Two birds, one stone: host-guest complex of indocyanine green–β-cyclodextrin for fundus angiography

Indocyanine green (ICG) angiography is of great importance for ophthalmic diagnostic applications and is mainly used to check for choroidal vascular diseases. However, ICG fluorescence imaging probes aggregate in water because they have sulfonyl groups and can form dimers and oligomers. This effect thus reduces the fluorescence of the probes. Therefore, we have established a simple and effective way to prepare β-cyclodextrinmodified ICG (ICG–β-CD) via the host–guest assembly process. In contrast to ICG, ICG–β-CD avoided solution aggregation. Moreover, it exhibited improved absorption intensity. When used as an angiographic contrast agent for ophthalmic choroid examination and diagnosis in SD rats, the fluorescence imaging effect of ICG–β-CD on retinal and choroidal vessels was better than that of ICG on choroidal vessels. Therefore, ICG–β-CD is expected to achieve a "two birds with one stone" effect.