Cell sources : Microphysiological 2-organ chips were obtained from TissUse (Berlin, Germany). Every circuit was composed of two 96-well compartments (of which one equipped with a reservoir holder) and 3 on-chip micropumps. Every compartment was filled with 300 µl of Lonza hepatocyte complete medium (HCM) (Lonza, Verviers, Belgium) with 10% premium-grade FBS (VWR, Radnor, PA, USA).
Liver spheroid formation : PHH were thawed in human cryopreserved hepatocyte thawing medium (Lonza), NPC were thawed in CP medium (BioIVT). After centrifugation for 10 minutes at 100 g cells were resuspended in Lonza HCM + 10% FBS and counted using a hemocytometer (Nano-entek, Waltham, MA, USA).