Theoretical analysis of the electrochemical systems used for the application of direct current/voltage stimuli on cell cultures

Endogenous electric fields drive many essential functions relating to cell proliferation, motion, differentiation and tissue development. They are usually mimicked in vitro by using electrochemical systems to apply direct current or voltage stimuli to cell cultures. The many studies devoted to this topic have given rise to a wide variety of experimental systems, whose results are often difficult to compare. Here, these systems are analysed from an electrochemical standpoint to help harmonize protocols and facilitate optimal understanding of the data produced. The theoretical analysis of single-electrode systems shows the necessity of measuring the Nernst potential of the electrode and of discussing the results on this basis rather than using the value of the potential gradient. The paper then emphasizes the great complexity that can arise when high cell voltage is applied to a single electrode, because of the possible occurrence of anode and cathode sites. An analysis of two-electrode systems leads to the advice to change experimental practices by applying current instead of voltage. It also suggests that the values of electric fields reported so far may have been considerably overestimated in macro-sized devices. It would consequently be wise to revisit this area by testing considerably lower electric field values. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

Endogenous electric fields play essential roles in functions such as cell proliferation, motion, differentiation, and tissue development, and are often mimicked in vitro using electrochemical systems. Analyzing these systems from an electrochemical standpoint can help harmonize protocols and improve understanding of the data produced. The complexity arising from high cell voltage applied to single electrodes, as well as the potential overestimation of electric field values in macro-sized devices, suggests the need for revisiting this area with lower electric field values.