Figure 1.

uMSC-Exos suppress myofibroblast aggregation and scar formation in a full-thickness skin defect mouse model. (A): Upper: Images of indicated cell-transplanted wound at 14th day after initial treatment. Lower: Scar formation of mice in different treatment groups at 25 days after transplantation. (B): Quantification of wound diameter (upper) and the scar length (lower) of different treatment groups indicated in (A). ∗∗, p < .01. (C): Representative images of immunohistochemistry showing α-SMA expression in the indicated treatment groups. Scale bar = 500 μm. (D): Representative image of purified exosome particles (left) and the particle size distribution in purified uMSC-Exos (right) as determined by NanoSight. The red arrow indicates exoxomes. Scale bar = 1 μm. (E): Precise particle size distribution of purified uMSC-Exos determined by laser light scattering assessment. The dashed dot line indicates the peak particle size of purified uMSC-Exos. (F): Western blot analysis identifying purified uMSC-Exos using CD81 and CD63 antibody. (G): Representative immunohistochemistry showing α-SMA expression in the indicated exosome-treated groups. Phosphate-buffered saline used as control. Scale bar = 500 μm. Abbreviations: Medium, umbilical cord-derived mesenchymal stem cell culture medium; Mock, phosphate-buffered saline group; N, normal region; SMA, α-smooth muscle actin; UEFS, umbilical cord-derived mesenchymal stem cell exosome-free supernatant; uMSC-Exos, umbilical cord-derived mesenchymal stem cell-derived exosomes; W, wound region.