Monitoring the cellular growth on a sensorized multi-well plate by using Impedance Spectroscopy measurements

The following project has been developed starting from a collaboration between the Department of Information Engineering (DEI) and the Department of Pharmaceutical and Pharmacological Sciences (DSF) of the University of Padova. The aim of the study is to understand how the cell adhesion to electrodes placed on a sensorized multi-well plate influences the electrical response. For this purpose, a versatile and non-invasive technique, i.e., Electrochemical Impedance Spec- troscopy, was used. I developed a low-cost and portable setup compared to the one available at the Department of Pharmacology. I integrated a potentiostat to perform the measurements with an Arduino board, which was used to sequentially select the wells on the plate. After collecting the measured data by monitoring the adhesion of a pool of CHO cells over time, each response was modeled and fitted with an equivalent electrical circuit. In particular, the study aimed to investigate which parameters are affected by the biological events occurring in the bulk and at the electrode-solution interface. In the case under examination, an increase in resistance was observed, due to the presence of cells on the electrodes, which hinder the passage of current. Simultaneously, a decrease in a capacitive component was detected, related to the fact that the number of cells deposited on the electrodes increases over time. After 3.5 hours of cell adhesion assay, the κ-receptors on the cell surface have been stimulated using the agonist peptide Dynor- phin A (1–17). Variation of electrical parameters have been detected, especially the presence of a spike in the first 10 minutes, when stimulation is expected to occur. Therefore, this study has allowed the detection of cells by the quantitative analysis of the variation of some key electrical parameters. The main future developments concern the stimulation of the receptors with other kinds of ligand and gain more knowledge on how they induce a variation in the electrical re- sponse. Moreover, it was observed that the stimulation phenomenon is too rapid to be detected with my setup. Hence, a new faster setup might highlight new insights.