# The impact of common redox mediators on cellular health: a comprehensive study

## TL;DR

This study examines how common redox mediators affect cell health, showing that high concentrations can increase harmful molecules and reduce cell viability.

## Contribution

The study provides a detailed analysis of how specific redox mediators impact cell health at varying concentrations.

## Key findings

- ROS levels increase in all cell types when mediator concentration exceeds 1 mM.
- Cell viability decreases significantly at higher mediator concentrations.
- Cell migration is only affected at the highest concentrations of each mediator.

## Abstract

Electrochemistry has become a key technique for studying biomolecular reactions and dynamics of living systems by using electron-transfer reactions to probe the complex interactions between biological redox molecules and their surrounding environments. To enable such measurements, redox mediators such as ferro/ferricyanide, ferrocene methanol, and tris(bipyridine) ruthenium(ii) chloride are used. However, the impact of these exogeneous redox mediators on the health of cell cultures remains underexplored. Herein, we present the effects of three common redox mediators on the health of four of the most commonly used cell lines (Panc1, HeLa, U2OS, and MDA-MB-231) in biological studies. Cell health was assessed using three independent parameters: reactive oxygen species quantification by fluorescence flow cytometry, cell migration through scratch assays, and cell growth via luminescence assays. We show that as the concentration of mediator exceeds 1 mM, ROS increases in all cell types while cell viability plumets. In contrast, cell migration was only hindered at the highest concentration of each mediator. Our observations highlight the crucial role that optimized mediator concentrations play in ensuring accuracy when studying biological systems by electrochemical methods. As such, these findings provide a critical reference for selecting redox mediator concentrations for bioanalytical studies on live cells.

A compehrensive study on the effects of electrochemical mediators on cellular health that highlights detrimental mediator concentrations shown through studies on reactive oxygen species, cell migration, and cell growth and viability.