基于活性氧响应与内耳前庭靶向的中药多成分智能化纳米递药系统及其用于梅尼埃病治疗

In the treatment of Meniere's disease (MD), how to achieve selective distribution in the pathogenic site and targeted release of traditional Chinese medicine (TCM) in order to simultaneously control the MD and minimize the side effects and hearing loss, has become an urgent problem to be solved. There exists an increase of reactive oxygen species (ROS) in the inner ear while MD happens. The high expression of the two receptors of cubilin and megalin is found in dark cells of the utricle and those flanking the crista ampullaris of the semicircular canals in the vestibular apparatus. On the basis of the pathological and structural characteristics, as well as our previous research findings, we will perform a novel and innovative study on an intelligent nanoparticulate drug delivery system loaded with TCM multiple components, which possesses ROS-responsive and vestibule-targeted dual functions. Chitosan, an oxidation-responsive material, will be used to formulate the nanoparticles (NPs). And the NPs will be modified by calcium ion, which is common ligand of both receptors co-localized in the vestibular apparatus. Acting as TCM partner, salviae miltiorrhizae and panax notoginseng are going to be employed as model drugs and their effective components including salvianolic acid and panax notoginseng saponins will be loaded in the NPs. The formulated nano-drug delivery system could obtain integrated achievements with in vivo orientated delivery and intelligent release. The encapsulated compound drugs could not only target the pathogenic site and yield multi-component synergistic therapeutic effect, but also automatically release from NPs in feedback ROS concentrations. We will variously examine oxidation-responsive release law, in vivo / in vitro transporting and targeting mechanism, biocompatibility and pharmacodynamics by means of in vitro experimental model, vestibular organotypic cultures and in vivo experiments with the cell, organism and animal level. The experimental results would show the influence of NPs properties on vestibular cellular uptake, membrane permeation and in vivo distribution and demonstrate the potential of the intelligent nanoparticulate drug delivery system serverved as TCM multicomponent delivery carrier via inner ear administration. In conclusion, this study will supply scientific information for developing design theory and methods of TCM preparation.

在梅尼埃病（MD）的治疗中，如何实现中药药效成分在病灶部位选择性地分布，并有针对性地释药，既能有效控制症状，又能尽量减少毒副作用、保护听力，已成为一个亟待解决的关键问题。为此，本项目在前期研究基础上，利用MD病发时活性氧（ROS）水平增加的病理特点以及前庭部位受体的介导作用，构建兼具ROS响应与内耳前庭靶向功能的中药多成分智能化纳米递药系统。该系统同时包载药对丹参-三七多种有效组分，以壳聚糖为氧化响应材料，采用前庭两种受体的共同配体钙离子修饰，不仅可将药物靶向输送至病灶部位，发挥中药多成分协同治疗作用，而且药物能根据ROS水平自动调节释放，从而实现体内定位递送与智能释药一体化。项目通过体外与体内试验，在细胞、组织和动物水平上多层次考察该递药系统的氧化响应释药机理、体内外转运与靶向分布机制、生物相容性及药效学规律，探讨其作为中药多成分内耳给药载体的潜力，为中药制剂的设计理论和方法提供参考。

梅尼埃病（MD）属中医“耳眩晕”范畴，为前庭系统功能障碍，严重影响了人们的工作和生活。内耳供血有限，而且血-内耳屏障严重阻碍了全身用药时中药药效成分进入内耳，限制了中药对MD的治疗效果。内耳局部给药能避开血-内耳屏障的阻碍，使药物直接进入内耳，但在MD的治疗中，如何实现中药药效成分在前庭选择性地分布，并有针对性地释药，既能有效控制症状，又能降低毒副作用、保护听力，已成为一个亟待解决的关键问题。本项目将现代医学理论和制剂新技术引入中药复方组分研究，利用MD的病理特点，以壳聚糖为氧化响应材料，同时包载药对丹参-三七多种有效成分，构建兼具ROS响应与内耳前庭靶向功能的中药多成分纳米递药系统，不仅可将药物靶向输送至病灶部位，发挥多成分协同治疗作用，而且能根据ROS水平自动调节释放，以实现体内定位递送与智能释药一体化。“质量源于设计”，本项目从剂型角度深入研究，制备了不同特性的壳聚糖纳米递药系统，并进行了结构表征、粒径分析与形态观察；制备的壳聚糖纳米系统具有ROS响应性能，且对H2O2诱导的细胞损伤有明显的保护作用；探索壳聚糖纳米系统经局部给药的转运通路、透膜机制及体内分布规律，首次发现了其经鼓室给药后能靶向分布于前庭，并揭示了进入前庭的机制为中耳—卵圆窗—前庭途径，从而为优化设计前庭给药系统，提高中药疗效奠定了基础。本项目设计和制备包载丹参-三七多组分的壳聚糖纳米系统，考察了经鼓室给药的转运分布特征，结果显示壳聚糖纳米载体能有效携载中药多成分至前庭，提高了局部生物利用度，延长了体内滞留时间。药效学和毒理学研究表明，该递药系统能防治MD，而且毒性低，对前庭和耳蜗组织的生物相容性良好。综上，本项目的研究结果不仅为前庭给药系统的设计提供理论指导，也为中药复方前庭制剂的研发提供技术支撑与参考，具有较高的学术价值和应用前景。