Work

An artificial macrophage reveals the impact of nitric oxide microenvironments on bacterial viability

Year: 2026

Type: preprint

Abstract: Nitric oxide (NO) emitted from immune cells such as macrophages plays an important role in combating bacterial pathogens. Yet studying ephemeral NO-mediated interactions in real time, quantitatively, and at the single-cell level has been technically challenging. Here we present an “artificial macrophage”: a live-cell imaging platform that overcomes these challenges by leveraging electrochemistry to generate micropatterned NO gradients at infection-relevant concentrations. We achieve this capability using a biocompatible electrocatalyst that selectively transforms ammonia into NO in biological media. Using Pseudomonas aeruginosa as a model NO-responsive pathogen, we show that the NO microenvironment, influenced by both extracellular NO concentrations and NO gradients experienced by cells, underpins NO’s bactericidal efficacy for individual surface-associated cells. Our results highlight that considering NO’s reaction-diffusion, rather than just its local concentration, is key to understanding how the extracellular microenvironment affects single-cell bacterial viability. Spatiotemporal control of NO microenvironments using our live-cell imaging platform will advance studies of diverse cell types that regularly encounter NO.

Source: ChemRxiv

DOI: 10.26434/chemrxiv.15010647/v1