Exosomes from human umbilical cord blood accelerate cutaneous wound healing through miR-21–3 p-mediated promotion of angiogenesis and fibroblast function - Hu, Y; Rao, S S; Wang, Z X; Cao, J; Tan, Y J; Luo, J; Li, H M; Zhang, W S; Chen, C Y; Xie, H (Theranostics, 2018)