HYDRA: HYdrogel Dispensing with Robotic Automation for high throughput drug testing

The poor predictivity of traditional cell culture platforms hampers drug research and development efficiency. While organoids and organs-on-chip mitigate this problem by introducing biomimetic in-vitro microenvironments in late pre-clinical stages, there is a lack of biomimetic platforms in earlier stages, particularly for high-throughput imaging screening (HTS). Something as simple as a thin hydrogel layer would provide physiological stiffness and native-like biochemical cues. However, casting hydrogels inside the small-diameter wells of HTS plates creates high-curvature menisci that negatively affect cell seeding and microscopy readouts. Here, we present a solution to this problem: HYdrogel Dispensing with Robotic Automation or HYDRA. This method allows automatic dispensing and aspiration of hydrogel precursors while preventing meniscus formation. Using this approach, we can produce gelatin hydrogels with tunable stiffnesses and thickness at room temperature and in commercial HTS plates. Then, we validate HYDRA in dose-response studies for anti-cancer drugs nocodazole and paclitaxel using genetically engineered epithelial cells (HaCaT) and imaging-based HTS readout methods such as phase holography and fluorescence microscopy. Taken together, this work shows that pharmaceutical companies can readily apply HYDRA with their current infrastructure to produce more biomimetic and predictive HTS platforms.