Enhanced dual (T1-and T2-weighted) MRI contrast by single core iron oxide nanoparticles

A. Lavin, B. Thapa, Gerardo Morell, Brad R. Weiner
Universidad de Puerto Rico,
United States

Keywords: MRI, contrast agent, relaxivity, iron oxide nanoparticles

Summary:

Conventional T1- or T2-weighted single mode contrast-enhanced magnetic resonance imaging (MRI) may produce false results. Thereby, there is a need to develop dual contrast agents, T1- and T2-weighted, for more accurate MRI imaging. The dual contrast agents should possess high magnetic resonance (MR) relaxivities, targeted tumor linking, and minimum recognition by the immune system. Here, we report a nitrodopamine-PEG grafted single core iron oxide nanoparticle (ND-PEG-tNCIOs)-based platform capable of producing marked dual contrasts in MRI with enhanced longitudinal and transverse relaxivities (r1 and r2). Our results show that ND-PEG-tNCIOs exhibit r1 and r2 values of 32 and 791 mM−1s−1, respectively. Furthermore, the ND-PEGtNCIOs show excellent colloidal stability in physiological buffers and higher cellular internalization in leukemia (CCRF-CEM) than in phagocytic (CRL-9855) cells, indicating the immune evasive capability of the nanoparticles. These findings suggest that tNCIOs are strong candidate for dual contrast MRI imaging suitable for preclinical applications.