Automated Large-Scale Spheroid Generation via Hanging-Drop and Efficient Transfer into Physiological Mimicking Microenvironment

We present a high-throughput three-dimensional (3D) cell culture workflow combining fully automated large-scale production of spheroids with an automated transfer into microwells loaded with an extracellular matrix mimicking hydrogel. The platform principle is based on dispensing nanoliter droplets of a homogeneously mixed cell suspension with a non-contact dispenser so that spheroids are generated via the hanging-drop method. Compared to previous work [1], [2] we optimized the setup for extended sample processing times of up to 45 minutes without negatively affecting the quality of spheroid generation. We reached a superior spheroid yield of 99.3 % while simultaneously generating highly consistent spheroids with a coefficient of variance below 8 %. Our novel harvesting workflow based on centrifugal drop transfer dramatically increased the efficiency to 100 % compared to previously reported 54.3 % [1].