Electrophysiological properties of iCell cardiomyocytes obtained by automated patch clamp

Pluripotent stem cell-derived cardiomyocytes, iCells® Cardiomyocytes, were biophysically and pharmacologically characterized with planer automated patch clamp using the QPatch. iCells Cardiomyocytes are differentiated from human induced pluripotent stem cells. They are differentiated in large numbers and cryo-preserved, which make them highly suitable for automated patch clamping and facilitates their use in drug screening. Here we present the results obtained during assay optimization of the cell culture, assay set-up on the QPatch as well as biophysical and pharmacological validation of the cardiac currents. Implementing optimal cell culture routines, the iCells Cardiomyocytes demonstrated spontaneous rhythmical contractions indicating functional properties of adult cardiomyocytes. We tested the cells in two different QPatch recording modes; single-hole recordings and multi-hole recordings where up to ten cells are patched at the same time and the total current is measured per site. Three different types of currents were studied including sodium, calcium and potassium. By using specific buffer solutions and changing the voltage protocols it was possible to characterize calcium, and sodium currents from the same cell. Our study showed that iCells Cardiomyocytes can successfully be applied to the QPatch. The recorded currents are similar to human cardiomyocytes and the response to known pharmacology is as expected. Using the QPatch we believe that iCells Cardiomyocytes have great potential for safety screening and other cardiovascular investigations early in the drug discovery process.