Setup of human liver-chips integrating 3D models, microwells and a standardized microfluidic platform as proof-of-concept study to support drug evaluation.

Human 3D liver microtissues/spheroids are powerful in vitro models to study drug-induced liver injury (DILI) but the small number of cells per spheroid limits the models' usefulness to study drug metabolism. In this work, we scale up the number of spheroids on both a plate and a standardized organ-chip platform by factor 100 using a basic method which requires only limited technical expertise. We successfully generated up to 100 spheroids using polymer-coated microwells in a 96-well plate (= liver-plate) or organ-chip (= liver-chip). Liver-chips display a comparable cellular CYP3A4 activity, viability, and biomarker expression as liver spheroids for at least one week, while liver-plate cultures display an overall reduced hepatic functionality. To prove its applicability to drug discovery and development, the liver-chip was used to test selected reference compounds. The test system could discriminate toxicity of the DILI-positive compound tolcapone from its less hepatotoxic structural analogue entacapone, using biochemical and morphological readouts. Following incubation with diclofenac, the liver-chips had an increased metabolite formation compared to standard spheroid cultures. In summary, we generated a human liver-chip model using a standardized organ-chip platform which combines up to 100 spheroids and can be used for the evaluation of both drug safety and metabolism.