Evaluating the Effect of Drug Compounds on Cardiac Spheroids Using the Cardiac Cell Outgrowth Assay in a Microphysiological System.

The ideal cell culture model should mimic the cell's physiology and the mechanical and chemical cues that are present in specific tissues and organs, within a convenient high-throughput format. A possible key feature for such models is to recapture the cell polarity, the interactions between cells, and the interactions between the cells and the elastic extracellular matrix (ECM) by orienting the cells in a three-dimensional (3D) matrix. A common method to create 3D cell environments is to let the cells aggregate into spheroids with a diameter of around 200 μm. A major challenge for 3D cell cultures is to perform quick and easy imaging of the dense cell population, especially non-invasively. This protocol explains how to take advantage of the number of cells growing out from cell spheroids over time as a readout of the effect of a drug. The assay is carried out in a microphysiological system where the cells experience in vivo-like fluidic conditions. The procedure is compatible with standard imaging techniques and can be performed non-invasively using light microscopy or as a complement to other fluorescent imaging assays.