The distribution characteristics of nanoparticles associated with cells are crucial to many applications, including magnetic hyperthermia, drug carriers, etc. To clarify the locations when nanoparticles enter the in vivo environments is a necessity. In this work, superparamagnetic iron oxide nanoparticles modified with polyethylene glycol (PEG-SPIONs) were prepared by high temperature thermal decomposition method, and then stereotaxic injections of PEG-SPIONs into the substantia nigra of Sprague-Dawley rats were performed. The distribution of nanoparticles in rat brain was observed by inductively coupled plasma emission spectrometer (ICP-OES) and transmission electron microscopy (TEM). It was found that the iron contents were higher in the olfactory bulb, temporal lobe, prefrontal cortex and thalamus after the injection of PEG-SPIONs for 24 h and 7 days, PEG-SPIONs were mostly distributed around the axonal membrane and dendritic membrane, and a small amount were distributed near the myelin membrane and mitochondrial membrane, which can be ascribed to the nature of PEG, the hydration size and Zeta potential of PEG-SPIONs. Along with their magnetocaloric effect the PEG-SPIONs have potential to act on the ion channels on the cell membrane under an alternating current magnetic field.

与细胞相关的纳米颗粒的分布特性对于许多应用至关重要，包括磁热疗，药物载体等。阐明纳米颗粒进入体内的位置环境是必须的。在这项工作中，通过高温热分解方法制备了用聚乙二醇修饰的超顺磁性氧化铁纳米粒子（PEG-SPIONs），然后将PEG-SPIONs立体定向注射到Sprague-Dawley大鼠的黑质中。通过电感耦合等离子体发射光谱仪（ICP-OES）和透射电子显微镜（TEM）观察纳米颗粒在大鼠脑中的分布。发现在注射PEG-SPIONs 24小时和7天后，嗅球，颞叶，前额叶皮层和丘脑中的铁含量较高，PEG-SPIONs主要分布在轴突膜和树突膜周围，并且少量分布在髓鞘膜和线粒体膜附近，这可以归因于PEG的性质，PEG-SPIONs的水合大小和Zeta电位。除了它们的磁热效应外，PEG-SPIONs还具有在交流磁场下作用于细胞膜上离子通道的潜力。