Mesenchymal stem cell-derived exosomes: versatile nanomaterials for skin wound treatment

Accumulating studies reveal that mesenchymal stem cells (MSCs) promote skin wound healing mainly through the paracrine effects. Exosomes, one of the crucial paracrine mediators in wound healing, are cell-derived nanosized membranous vesicles containing diverse bioactive cargoes. With the potent ability of modulating skin cell behaviors, MSC-derived exosomes (MSC-Exos) are regarded as a promising nanomaterial for regenerative wound therapy. Under hostile conditions, MSC-Exos are efficient in protecting skin cells from severe damage and restoring their function. According to recent studies, MSC-Exos possess remarkable pro-healing effects in a variety of skin wounds, typically resulting in increased wound closure, inhibited scar tissue formation, and better restoration of skin function. To further enhance the therapeutic potential of MSC-Exos, the development of applicable pretreatment strategies and the optimization of exosome delivery are under intensive investigation. Herein, we summarize current research progress of MSC-Exos for skin wound treatment, with an emphasis on the biological effects of these nanovesicles, the repair mechanisms, and future challenges in clinical translation.