 This study demonstrates the potential of engineered mesenchymal stem cell-derived exosomes, UCMSC-XO-ENIS, as a novel therapeutic strategy for the promotion of angiogenesis and tissue repair in chronic diabetic wounds. UCMSC-XO-ENIS significantly improved the rate of wound closure and enhanced vascular neogenesis and matrix remodeling in diabetic mice. Furthermore, UCMSC-XO-ENIS also improved the inflammatory profile at the wound site and modulated the associated immune microenvironment, thus significantly promoting tissue repair. This article was authored by Xinzhou, Luicinthu, Hizhou, and others.