神经毒素二氧化硅脂质囊纳米粒"连环-分子"靶向PAG递药系统研究

Neurotoxin, the main composition of the TCM of Naja naja atra's snake venom , is a promising drug for clinical treatment of cancer pain. However the present application of Neurotoxin is limited due to its high toxicity, ineffective and incapability of crossing the blood-brain barrier (BBB). Rely on our previous work, this study intends to solve these problems by combining the "guiding medicine" of TCM, and using the latest inorganic Nano-materials with multi-path active targeting technology in constructing a "sequential-molecule" targeting periaqueductal gray (PAG) drug delivery system(DDS). We choose LipidParticle (LP-MSN) based on mesoporous silica nanoparticles（MSN） as carrier materials. Then, the outer surface of LP-MSN will be encapsulated with borneolum to increase the accumulation in brain and PEGylation to decrease the uptaking of RES. Furthermore, in order to across the BBB, we decorate the surface of LP with Angiopep-2, a brain targeting ligands. Finally, we modified the MSN with choline to increase the concentration of NT in brain because of the acetylcholine transporter highly expressed over the PAG. On the other hand, the characteristics of "sequential-molecule" targeting of the DDS are investigated on the BBB model in vitro and rats using in vivo microdialysis and whole-body fluorescene imaging technologies. Finally, the transport mechanism of the DDS is studied in vitro and in vivo experiments. Our research not only provides new ideas for increasing the efficacy of Neurotoxin , but also possesses great reference meaning in the study of poisonous TCM or protein polypeptide drugs carrier systems.

针对神经毒素毒性大、难以透过血脑屏障、起效慢的难题，在前期研究的基础上（国家自然科学基金NO.30371781、NO.30772793），本项目拟结合中药"引药上行"理论，应用多重靶向技术与新型无机纳米材料，构建具有"连环-分子"靶向特性的PAG递药系统。以"核-囊"结构的介孔二氧化硅脂质囊纳米粒为载体，通过冰片包裹、Angiopep-2修饰脂质"囊"表面，胆碱修饰硅纳米粒"核"，实现引药上行至脑、多途径多重靶向机制跨越BBB，最终以胆碱转运体介导实现PAG分子靶向，使神经毒素发挥速效、高效、持久的镇痛作用。同时以微透析在线动态分析技术为核心，结合活体荧光示踪、扫描透射电子显微镜等技术构建靶向研究平台，综合评价该递药系统的靶向性，探究其转运机制。本项目的完成将为实现神经毒素"增效减毒"的目的提供新的研究策略，同时为构建有毒中药动物药、蛋白多肽类药物脑靶向递药系统提供新思路和新方法。

针对神经毒素毒性大、难以透过血脑屏障、起效慢的难题，通过制备Angiopep-2修饰的介孔二氧化硅脂质囊纳米粒（ANG-MSN-LP），运载镇痛药物神经毒素（NT），以期达到脑靶向递药和提高其镇痛治疗效果；同时，建立了高选择性、高敏感性的神经毒素体内外分析方法，将其应用于NT制剂的测定及评价。通过对该递药系统的研究，为实现神经毒素“增效减毒”的目的提供新的研究策略，同时为蛋白多肽类药物脑靶向制剂的设计、开发与评价提供重要的理论和实践参考。