Graphene oxide / MnWO4 nanocomposite for magnetic resonance / photoacoustic dual-model imaging and tumor photothermo-chemotherapy.

A multifunctional theranostic nanoplatform based on nanosized graphene oxide (GO) and MnWO 4 has been developed by in situ growth of MnWO 4 nanoparticles onto GO surfaces in a hyperthermia polyol medium containing polyethylene glycol (PEG). In comparison with GO and MnWO 4 /PEG, the near infrared (NIR) absorbance of the produced GO/MnWO 4 /PEG nanocomposite is significantly improved, resulting in an enhanced photothermal conversion capability and a good photoacoustic (PA) imaging performance. It is worth to note that the longitudinal relaxivity r 1 of GO/MnWO 4 /PEG reaches impressively 11.34 mM −1  s −1 in a 0.5 T magnetic field, which is significantly higher than ordinary Mn(II)-based T 1 agents. In vivo magnetic resonance and PA imaging demonstrate that GO/MnWO 4 /PEG could serve as an efficient bimodal contrast agent to guide the cancer treatment. GO/MnWO 4 /PEG shows a high loading capacity for anticancer drug doxorubicin hydrochloride (DOX) by noncovalent forces, and the drug release could be triggered by lower pH value and external NIR light. Effective synergistic photothermo-chemotherapy has been performed in xenograft 4T1 tumor models after intravenous administration of GO/MnWO 4 /PEG/DOX. No obvious toxicity and side effect have been observed during in vivo treatment. These positive results suggest the promising application of GO/MnWO 4 /PEG as a versatile nanoplatform for multimodal imaging-guided cancer synergistic therapy. [ABSTRACT FROM AUTHOR]