In vivo tomographic imaging with fluorescence and MRI using tumor-targeted dual-labeled nanoparticles

Abstract

Dual-modality imaging combines the complementary advantages of different modalities, and offers the prospect of improved preclinical research. The combination of fuorescence imaging and magnetic resonance imaging (MRI) provides cross-validated information and direct comparison between these modalities. Here, we report on the application of a novel tumor-targeted, dual-labeled nano particle (NP), utilizing iron oxide as the MRI contrast agent and near infrared (NIR) dye Cy5.5 as the fluorescent agent. Results of in vitro experiments verified the specificity of the NP to tumor cells. In vivo tumor targeting and uptake of the NPs in a mouse model were visualized by fluorescence and MR imaging collected at different time points. Quantitative analysis was carried out to evaluate the efficacy of MRI contrast enhancement. Furthermore, tomo graphic images were also acquired using both imaging modalities and cross-validated information of tumor location and size between these two modalities was revealed. The results demonstrate that the use of dual-labeled NPs can facilitate the dual-modal detection of tumors, information cross-validation, and direct comparison by combing fluorescence molecular tomography (FMT) and MRI. © 2014 Zhang et al.