Cu-Doped Extremely Small Iron Oxide Nanoparticles with Large Longitudinal Relaxivity: One-Pot Synthesis and in Vivo Targeted Molecular Imaging

Synthesizing iron oxide nanoparticles for positive contrast in magnetic resonance imaging is the most promising approach to bring this nanomaterial back to the clinical field. The success of this approach depends on several aspects: the longitudinal relaxivity values, the complexity of the synthetic protocol, and the reproducibility of the synthesis. Here, we show our latest results on this goal. We have studied the effect of Cu doping on the physicochemical, magnetic, and relaxometric properties of iron oxide nanoparticles designed to provide positive contrast in magnetic resonance imaging. We have used a one-step, 10 min synthesis to produce nanoparticles with excellent colloidal stability. We have synthesized three different Cu-doped iron oxide nanoparticles showing modest to very large longitudinal relaxivity values. Finally, we have demonstrated the in vivo use of these kinds of nanoparticles both in angiography and targeted molecular imaging. ©
This study was supported by grants from the Spanish Ministry for Economy and Competitiveness (MEyC) (SAF2016-79593-P, MAT2017-88148-R, and SAF2017-84494-C2-R), Comunidad de Madrid (S2017/BMD-3875), and Instituto de Salud Carlos III (DTS16/00059). L.G. received financial support from the Ramońy Cajal subprogram (RYC-2014-15512). J.R.-C. acknowledges funding from the Programa Red Guipuzcoana de Ciencia, Tecnología e Información (2018-CIEN-000058-01). I.F.-B. thanks Comunidad de Madrid (B2017/BMD-3875). This work was performed under the Maria de Maeztu Units of Excellence Program from the Spanish State Research Agency (Grant No. MDM-2017-0720)