Fig. 4: Generation of enhanced vascularized kidney organoids in UniMat.

a Confocal z-stack images for PODXL, LTL, and PECAM1 in kidney organoids cultured in AggreWell and UniMat. Scale bar = 50 µm (b) AngioTool outputs of abundance and character of vasculature of kidney organoids cultured in AggreWell and UniMat (reported as fold change relative to AggreWell-cultured organoids). (n = 10 organoids, mean ± SD). Significance by Student’s t-test: P = 1.1 × 10⁻⁸ (vessel % area), P = 7.9 × 10⁻¹¹ (junction density), P = 3.3×10⁻¹² (average vessel length). c qRT-PCR of PECAM1 expression of kidney organoids cultured in AggreWell and UniMat. (n = 5 independent experiments, mean ± SD). Significance by Student’s t-test: P = 1.8×10⁻⁵ (vessel % area). d Sequential individual confocal z-slice images of kidney organoids in AggreWell and UniMat, stained with PODXL and PECAM1. Scale bar = 20 µm. White arrows indicate invasion of PECAM1⁺ endothelial cells into PODXL⁺ podocyte clusters. e Quantification of percentage of PECAM1⁺ endothelial cells invasion into a glomerular-like structure in kidney organoids cultured in AggreWell and UniMat (n = 10 organoids, mean ± SE). Significance by Student’s t-test: P = 4.3 × 10⁻⁸ (vessel % area). f High-magnification sequential individual confocal z-slice images of kidney organoids cultured in UniMat, stained with PODXL and PECAM1. Scale bar = 20 µm. Yellow arrow indicates lumen-like structure of invaded PECAM1⁺ endothelial cells and white arrows indicate invasion of PECAM1⁺ endothelial cells into PODXL⁺ podocytes clusters. Source data are provided as a Source Data file.