Abstract: Keloids and hypertrophic scars are diseases specific to human skin that occur due to delayed inflammatory responses during the wound healing process, activating fibroblasts which produce excessive collagen. This process is often triggered by mechanical stress or infection. Current non-invasive treatments include the application of steroid impregnated tapes or local injection of steroids to suppress inflammation. However, steroids have adverse effects that cannot be ignored. In addition, since the maximum dosage is determined, the range of treatment in one session is limited for extensive scars. We have previously demonstrated and reported that human adipose-derived stem cell concentrated conditioned medium (ADSC-CM) suppress the expression of inflammation-related genes and collagen production genes in fibroblasts and further suppress the contractile ability of collagen disks by fibroblasts. In this study, we have conducted experiments to observe the effects of ADSC-CM on hypertrophic scar tissue in vivo by using a nude mouse model transplanted with human keloid tissue. Collagen gene expression was compared by qPCR to evaluate the effects of ADSC-CM. Immunohistochemical staining was performed to evaluate the activation of fibroblasts. ADSC-CM treated scar tissue showed tendency of collagen gene expression downregulation. The therapeutic potential of ADSC-CM in the treatment of keloids and hypertrophic scars may be promising.
