Biomimetic magnetofluorescent ferritin nanoclusters for magnetic resonance and fluorescence-dual modal imaging and targeted tumor therapy.

Multiple imaging by combining magnetic resonance (MR) and fluorescence imaging into a single nanosystem displays distinctive merits, which is desirable for precise in vivo imaging. In this work, we proposed a new tumor-targeting dual-modal diagnosis strategy by designing and fabricating a biocompatible nano-erythrocyte and successfully delivering it into in vivo tumors. The novel nano-contrast agent (CMR) was prepared by encapsulating human heavy-chain ferritin (HFn) nanoparticles with Cy5.5 binding and mineralized iron oxide nanoparticles (Fe3O4 NPs) into erythrocyte membranes (RBCs). We demonstrated that the as-prepared CMR displayed excellent biocompatibility with low hepatotoxicity and long blood circulation time. More importantly, by functionalizing the CMR with different types of targeting moieties, the nanosystem could precisely target both subcutaneous and orthotopic tumors, and exhibited excellent MR and fluorescence dual-model imaging ability. Moreover, we demonstrated that the CMR was able to modulate the tumor microenvironment to achieve an efficient antitumor effect.