Superparamagnetic iron oxide nanoparticles (SPION) are extensively used for magnetic resonance imaging (MRI) and magnetic particle imaging (MPI), as well as for magnetic fluid hyperthermia (MFH). We here describe a sequential centrifugation protocol to obtain SPION with well-defined sizes from a polydisperse SPION starting formulation, synthesized using the routinely employed co-precipitation technique. Transmission electron microscopy, dynamic light scattering and nanoparticle tracking analyses show that the SPION fractions obtained upon size-isolation are well-defined and almost monodisperse. MRI, MPI and MFH analyses demonstrate improved imaging and hyperthermia performance for size-isolated SPION as compared to the polydisperse starting mixture, as well as to commercial and clinically used iron oxide nanoparticle formulations, such as Resovist® and Sinerem®. The size-isolation protocol presented here may help to identify SPION with optimal properties for diagnostic, therapeutic and theranostic applications.

中文翻译：

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超顺磁性氧化铁纳米粒子的尺寸隔离可改善MRI，MPI和热疗性能。

超顺磁性氧化铁纳米粒子（SPION）已广泛用于磁共振成像（MRI）和磁性粒子成像（MPI），以及磁流体热疗（MFH）。我们在这里描述了一种顺序离心方案，以从多分散SPION起始配方中获得具有明确定义大小的SPION，该起始配方是使用常规采用的共沉淀技术合成的。透射电子显微镜，动态光散射和纳米粒子跟踪分析表明，大小分离后得到的SPION组分定义明确，几乎单分散。MRI，MPI和MFH分析表明，与多分散起始混合物以及市售和临床使用的氧化铁纳米颗粒制剂相比，尺寸分离的SPION的成像和热疗性能得到改善，例如Resovist®和Sinerem®。此处介绍的大小隔离协议可能有助于识别具有诊断，治疗和治疗诊断应用最佳性质的SPION。