Project Summary Intestinal epithelium is the fastest dividing tissue in the body, and the health of the cells can be easily impacted by environmental toxins and drugs. This organ system is therefore a prime target for biological testing of medicinal compounds, prebiotics and microbial products. An in vitro gut model that can precisely predict these impacts will reduce the burden of testing by diminishing reliance on animal models, minimizing the number of overlapping assessments and helping to eliminate unnecessary testing. To meet this need, Altis Biosystems Inc., an early stage biotechnology company, will collaborate with scientists at University of Washington to develop a novel 2-dimensional (2D) crypt platform that emulates the gut epithelium. Human primary intestinal epithelial stem cells will be patterned on the platform to mimic a gut epithelium possessing a stem-cell niche, and migratory proliferating and differentiating cells. This planar 2D platform will enable high-content/high-throughput assays in a rugged and reproducible manner. In this Phase I SBIR, this collaboration will generate 2D crypts with intervening regions of a differentiated cell monolayer, optimize the platform with a focus on quantitative strategies to benchmark performance, and perform small scale screens to demonstrate feasibility to advance to a Phase 2 project. The goal is to develop and benchmark a quantitative in vitro method that will enable investigators to efficiently evaluate the impact of compounds on intestinal stem cell proliferation and differentiation.