Exosomes derived from human adipose mensenchymal stem cells accelerates cutaneous wound healing via optimizing the characteristics of fibroblasts

Prolonged healing and scar formation are two major challenges in the treatment of soft tissue trauma. Adipose mesenchymal stem cells (ASCs) play an important role in tissue regeneration, and recent studies have suggested that exosomes secreted by stem cells may contribute to paracrine signaling. In this study, we investigated the roles of ASCs-derived exosomes (ASCs-Exos) in cutaneous wound healing. We found that ASCs-Exos could be taken up and internalized by fibroblasts to stimulate cell migration, proliferation and collagen synthesis in a dose-dependent manner, with increased genes expression of N-cadherin, cyclin-1, PCNA and collagen I, III. In vivo tracing experiments demonstrated that ASCs-Exos can be recruited to soft tissue wound area in a mouse skin incision model and significantly accelerated cutaneous wound healing. Histological analysis showed increased collagen I and III production by systemic administration of exosomes in the early stage of wound healing, while in the late stage, exosomes might inhibit collagen expression to reduce scar formation. Collectively, our findings indicate that ASCs-Exos can facilitate cutaneous wound healing via optimizing the characteristics of fibroblasts. Our results provide a new perspective and therapeutic strategy for the use of ASCs-Exos in soft tissue repair.