Dual-Responsive Fluorescent Probe for Fluorescence Imaging of Superoxide Anion and Nitric Oxide During Macrophage Foam Cell Formation

Foam cell formation of macrophages is a core pathological event in the progression of atherosclerosis. Investigating the changes in active molecules during macrophage foaming is critical for the early warning and mechanistic research of atherosclerosis. Superoxide anion (O2•−) and nitric oxide (NO) are two typical representatives of these active species; evaluating the fluctuations of O2•− and NO during macrophage foaming is vital for understanding the early diagnosis and pathological mechanisms of atherosclerosis. Herein, we report a fluorescent probe for the detection of O2•− and NO concentration changes based on the quenching effect of the urea bond and trifluoromethanesulfonate group on the fluorophore. MB-ROS features favorable sensitivity, selectivity and biocompatibility, enabling imaging of O2•− and NO fluctuations in macrophages. It was further validated in ox-LDL-stimulated foam cell models to visually track abnormal ROS/RNS changes during foam formation. This work offers a reliable chemical imaging tool to uncover redox imbalance underlying early atherosclerotic macrophage foaming.