Institute of Material Science of Madrid, ICMM-CSIC, Sor Juana Inés de la Cruz 3, 28049 Madrid, Spain.
School of Chemistry and Biochemistry, Georgia Institute of Technology, 315 Ferst Drive NW, Atlanta, GA 30332, USA.
Contrast Media Mol Imaging. 2017 Dec 4;2017:8902424. doi: 10.1155/2017/8902424. eCollection 2017.
Uniform iron oxide magnetic nanoparticles have been synthesized using a microwave assisted synthesis method in organic media and their colloidal, magnetic, and relaxometric properties have been analyzed after its transference to water and compared with those nanoparticles prepared by thermal decomposition in organic media. The novelty of this synthesis relies on the use of a solid iron oleate as precursor, which assures the reproducibility and scalability of the synthesis, and the microwave heating that resulted in being faster and more efficient than traditional heating methods, and therefore it has a great potential for nanoparticle industrial production. The effect of different experimental conditions such as the solvent, precursor, and surfactant concentration and reaction time as well as the transference to water is analyzed and optimized to obtain magnetic iron oxide nanoparticles with sizes between 8 and 15 nm and finally colloids suitable for their use as contrast agents on Magnetic Resonance Imaging (MRI). The relaxivity values normalized to the square of the saturation magnetization were shown to be constant and independent of the particle size, which means that the saturation magnetization is the main parameter controlling the efficiency of these magnetic nanoparticles as MRI -contrast agents.
采用微波辅助法在有机溶剂中合成了单分散的磁性氧化铁纳米颗粒，并对其在转移到水中后的胶体、磁性和弛豫性能进行了分析，同时将其与在有机溶剂中通过热分解制备的纳米颗粒进行了比较。该合成方法的新颖之处在于使用了固体油酸铁作为前体，这保证了合成的可重复性和可扩展性，并且微波加热比传统加热方法更快、更高效，因此在纳米颗粒的工业生产中具有很大的潜力。分析和优化了不同实验条件（如溶剂、前体和表面活性剂浓度以及反应时间）以及转移到水中的条件，以获得粒径在 8 至 15nm 之间的磁性氧化铁纳米颗粒，并最终得到适合用作磁共振成像（MRI）造影剂的胶体。结果表明，弛豫率与饱和磁化强度的平方之比是恒定的，与粒径无关，这意味着饱和磁化强度是控制这些磁性纳米颗粒作为 MRI 造影剂效率的主要参数。
