The liver, although equipped with an excellent detoxification system, gets injured with high doses of drug intake, leading to acute liver failure.  The conventional preclinical animal studies and in vitro cell based drug-screening hardly match with the in vivo situation in human, leading to early stage failures during drug development. Therefore, it is highly essential to develop a tissue engineered-liver model that mimics the in vivo physiological micro-environment of native liver more accurately, which can be automated at micro-scale for rapid, high-throughput hepatoxicity screening of novel drugs. The project “MicroLiver” aims to generate state-of-the-art microfluidics-based bi-compartmentalized Janus hydrogel droplets (containing two distinct halves) as a patterned co-culture system for high-throughput drug screening. Glycosaminoglycans (GAGs) and collagen being the predominant extracellular matrix (ECM) components of liver and hepatocyte-endothelial cell combinations constituting almost 80% of total liver mass, set up a perfect recipe to establish hepatomimetic biomaterials based co-culture model in vitro. Chitosan, a GAG-mimic, is used extensively for liver tissue engineering along with the collagen and here we establish fabrication of Janus droplet using their blend. Each compartment of the Janus droplet is being used to encapsulate primary hepatocytes and dermal microvascular endothelial cells (hDMECs) separately to establish 3D co-culture. A microfluidic Janus droplet generator device is appropriately designed and fabricated for monodisperse generation of hydrogel droplets (of photo-crosslinkable chitosan/collagen prepolymer) to co-encapsulate hepatocytes and hDMECs. Such bi-compartmentalized co-culture system is being optimized in terms of hepatocytes/hDMECs cell number, cell ratio and media requirements to establish effective cell-cell and cell-materials interactions for long-term maintenance of liver functions, which could serve as an appropriate mimic of miniature liver lobule, referred as “microliver”.Once the 3D microliver model is established, they will be validated further as a platform for novel microscopy-based high content screening (HCS) assay to predict drug-induced hepatotoxicity. Here, we propose to employ five fluorescent probe panels for automated profiling of up to six hepatotoxicity end-points parameters representative of general cellular toxicity, mitochondrial integrity and lysosomal activity, at different exposure time-points for five model drugs in a multi-well plate format. The expected outcome of this study will be development of a first of its kind bi-compartmentalized hydrogel based co-culture system for production of bioartificial microliver construct and validation of a novel high-content screening tool for drug-induced hepatotoxicity. Acknowledgments: This work was supported by the Portuguese Foundation for Science and Technology (FCT) R&D grant POCI-01-0145-FEDER-016715 (PTDC/BBB-ECT/4317/2014) (DKB) for the project MicroLiver.