To achieve cell-free tissue regener

To achieve cell-free tissue regeneration, cell-free regenerative medicine should bear the biochemical and physical cues that can induce wound healing. One of the possible biochemical cues is the exosomes secreted by the cells, which are nanoparticles (30–200 nm) to mediate local and systemic cell-cell communication through the transfer of mRNAs, miRNAs, and proteins. Previous studies have shown that exosomes play pivotal roles in refractory wound healing activities, such as immunomodulation and angiogenesis. Among them, exosomes derived from human umbilical cord MSCs (hUCMSCs) have been reported to exert proangiogenic effects and accelerated diabetic wound healing. Excitingly, the human umbilical cord is an attractive source of UCMSCs and possesses several distinct advantages: no risk to donors, easy accessibility, and a low incidence of graft-versus-host disease.