Renal-clearable probes for in vivo imaging of acute kidney injury

Acute kidney injury (AKI) is a serious syndrome with high morbidity and mortality, yet its early detection remains challenging due to insensitive clinical biomarkers, driving an urgent need for technologies enabling early, non-invasive, and visual monitoring. Renal-clearable probes offer promising tools for early diagnosis of AKI. In this review, we focus on the physicochemical determinants that determine renal clearance, elucidating the design principles of renal-clearable probes. We further discuss how three classes of probes (always-on, activatable, and dynamic) translate AKI-associated molecular events into in vivo images. Finally, the opportunities and challenges for their theranostic application and clinical translation are also considered.