PROJECT SUMMARY Nine out of ten drug candidates that are shown to be safe and effective in animal testing ultimately fail in human trials. A great deal of work over the last decade has focused on leveraging pluripotent stem cells to create human organoids and microphysiological organ-on-chip models which present a lower cost, ethical, scalable, and more physiologically-relevant alternative to animal testing. These organoids are 3D tissues representing the full range of cell phenotypes present in various human organ systems. With the recent passage of the FDA Modernization Act 2.0, congress has allowed FDA to accept organoids as alternatives to animal testing for drug approvals. Organoid model development has also been broadly prioritized across the NIH. As organoids move toward translational practice, there is a large and growing unmet need for new bioreactor tools designed specifically for organoid culture. Mosaic is leveraging fifteen years of microfluidics research and high-volume manufacturing experience to create a versatile, programmable, easy-to-use, and scalable perfusion bioreactor platform for microphysiological systems. We are partnering with early adopters in the emerging organoid and cell therapy industries as well as manufacturing partners with expertise in injection molding microfluidic consumables. Our platform overcomes several major bottlenecks in the development and scalable application of organ-on-chip assays for drug discovery. Our microfluidic consumable follows a standard SBS plate form factor, allowing it to be integrated into broader laboratory automation workflows. Our low-cost electronic pressure manifold leverages recent advances in MEMS technology to precisely drive fluids and actuate on-chip valves across a standardized microfluidic consumable interface. In this Phase I, we will validate this platform by demonstrating iPSC cardiovascular organoid differentiation and observation under perfusion culture. We will show that a single bioreactor yields hundreds of healthy, phenotypically-consistent vascularized cardiac organoids, and that these organoids can be differentially dosed with pharmacological agents under physiologically-relevant perfusion conditions. We will develop an intuitive scripting interface for automating cell culture and screening protocols. Our first product (Phase II) is an R&D hardware and software platform for microfluidic bioreactor automation compatible with standard live cell imaging microscopes. Our long-term goal is to develop a fully-integrated system with imaging and microfluidic automation, along with a catalog of standard microfluidic consumables for a variety of use cases including hepatocyte culture for toxicity screening, tumor spheroid perfusion, suspension culture for immunotherapy production, and general cell biology.