Localizing nanoparticles on or near cell membranes in vivo remains a big challenge. We present a cell membrane targeting complex based on chondroitin sulfate (CS)-conjugated superparamagnetic iron oxide nanoparticles (CS-SPIONs). After SPIONs were injected into the substantia nigra of rats, the subcellular distributions of SPIONs with and without CS modification have been evaluated by transmission electron microscopy (TEM) analysis. CS-SPIONs exhibited low toxicity and low endocytosis and were highly distributed in the extracellular spaces nearing neuronal cell bodies and synapses. This can be attributed to the nature of CS, one of the main components of perineuronal nets with the tendency to surround neuronal cell bodies, dendrites, and synapses. It is expected that CS-SPIONs have a great potential for therapies requiring targeting of or approach to cell membranes.

中文翻译：

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用硫酸软骨素的表面改性将纳米颗粒靶向黑质中的神经元细胞膜。

在体内将纳米颗粒定位在细胞膜上或附近仍然是一个巨大的挑战。我们提出了基于硫酸软骨素（CS）-共轭超顺磁性氧化铁纳米粒子（CS-SPIONs）的细胞膜靶向复合物。将SPIONs注入大鼠黑质后，通过透射电子显微镜（TEM）分析评估了具有和不具有CS修饰的SPIONs的亚细胞分布。CS-SPIONs表现出低毒性和低内吞作用，并高度分布在靠近神经元细胞体和突触的细胞外空间。这可以归因于CS的性质，CS是神经周围神经网络的主要组成部分之一，具有围绕神经元细胞体，树突和突触的趋势。