Scientists Grow Vascularized Lung and Gut Organoids Using Co-Developed Germ Layers

Organ development requires coordinated crosstalk between multiple germ layers, yet most organoid systems derive from a single lineage, lacking the vasculature and mesenchyme that are critical to tissue function and maturation. This study addresses that gap by co-differentiating mesoderm and endoderm simultaneously within the same iPSC-derived spheroid, recapitulating the concurrent development of these layers as it occurs in the embryo.

The key methodological insight was that BMP signaling levels could be titrated to precisely adjust the ratio of endodermal to mesodermal progenitors, thereby controlling the balance of epithelial and endothelial cell production. This single parameter tuned the organoid toward either lung or intestinal identity, demonstrating a surprisingly tractable control point for multilineage organoid specification.

Single-cell RNA sequencing revealed that endothelial and mesenchymal cells within these organoids acquired organ-specific gene expression signatures — lung endothelium differed transcriptionally from intestinal endothelium in ways that mirror in vivo distinctions. The analysis also identified key ligand-receptor pairs mediating endothelial specification, providing mechanistic insight into how the local microenvironment shapes vascular identity during organogenesis.

Functionally, the vascularized organoids outperformed their avascular counterparts across multiple metrics: tissue-specific barrier function, enhanced cellular diversity, more advanced epithelial maturation, and formation of alveolar structures when cultured on engineered lung scaffolds. Upon transplantation into immunocompromised mice, the organoid vasculature anastomosed with host circulation while retaining its organ-specific identity, and this perfusion further drove maturation of the epithelial compartment.

As a proof-of-concept disease application, the researchers used vascularized lung organoids carrying FOXF1 mutations — associated with alveolar capillary dysplasia — to uncover previously uncharacterized defects in endothelial-epithelial crosstalk. This demonstrates the platform's power to illuminate human disease mechanisms that could not be studied in avascular organoid systems. The approach is broadly generalizable and represents a significant advance toward physiologically faithful organ models for drug testing, disease modeling, and regenerative medicine.