Biodistribution and Acute Toxicity of Intravenous Multifunctional 125I-Radiolabeled Fe3O4-Ag Heterodimer Nanoparticles in Mice
Fe3O4-Ag125I heterostructured radionuclide nanoparticles (NPs) have been developed as a novel type of dual-modality imaging agents for single-photon emission computerized tomography (SPECT) and magnetic resonance imaging (MRI). However, the biodistribution and toxicity of Fe3O4-Ag125I NPs remain largely unknown. Therefore, we investigated the biodistribution and biological action of Fe3O4-Ag125I NPs in mice by acute toxicity experiments (exposures over 7 days). The bioaccumulation of Fe3O4-Ag125I NPs was studied via in vivo experiments. The serum biochemistry and hematology were analyzed to reveal potential functional changes. The histopathological changes were observed by using an electron microscope. Biodistribution analysis revealed that Fe3O4-Ag125I NPs were mainly accumulated in the liver and spleen. The activities of liver enzymes (ALT and AST) were increased in Fe3O4-Ag125I NP-challenged groups compared with the control groups. Collectively, liver and spleen were the major target organs for accumulation of Fe3O4-Ag125I NPs. Damage of liver tissue was observed in the Fe3O4-Ag125I NP-challenged groups compared with the control groups. Further studies on surface coating of Fe3O4-Ag with targeted materials are highly necessary for safe medical applications of Fe3O4-AgNPs as dual-modality imaging agents.