25.70±1.07)%and(71.60±12.76)%,respectively.The Transwell invasion cell numbers are(86.33±10.79)and(166.33±24.13)in the control and experimental groups,and the EdU-positive proportions are(45.30±3.17)%and(78.10±6.29)%,respectively.The above indicators in the experimental group show statistically significant differences compared to the control group(all P<0.05).Conclusion The exosomes secreted by pluripotent stem cells can promote the proliferation,migration,and invasion of keratinocytes,thereby indirectly promoting wound healing.