Electrochemical Evaluation of Three-dimensional Cell Models

Three-dimensional (3D) cultured cells, such as spheroids and organoids, have been recognized as highly relevant in vitro tissue models. In addition, recent advances in microfabrication techniques have facilitated the development of microphysiological systems (MPS), in which cells are cultured in a microfluidic device that mimics the physiological environment and promotes the development of tissue-like structures. To make effective use of these in vitro models, techniques are needed that can assess the activities of the cells. Electrochemical sensors are promising due to their ease of miniaturization, label-free and real-time measurement of cell-derived molecules. Here we review the electrochemical assessment of 3D cultured cells using different types of electrochemical devices such as probe electrodes, electrode arrays, and electrochemical imaging methods. In addition, recent advances in the integration of electrochemical sensors into MPS are presented. Finally, the challenges and prospects for advancements in 3D culture systems integrated with electrochemical devices are discussed.