抗CD123修饰的纳米粒跨血－神经屏障治疗白血病周围神经浸润的机制研究

白血病是累及多系统的全身性恶性肿瘤，可以浸润到周围神经系统。由于血－神经屏障的存在，常规静脉和鞘内化疗对周围神经实质内的瘤细胞作用有限。已知共聚物包囊的磁性纳米粒，具有携带治疗剂通过血脑屏障治疗中枢神经系统肿瘤的能力，但其通过屏障的机制未完全清楚。血－神经屏障结构与功能与血脑屏障相似。本项目拟用协同沉淀法合成壳聚糖－聚乙二醇包囊的氧化铁纳米粒，用白血病治疗性抗体抗CD123修饰纳米粒。用共聚焦显微镜、流式细胞分析和铁含量测定等方法，证实纳米粒透过血－神经屏障体外模型的能力。用内吞途径抑制剂、途径内蛋白基因敲除、途径内蛋白的活性测定等方法，初步确定纳米粒跨血－神经屏障的机制。用细胞生长活性测定、磁共振成像、病理免疫组化等手段评价纳米粒透过屏障后对白血病细胞的特异性抑瘤作用。此研究对纳米载体更有效地穿透血－神经屏障治疗周围神经系统疾病有重要意义。

Leukemia is systemic malignant tumor involving multiple systems including peripheral nervous system. Due to blood-nerve barrier, conventional systemic and intrathecal chemotherapy has limited effect on leukemia cells infiltrated in peripheral nerve system parenchyma. It is well known that copolymer coated magnetic nanoparticles carrying therapeutic agents can treat central nervous system tumors across blood-brain barrier. But its mechanism is not fully clear. Blood-nerve barrier is similar to blood-brain barrier on both structure and function. This project is about to synthesize chitosan-polyethylene glycol copolymer coated iron oxide nanoparticles by coprecipitation method. The nanoparticles will be modified by anti-CD123, a therapeutic antibody against leukemia. Confocal microscopy, flow cytometry and iron content determination will be used to confirm the blood-nerve barrier permeability of nanoparticles in vitro. Endocytosis pathway inhibitor, involved protein knockout, and involved protein activity determination will be used to confirm the preliminary mechanism of nanoparticles transcytosis across blood-nerve barrier. Cell growth activity determination, magnetic resonance imaging, and immunohistochemical pathology will be used to evaluate tumor suppression effect on leukemia cell of the nanoparticles across blood-nerve barrier.The result of this research has important significance on treatment of peripheral nervous system diseases by nanometer carrier across blood-nerve barrier more effectively.