Optical imaging in disease diagnosis and treatment benefits from high spatiotemporal resolution and the availability of numerous optical agents. However, many optical imaging probes are cleared by the reticuloendothelial system, which can lead to probe accumulation in the liver and spleen and hence organ toxicity. By contrast, renal-clearable optical agents (RCOAs) are rapidly excreted from the body via the kidneys, undergoing minimal metabolism. In this Review, we discuss the design principles of RCOAs, with a focus on imaging and disease theranostics (the combination of diagnosis and therapy). Renal excretion of RCOAs makes them intrinsically suitable for targeted kidney imaging, including passive monitoring of the glomerular filtration rate and detection of early kidney injury biomarkers. The pharmacokinetics of RCOAs can further be tailored to prolong their circulation in the blood, allowing deep tumour penetration and high-contrast tumour imaging. Finally, we discuss intraoperative image-guided surgery and optical urinalysis, and suggest future applications of RCOAs.

疾病诊断和治疗中的光学成像受益于高时空分辨率和众多光学试剂的可用性。然而，许多光学成像探针被网状内皮系统清除，这会导致探针在肝脏和脾脏中积累，从而导致器官毒性。相比之下，肾脏可清除的光学试剂 (RCOA) 会通过肾脏迅速排出体外，代谢最少。在这篇综述中，我们讨论了 RCOA 的设计原则，重点是成像和疾病治疗诊断学（诊断和治疗的结合）。RCOA 的肾脏排泄使它们本质上适用于靶向肾脏成像，包括肾小球滤过率的被动监测和早期肾损伤生物标志物的检测。可以进一步调整 RCOA 的药代动力学，以延长其在血液中的循环，从而实现深入的肿瘤穿透和高对比度的肿瘤成像。最后，我们讨论了术中影像引导手术和光学尿液分析，并建议了 RCOA 的未来应用。