T1/T2-weighted magnetic resonance imaging and SPECT imaging guided combined radioisotope therapy and chemotherapy using functionalized reduced graphene oxide-manganese ferrite nanocomposites

Abstract 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-MnFe 2 O 4 ) nanocomposites via a hydrothermal reaction, and modify nanocomposites with polyethylene glycol (PEG) to improve its biocompatibility. Interestingly, PEGylated RGO-MnFe 2 O 4 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 125 I labeled RGO-MnFe 2 O 4 -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 131 I co-loaded RGO-MnFe 2 O 4 -PEG nanocomposites, significant inhibiting the tumor growth after intravenous injection. Moreover, 131 I- RGO-MnFe 2 O 4 -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.