Bioengineering of Novel Organotypic 3D Human Liver Tissue Model for Drug-Induced Liver Injury and Toxicity Studies

Camden HolmJoseph FinelliMateo FrareAlex ArmentoSeyoum Ayehunie^*

• MatTek Corporation, Ashland, Massachusetts, United States

In drug development, liver failure is the cause of approximately 30% of post marketing withdrawals of pharmaceuticals. In this study, we developed a novel human three-dimensional (3D) liver tissue model by seeding adult primary human hepatocytes onto cell culture inserts under Air-Liquid Interface (ALI) condition for weeks. This bioengineer organotypic liver tissue model features distinct apical and basolateral surfaces. The developed tissue model is polarized and well stratified and shows phenotypic and morphological similarity that recapitulates the native tissue architecture. Further characterization of the tissue model showed higher expression of liver-specific genes involved in drug transport, drug metabolism, and clearance. The utility of the tissue model for drug toxicity studies was demonstrated by comparing the 3D liver model with routinely used monolayer hepatocytes and liver spheroids. The model's utility for drug-induced liver toxicity was investigated by exposing the 3D human liver tissue model to test drugs with known human responses. The model's application for drug-induced liver injury was evaluated using liver function test biomarkers such as release of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) into the culture media. Barrier integrity (TEER) measurement was also used as an additional marker to monitor tissue damage. Functionally, the tissue model was able to metabolize drugs such as Midazolam, a substrate for CYP3A4 enzyme, to its metabolite, 1hydroxymidazolam. Repeated treatment of the tissue with Fialuridine, a clinically failed anti-hepatitis B drug known for causing liver failure or severe liver toxicity in humans, resulted in compromised barrier, reduced albumin release, and an increase in ALT and AST levels in a time and concentration dependent manner. These strongly suggest the model's physiological relevance and functionality in predicting drug responses in humans. Thus, the engineered organotypic human liver tissue model which can be cultured for weeks and produced in a semi-high throughput format creates an opportunity to study drug-induced liver toxicity in an in vitro microenvironment. The reconstructed 3D liver tissue model can serve as a tool for alternative methods intended to reduce animal use in experimentation.