A reticuloendothelial system-stealthy dye-albumin nanocomplex as a highly biocompatible and highly luminescent nanoprobe for targeted in vivo tumor imaging

A reticuloendothelial system (RES)-stealthy nanoprobe for enhanced tumor imaging is a longstanding pursuit. In this study, a nanocomplex comprising albumin and dye is assembled without crosslinker use. The nanocomplex shows intense luminescence with a photoluminescence quantum yield of up to 0.39 and a large Stokes shift of >130 nm. The nanocomplex also exhibits higher stability against hydrolysis than indocyanine green during the 14 days test. The nanocomplex shows favourable high biocompatibility and can be used for cell labelling. Remarkably, the nanocomplex exhibits six times higher tumor accumulation than that in the liver and spleen. At 96 h post-injection, the nanoprobe is still observable and gives a clear imaging of tumors, which can help in convenient diagnosis post-injection.