A microscale 3D printing glomerular spheroid-on-a-chip for modeling the pathophysiology of diabetic nephropathy

Diabetic nephropathy (DN) is driven by progressive dysfunction of the glomerular filtration barrier (GFB), yet current in vitro models inadequately capture its multicellular architecture and dynamic microenvironment. Herein, we present a glomerular spheroid-on-a-chip that integrates organoid-like cellular organization with microfluidic perfusion to mimic the pathophysiology of DN. The strategic integration of human mesangial cells (HMCs), a critical component often neglected in existing platforms, into triculture spheroids alongside conditionally immortalized human podocytes and human umbilical vein endothelial cells (HUVECs) significantly augments the structural integrity and functional recapitulation of the engineered GFB. A streamlined, cost-effective micro-3D printing strategy generates bowl-shaped PDMS microdevices that anchor spheroids for controlled lateral expansion under dynamic perfusion, establishing a biomimetic GFB with distinct vascular and urinary compartments. Under diabetic conditions, the platform faithfully recapitulates key pathological features of DN, including HMC expansion, podocyte injury and increased barrier permeability, while directly revealing the critical contribution of HMCs to filtration barrier dysfunction. Moreover, the system supports small-molecule therapeutic evaluation, underscoring its potential for mechanistic studies and preclinical drug screening. This work establishes a versatile and manufacturable platform that bridges static glomerulus spheroid cultures and dynamic, disease-relevant modeling of DN.