Microenvironment optimization enables kidney organoid longevity with epithelial-endothelial joint basement membrane...

Kidney organoids degrade in long-term culture and lack joint basement membranes between epithelial and endothelial cells characteristic of renal tissue. Here we show that these limitations can be overcome in static cultures simply by optimizing the microenvironment. Supplementing standard media with tubular-enhancing factors (TEFs) dramatically improves organoid yield and longevity, while vascular-enhancing factors (VEFs) and replating increases endothelial cell yield and invasiveness. A transcriptomic and imaging atlas demonstrates maintenance of nephron structures for six months with increased metabolism, signaling, differentiation, and aging-related pathways. In addition to adherent cultures, these media also enable organoid differentiation and vascularization in suspension cultures and hydrogels. Remarkably, addition of TEFs and VEFs to organoids in suspension induces self-assembly of joint basement membranes between endothelial cells and podocytes or tubules, a major feature of renal tissue. Microenvironment optimization thus enables longitudinal stabilization and higher-order vascularization of kidney organoids, offering a diverse resource for long-term studies and tissue engineering applications.