Activatable Optical Probes for Fluorescence and Photoacoustic Imaging of Drug‐Induced Liver Injury

Drug-induced liver injury (DILI) is a significant cause of acute liver injury and remains a major concern in drug discovery and clinical use. Optical imaging, including fluorescence imaging and photoacoustic imaging, has been widely used for the early and accurate diagnosis of DILI. Activatable optical probes can detect lesion-specific molecular alterations with high sensitivity and a high signal-to-noise ratio, offering a precise way to evaluate DILI. This review summarizes recent progress in the development of activatable optical probes equipped with fluorescence or photoacousitc imaging capabilities for the diagnosis of DILI in living organisms. The designs and applications of these activatable optical probes are categorized and discussed according to the lesion-specific molecular alterations of the injured liver, including reactive nitrogen species (RNS), reactive oxygen species (ROS), reactive sulfur species (RSS), and enzymes. The present challenges and perspectives to further advance them into clinical applications are also presented.