Fig. 1
Construction and characterization of genetically and optogenetically engineered UCMSCs and UCMSCs-exo/eNOS. a Flow cytometry analysis of cell surface markers on UCMSCs. The isotype control is illustrated as an orange curve and the test samples are illustrated as solid blue curves. b Tri-lineage differentiation assay of UCMSCs. UCMSCs were able to differentiate into adipocytes, chondrocytes, or osteoblasts when cultured in lipogenic, chondrogenic, or osteogenic media as indicated by Alizarin Red S staining (scale bar: 400 μm), Oil Red O staining (scale bar: 400 μm), and Alcian Blue staining (scale bar: 400 μm). c Imaging of UCMSCs expressing two recombinant proteins, CIBN-EGFP-CD9 and eNOS-mCherry-CRY2, before and after laser stimulation at 488 nm. Scale bar: 20 μm. d Size distribution of UCMSCs-exo/eNOS obtained using dynamic light scattering. The average width of the UCMSCs-exo/eNOS was 78.82 nm. e Morphology of USC-Exos observed by transmission electron microscopy. Scale bar: 200 nm. f UCMSCs expressing CIBN-EGFP-CD9 and eNOS-mCherry-CRY2 were cultured under blue light irradiation at different powers for 48 h. The isolated exosomes were analyzed by immunoblotting with an antibody against CRY2. g Lysis and immunoblot analysis of UCMSCs and UCMSCseNOS-secreted exosomes. h Confocal microscopy analysis showing DiI-labeled UCMSCs-exo/eNOS incorporated into human vascular endothelial cells (HUVECs). Scale bar: 20 μm. All experiments were repeated three times independently