Gastruloids enable modeling of the earliest stages of human cardiac and hepatic vascularization

Here we show that spatially micropatterned human pluripotent stem cell (hPSC)-derived gastruloids enable in vitro modeling of the earliest developmental stages of cardiac vascularization, roughly corresponding to the first three weeks of in vivo human development (Carnegie Stages 9 and 10). Using clues from developmental biology, we identified a growth factor/small molecule cocktail, that when added to micropatterned hPSCs, generated a spatially organized, branched, and lumenized vascular network within a multi-lineage cVO comprising endocardial, myocardial, epicardial, and neuronal cell types.