A Kidney Organoid Chip Facilitating Organoid Development and In Vitro Renal Fibrosis Modeling

Renal fibrosis is the inevitable and irreversible consequence for chronic kidney disease (CKD). While organoid technology shows promise for modeling this process, statically cultured kidney organoid remain restricted, lacking the structural complexity or microenvironmental dynamics required to recapitulate CKD-associated fibrosis, thereby limiting its applications to anti-fibrotic research. To address such bottleneck, we systematically leveraged microfluidic technology and developed a computer numerical control (CNC)-fabricated kidney organoid chip (KOC). Comprised of a reservoir chamber and an organoid culture chamber, the KOC generates stable, high-flow shear stress in the culture chamber via connection to a peristaltic pump, enabling rapid production of a large number of kidney organoids. Morphology and gene expression evaluation of organoids in the KOC revealed that flow shear stress enhances renal tubular epithelial development and induces endogenous vascular endothelial formation. For practical application, the KOC was used to establish an in vitro renal fibrosis model by introducing the pro-fibrotic inducer TGF-β1. Both protein and gene levels analyses confirmed the presence of extracellular matrix (ECM) deposition, epithelial-mesenchymal transition (EMT), and fibroblast-to myofibroblast transition (FMT) in this KOC-based fibrosis model, highlighting its potential as a valuable tool for anti-fibrotic drug development.