Nanoscale (2020).
Aggregation of Superparamagnetic iron oxide (SPIO) nanoparticles (NPs) can greatly enhance magnetic resonance imaging (MRI) T2 weighted imaging and near-infrared (NIR) absorption in experiments. In this study, an Ac-Arg-Val-Arg-Arg-Cys(StBu)-Lys-CBT probe was designed and coupled with monodispersed carboxyl-decorated SPIO NPs to form SPIO@1NPs, which use it to intracellular self-aggregation. In vitro experiments showed that the self-aggregation of SPIO@1NPs was induced by a condensation reaction mediated by the enzyme furin in furin-overexpressing tumor cells. Moreover, the NPs in the aggregated state showed significantly higher MR r2 value and photothermal conversion efficiency than the NPs in the monodispersed state. Then, the SPIO@1NPs self-aggregation in vivo tumor, can achieve accurately MR T2 imaging-guided photothermal therapy, effectively killing cancer cells. We believe that this basic technique, based on tumor-specific enzyme-instructed intracellular self-aggregation of NPs, could be useful for the rational synthesis of other inorganic NPs for use in the fields of tumor diagnosis and treatment.
