PEDOT: PSS-Modified Organic Flexible and Implantable\nMicroelectrode for Internal Bi-Directional Electrophysiology of Three-Dimensional\nCardiomyocyte Spheroid

Three-dimensional\n(3D) cardiomyocyte spheroids are essential models\nto replicate cardiac structural and functional features in vitro.\nHowever, conventional planar and rigid microelectrode arrays (MEAs)\nsuffer from low-quality electrophysiological recording of 3D cultures,\ndue to limited contact areas and weak coupling between cells and MEA\nchips. Herein, we developed a PEDOT: PSS-modified organic flexible\nand implantable MEA (OFI-MEA) coupled with a self-developed integrated\nbiosensing platform to achieve high-throughput, long-term, and stable\nbidirectional internal electrophysiology in 3D cardiomyocyte spheroids.\nElectrostimulation enhanced the functional performance of the 3D cardiomyocytes,\ncausing a remarkable 2.69-fold increase in frequency. Furthermore,\ntime-frequency analysis of the multisite electrophysiological signals\nto highlight diverse cell activity patterns in the spheroids. It provides\na powerful tool to record electrophysiological signals of 3D cardiomyocyte\nspheroids, allowing continuing evaluation of cardiac dynamics and\nregulation of electrical signals, providing a novel evaluation strategy\nfor cardiac disease model construction, drug screening, and cardiological\nresearch.