Stimulus-responsive tumor supramolecular nanotherapeutic system based on indocyanine green

Indocyanine green (ICG), a clinical near-infrared fluorescent probe, has the potential to be used as an integrated diagnostic and therapeutic agent for tumors. In this study, ICG-COOH-TK was obtained by connecting ICG molecules through stimulus-responsive thioketone (TK) bond, which can self-assemble into nanoparticles in water. Under 808 nm near-infrared light irradiation, the molecule exhibited excellent photothermal conversion efficiency, as well as better photostability and in vivo circulation stability than free ICG. The nanoparticle can respond to reactive oxygen species (ROS) overexpression in the tumor microenvironment and release ICG upon disassembly, resulting in significantly enhanced fluorescence emission at the tumor. In vitro cell experiments demonstrated excellent biocompatibility and photothermal killing effect on cancer cells, indicating that this molecule can serve as a diagnostic and therapeutic agent for fluorescence-guided tumor photothermal therapy.