Rapid Clearance of IR783 and Methyl‐β‐cyclodextrin Complex for Improved Tumor Imaging

Abstract

AbstractNear‐infrared (NIR) fluorescence cancer imaging with targeted NIR fluorophores holds considerable promise for accurate detection and cancer diagnosis. Among the various NIR heptamethine cyanine dyes reported previously, IR783 as a single small molecule has been widely used for tumor‐targeted imaging without the additional conjugation of targeting moieties. Despite the potential advantages of IR783, the major problems, such as its non‐specific uptake in normal tissues/organs and slow clearance, remain to be solved. A key determinant of sensitivity and detectability in tumor imaging is the improvement of the tumor‐to‐background ratio (TBR). Herein, a simple and effective supramolecular complex self‐assembled from IR783 and methyl‐β‐cyclodextrin is developed to improve tumor imaging accompanied by rapid clearance from the body. The IR783‐cyclodextrin complex allowed for rapid whole body biodistribution, which remarkably reduced non‐specific background uptake, and thus increased the TBR value within 24 h post‐injection. Therefore, this strategy is applicable in combination with many different types of carbocyanine dyes for improved tumor imaging.