Label-Free 3D Holotomography and AI Quantification of Macrophage Inflammation Induced by Urban Particulate Matter

Objectives: Particulate matter (PM) is well established as an environmental hazard linked to an increased risk of disease. Although numerous studies have explored PM-induced cellular responses, a comprehensive understanding of PM toxicity requires integrating advanced imaging techniques with quantitative biochemical assays. Methods: Herein, we address this gap by combining these techniques with quantitative and functional assays to investigate the cellular effects of PM. PM collected from South Korea was used to assess toxicity in macrophages exposed to PM-containing medium. Three-dimensional (3D) holotomography revealed PM distribution and microstructural changes in cells following exposure. Results: Cell viability and inflammation analyses across PM concentrations highlighted its harmful effects. Lipid metabolism and mitochondrial dysfunction assays helped elucidate the underlying mechanisms, whereas a comparative study of oxidative potential between PM and gold nanoparticles (AuNPs) further demonstrates PM-induced hazards. Oxidative stress drove PM-induced physicochemical changes in macrophages. The oxidative potential of PM is a measurable factor that determines its oxidative stress properties. In addition, PM contains several components including transition metals and organic chemicals. Metallic components in PM particularly exhibited redox activity associated with oxidative stress and inflammation. Conclusion: Overall, our findings advance the mechanistic understanding of PM-cell interactions and introduce a novel methodological paradigm for studying the toxicological effects of environmental pollutants.