Indocyanine Green Loaded Modified Mesoporous Silica Nanoparticles as an Effective Photothermal Nanoplatform

Photothermal therapy possesses great advantages for the treatment of drug-resistant tumors. Herein, Near Infrared (NIR)-triggered photothermal nanoparticles were developed through loading indocyanine green (ICG), a kind of NIR dye, into amino group-modified silica nanoparticles (SiO(2)-NH(2) NPs). SiO(2)-NH(2) NPs were prepared with immobilization of the amino groups into the framework of silica nanoparticles (SiO(2) NPs) by employing (3-aminopropyl)-triethoxysilane (APTES). Before and after the modification of the amino group, the particle sizes of SiO(2) NPs showed similar value, around 100 nm. ICG was further adsorbed into SiO(2)-NH(2) NPs by electrostatic attraction to enable SiO(2)-NH(2)@ICG NPs as a kind of photothermal agent. The loading rate of ICG to SiO(2)-NH(2) was greatly increased compared to unmodified SiO(2), and the stability of ICG was also improved. Moreover, the SiO(2)-NH(2)@ICG NPs exhibited efficient photothermal effects due to ICG transforming laser power into local heat through the connected ICG, when NIR laser irradiation turned on for a couple of minutes. Finally, the in vitro antitumor efficacy of SiO(2)-NH(2)@ICG NPs was investigated by recording cell proliferation rate and further chronicled the apoptotic morphology evidence by a Calcein-AM/PI fluorescent staining assay, indicating the efficient photothermal targeted therapy for the HepG2 tumor cells.