Background: Human-induced pluripotent stem cells (hiPSCs) complement the disadvantages of conventional embryonic stem cells and adult stem cells, and have the advantages of simplicity of production and pluripotency. Some recent studies have applied hiPSC in cell therapy.Methods: In this study, we examined the effect of cells similar to cord blood endothelial colony-forming cells (CB-ECFCs), differentiated from induced pluripotent stem cells, on angiogenesis and granulation tissue formation in the proliferative phase of wound healing. For cell transfer, we used methacrylated gelatin (GelMA)-co-poly(styrene sulfonate) (PSS) cryogel, which has better bioactivity than conventional hydrogels and excellent mechanical properties and swelling capacity. Two full-thickness skin defects, 0.8 cm in diameter, were made in each of our 12 experimental mice. Wound splinting models were used to prevent contraction of the wounds. In each of the experimental animals, 5×10⁵ cells were applied with GelMA-co-PSS cryogel in one of the two wounds, while only a culture medium with cryogel was applied to the other wound.Results: Wound reduction rates in the experimental side showed increases compared to the control side in 3 days, but there was no statistical significance. The histological score was significantly increased (P<0.05), and histologic examination showed that angiogenesis and granulation formation were also increased in the experiment side.Conclusion: In conclusion, CB-ECFCs-like cells differentiated from hiPSCs were effective in promoting formation of angiogenesis and granulation tissue in a mouse wound healing model.

Background and ObjectivesLasers are widely used for scar treatment because they are less invasive and safe. Fractional CO2 laser treatment has proved to be useful for scar treatment but is relatively less effective for depressed or hyperpigmented scars. On the other hand, the picosecond laser, a later development, is known to be more effective for such scars. The purpose of this study was to investigate the effect of combining the two laser treatment methods. Materials and MethodsTwenty-seven patients who received the fractional ablative CO2 laser followed by 1,064-nm Nd:YAG picosecond laser with micro-lens array (MLA) treatments for post-traumatic facial scars were retrospectively evaluated. Photographs were taken before treatment and after the final procedure, and the scars were evaluated using the Vancouver Scar Scale (VSS). ResultsOn average, patients were subjected to 4.37 fractional CO2 laser sessions and 3.67 picosecond laser sessions. The mean of the VSS score improved from 7 to 2. In addition, recovery of the depressed scars was also observed through clinical photo reviews. No complications were reported due to the procedure. ConclusionThe additional application of a picosecond laser with MLA after fractional CO2 laser treatment can be a safe and effective way to further improve outcomes in patients with post-traumatic facial scars including pigmented or depressed scars. Although this study is limited to posttraumatic facial scars, we expect that the results of our study can be extended to scars due to various other causes in the future.

Background: High-intensity focused ultrasound (HIFU) is a widely used procedure for skin rejuvenation because it targets only the superficial musculoaponeurotic system layer with coagulated thermal energy. However, its long procedure time is inconvenient for both the patient and the operator. The purpose of this study was to investigate the clinical effects of 2-line HIFU.Methods: Between August 2021 and September 2022, patients with sagging and loose facial skin were treated with a 2-line HIFU (10thera ® ) following the manufacturer's recommended protocol. We evaluated patients using an automatic skin diagnosis system at the pretreatment stage and about three months after treatment.Results: All patients were treated using the 2-line HIFU. Five patients were lost to follow-up. The median procedure time was 14 minutes. The mean skin grade was 17 at pretreatment and 14 at posttreatment, showing a significant (p < 0.01) difference between the two. Conclusion:This study suggests that the 2-line HIFU can improve wrinkling and sagging of an aging face. It is believed that the shortened treatment time would improve the satisfaction levels of both the operator and the patient.