Vascular lung triculture organoid via soluble extracellular matrix suspension

Scaffold-free tissue engineering is desired in creating consistently sized and shaped cell aggregates but has been limited to spheroid-like structure and function, thus restricting its use in accurate disease modeling. Here, we show formation of a viable lung organoid from epithelial, endothelial, and fibroblast stable cell lines in suspension culture supplemented with soluble concentrations of extracellular matrix proteins (ECM). We demonstrate the importance of soluble ECM in organotypic patterning with the emergence of air space-like gas exchange units, formation of branching, perfusable vasculature, and increased 3D growth. Our results show a dependent relationship between enhanced fibronectin fibril assembly and the incorporation of ECM in the organoid. Endothelial branching was found to depend on both soluble ECM and fibroblast. We successfully applied this technology in modeling lung fibrosis via bleomycin induction and test a potential antifibrotic drug in vitro while maintaining fundamental cell-cell interactions in lung tissue. Our human fluorescent lung organoid (hFLO) model accurately represents features of pulmonary fibrosis which were ameliorated by fasudil treatment. We demonstrate a 3D culture method with potential of creating organoids from mature cells, thus opening avenues for disease modeling and regenerative medicine, enhancing understanding of lung cell biology in health and lung disease.