Fractional carbon dioxide laser-induced photothermal activation of mesenchymal stem cell-derived exosomes accelerates diabetic wound healing by enhancing angiogenesis

Figure 3 Characterization of exosomes. A: Transmission electron microscopy images showing the morphology of exosomes (Exos) and CO₂ laser-Exos. Scale bar = 100 nm; B: Western blot analysis of exosomal markers CD63 and tumor susceptibility gene 101 in Exos and CO₂ laser-Exos; C: Nanoparticle tracking analysis of size distribution of Exos and CO₂ laser-Exos; D: Confocal laser scanning microscopy showing the uptake of PKH26-labeled Exos and CO₂ laser-Exos by human umbilical vein endothelial cells. Exos and nuclei were stained red and blue, respectively. Scale bar = 10 μm. Exos: Exosomes; CO₂ laser-Exos: Exosomes derived from CO₂ laser-preconditioned adipose-derived mesenchymal stem cells; TSG101: Tumor susceptibility gene 101.