Water-Soluble Spinel Ferrites by a Modified Polyol Process as Contrast Agents in MRI

摘要

Magnetic nanoparticles have recently been very attractive for biomedical applications. In this study, we have synthesized ferrite nanoparticles for application as contrast agents in MRI experiments. Fe_3O_4 and MnFe_2O_4 spinel ferrites with a mean size of 11-12 nm, were prepared by a modified polyol route in commercially available polyethylene glycol with molecular weight 600 (PEG-600). The reaction takes place in the presence of water soluble and non-toxic triblock copolymer known as Pluronic~R F-127 (PEO_(100)-PPO_(65)-PEO_(100)). The nanoparticles have saturation magnetization values of 52 and 68 emu/g for MnFe_2O_4 and Fe_3O_4, respectively. Both the Fe_3O_4 and MnFe_2O_4 nanoparticles make stable solutions in water known as ferrofluids. Preliminary data demonstrated the capability of these nanoparticles to induce imaging contrast in T_2 weighted MRI experiments, making these materials suitable for biomedical applications such as medical MRI.