▎ 摘　　要

Multimodal imaging using nanomaterials in a single platform will bring hopeful for patients, and provide exact information including the tumor location and size for doctors. Herein, we synthesize reduced graphene oxide-manganese ferrite (RGO-MnFe2O4) nanocomposites via a hydrothermal reaction, and modify nanocomposites with polyethylene glycol (PEG) to improve its biocompatibility. Interestingly, PEGylated RGO-MnFe2O4 nanocomposites possess excellent T1/T2 weighted magnetic resonance imaging (MRI) of mice bearing 4T1 tumor after intravenous (i.v.) injection. After additional radioisotope labeling, SPECT imaging of I-125 labeled RGO-MnFe2O4-PEG nanocomposites exhibit high tumor accumulation. Under the guidance of MRI/SPECT imaging, in vivo combined radioisotope therapy (RIT) and chemotherapy is carried out using anticancer drug doxorubicin and I-131 co-loaded RGO-MnFe2O4-PEG nanocomposites, significant inhibiting the tumor growth after intravenous injection. Moreover, I-131-RGO- MnFe2O4-PEG/DOX nanocomposites cause no obvious toxicity to treated mice after 60 days post injection. Our study further promote the biomedical applications of nano-graphene based nanocomposites. (C) 2019 Elsevier Ltd. All rights reserved.