Modular assembly of arterial organoids enables rapid blood perfusion to ameliorate ischemic diseases

Abstract Transplantation of vascular cells is a potential strategy for enhancing vascular regeneration in the treatment of ischemic diseases. However, its therapeutic application is limited by poor engraftment and insufficient vascular integration. Here, we develop a scalable methodology for generating suspensible, homogeneous arterial organoids from human induced pluripotent stem cells using a three-dimensional bioreactor system. These spheroidal arterial organoids constitute micron-scale vascular modules, consisting of a confluent layer of arterial-like endothelial cells closely associated with mural cells. Following local injection, we show that the modules assemble into larger vascular structures, where the spaces between adjacent modules form interconnected channels that support rapid perfusion. To evaluate the therapeutic potential of this approach, we apply arterial organoids in murine models of hindlimb ischemia and myocardial infarction. Upon delivery, we demonstrate that arterial organoids rapidly integrate with host vasculature, improving perfusion recovery and tissue repair compared with single-cell counterparts. Mechanistically, we find that implanted arterial organoids recruit vascular endothelial growth factor A-secreting macrophages, which remodel the local microenvironment and promote vascular regeneration. Collectively, our findings demonstrate that arterial organoids can self-organize into perfusable vascular networks in vivo and improve blood perfusion in ischemic tissues. This study provides an injectable organoid-based strategy for vascular regeneration in ischemic disease contexts.