Generation of a Scaffold-Free Three-Dimensional Liver Tissue via a Rapid Cell-to-Cell Click Assembly Process.

There has been tremendous interest in constructing in vitro liver organ models for a range of fundamental studies of cell signaling, metabolism, and infectious diseases, and as a commercial system to evaluate therapeutic drug discovery prioritization and toxicity. Although there has been progress toward studying two-dimensional hepatic function in vitro, there remain challenging obstacles to generate rapid and efficient scaffold-free three-dimensional multiple cell line coculture tissue models of liver. Herein, we develop and employ a strategy to induce specific and stable cell-cell contacts among multiple hepatic cell lines to generate 3D tissues through cell-surface engineering based on liposome delivery and fusion to display bio-orthogonal functional groups from cell membranes. We generate, for the first time, a three cell line coculture 3D liver tissue model by assembling hepatocytes, hepatic endothelial cells, and hepatic stellate cells via a rapid intercell click ligation process. We compare and analyze the function of the superior 3D liver tissue chips with 2D coculture monolayer by assessing mitochondrial metabolic activity and evaluating drug toxicity.