Microfluidic 3D Cell-Culture Liver Chip with Integrated Chemical Gradients for Predictive Cholestatic Hepatotoxicity Screening

We present a polydimethylsiloxane (PDMS) microfluidic liver chip that enables rapid self-assembly of HepaRG cells into uniform 3D spheroids through microstructure confinement. The integrated passive branching gradient network supports six parallel dosing conditions per run. This platform produces highly uniform spheroids, demonstrates enhanced 3D sensitivity compared with 2D cultures, and allows quantitative mapping of matrine/oxymatrine ratio effects on cell viability and liverspecific functions such as albumin (ALB) secretion. Fabricated via standardized soft lithography with a sidewall-smoothing PDMS overcoat, the device ensures reproducible performance and supports streamlined throughput from early-stage drug discovery to preclinical drug-induced liver injury (DILI) risk assessment.