ESPCI Paris 2 articles published in JoVE Biology In Vitro Three-Dimensional Sprouting Assay of Angiogenesis Using Mouse Embryonic Stem Cells for Vascular Disease Modeling and Drug Testing Georgios Galaris1, Jérémy H. Thalgott1, Eliott Teston1, Franck P.G. Lebrin1,2,3 1Einthoven Laboratory for Experimental Vascular Medicine, Department of Internal Medicine (Nephrology), Leiden University Medical Center, 2Institute Physics for Medicine Paris, INSERM U1273, ESPCI Paris, CNRS FRE 2031, 3MEMOLIFE Laboratory of Excellence and PSL Research University This assay utilizes mouse embryonic stem cells differentiated into embryoid bodies cultured in 3D-collagen gel to analyze the biological processes that control sprouting angiogenesis in vitro. The technique can be applied for testing drugs, modeling diseases, and for studying specific genes in the context of deletions that are embryonically lethal. Bioengineering Generation and Quantitative Characterization of Functional and Polarized Biliary Epithelial Cysts Latifa Bouzhir*1, Emilie Gontran*1, Lorena Loarca1, Mauricette Collado-Hilly1, Pascale Dupuis-Williams1,2 1Physiopathogénèse et traitement des maladies du foie, Université Paris-Saclay, Inserm U1193, 2ESPCI Paris, Université PSL Three-dimensional (3D) cellular systems are relevant models for investigating organogenesis. A hydrogel-based method for biliary cysts production and their characterization is proposed. This protocol unravels the barriers of 3D characterization, with a straightforward and reliable method to assess cyst formation efficiency, sizes, and to test their functionality.