A Redox-Responsive Reversible Photoacoustic Molecular Probe for Visualizing Atherosclerotic Plaque Redox Status in Vivo

Atherosclerotic plaque stability is closely linked to the local redox status, particularly the imbalance driven by superoxide anion (O2•‒). However, non-invasively monitoring the dynamics of superoxide within plaques in vivo and evaluating the modulating effects of anti-inflammatory therapies remain challenging. This study reports a novel redox-responsive reversible photoacoustic probe, ReP, which exhibits reversible and selective photoacoustic signal switching in the near-infrared region in response to O2•‒ and glutathione (GSH). In vitro characterization demonstrated that ReP enables quantitative detection of O2•‒ and GSH with high selectivity. In an atherosclerosis mouse model, ReP successfully visualized the elevated superoxide levels within plaques following systemic inflammatory stimulation. More importantly, this probe could monitor the significant alleviation of plaque redox imbalance after anti-inflammatory treatment with dexamethasone. Collectively, ReP provides a valuable tool for in vivo assessment of plaque redox status and therapeutic efficacy.