A hepatic zonation chip with an oxygen concentration gradient embracing the spatial distribution of metabolic function

Abstract The development of hepatic in vitro models that replicate the physiological characteristics of liver tissue is critical for the accurate translation of drug test results. Current models often fail to mimic the spatial zonation by an oxygen concentration gradient in the hepatic acinus, limiting their ability to predict drug-induced hepatotoxicity. This study aimed to develop a hepatic zonation chip (H-chip) that replicates the oxygen gradient of the hepatic acinus, enhancing physiological relevance for drug testing applications. The H-chip was fabricated with a circular microfabricated chip chamber covered by oxygen-impermeable glass substrates, generating a radial oxygen concentration gradient through oxygen consumption by hepatic cells. This gradient mimics the portal-to-central oxygen distribution observed in vivo, enabling zone-specific hepatic functionality. We showed that the H-chip successfully reproduced the oxygen gradients found in the in vivo hepatic acinus along with corresponding cell cytocompatibility of hepatic cells. Notably, pericentral-specific hepatic functionality increased in the H-chip and decreased in the normoxia chip (N-chip). Spatial transcriptomic analysis revealed heterogeneous gene expression patterns aligned with local metabolic functions in each zone across the H-chip. Furthermore, toxicity evaluation of acetaminophen, a representative drug known for its spatial hepatotoxicity, revealed increased zonation-specific sensitivity in the H-chip, linked to elevated cytochrome P450 gene expression and toxic metabolite formation. These findings highlight the ability of the H-chip to replicate hepatic zonal characteristics, thus providing a robust platform for evaluating hepatotoxicity in drug testing. This platform promises to advance safer and more effective drug development by enabling more physiologically relevant assessments.