Magnetite and Iodine-Containing Nano-Emulsion as Dual Modal Contrast Agent for X-Ray/MR Imaging.

Non-invasive diagnostic by imaging combined with contrast agent (CA) is by now the most used technique to get an insight inside human bodies. X-ray and magnetic resonance imaging (MRI) are widely used technologies providing complementary results. Nowadays, it seems clear that bimodal CAs could be an emerging approach to increase the patient compliance, accessing the different imaging modalities with a single CA injection. Owing to versatile designs, targeting properties and high payload capacity, nanocarriers are considered as a viable solution to reach this goal. In this study, we investigated efficient superparamagnetic iron oxide nanoparticles (SPIONs) loaded iodinated nano-emulsions (NEs) as dual modal injectable CAs for X-ray imaging and MRI. The strength of this new CA lies not only in its dual modal contrasting properties and biocompatibility, but also in the simplicity of the nanoparticulate assembling: iodinated oily core was synthesized by triiodo-benzene group grafting on vitamin E (41.7% of iodine) via esterification and SPIONs were produced by thermal decomposition during 2h, 4h and 6h to generate SPIONs with different morphologies and magnetic properties. SPIONs with most anisotropic shape and characterized by the highest r2/r1 ratio once encapsulated into iodinated NE were used for animal experimentation. The in vivo investigation showed an excellent contrast modification due to the presence of the selected NEs, for both imaging technics explored, i.e. MRI and X-ray imaging. This work provides the description and in vivo application of a simple and efficient nanoparticulate system capable of enhancing contrast for both preclinical imaging modalities, MRI and CT.