Real-time assessment of renal oxidative injury via a hydroxyl radical-responsive photoacoustic imaging probe.

Diabetic kidney injury, a severe complication of diabetes, involves complex pathological mechanisms where the role of hydroxyl radicals (•OH) remains insufficiently explored due to the lack of suitable detection tools. To address this gap, a hydroxyl radical-activated near-infrared photoacoustic probe, OHSO3, was developed. In vitro validation confirmed its high sensitivity, excellent selectivity, and low cytotoxicity. Leveraging sulfonate group-enhanced hydrophilicity for favorable renal clearance, OHSO3 enabled non-invasive, real-time imaging of renal •OH in a diabetic mouse model. The probe successfully visualized elevated •OH levels in injured kidneys and quantitatively monitored their attenuation following metformin treatment. This study provides not only a reliable molecular tool for •OH-specific imaging but also a promising strategy for studying oxidative dynamics and evaluating therapies in diabetic nephropathy.