壳聚糖表面修饰的芫花立方液晶纳米透皮给药系统抗黑色素瘤及其靶向机制研究

Melanoma, a common skin malignant tumor, attracts extensive attention due to its increasing incidence and mortality rate. Lilac daphne, a traditional Chinese medicine with daphne diterpene esters as its effective part, was applied for the treatment of melanoma historically and clinically. However, the effective part could not fully perform its effectiveness due to the lack of efficient drug delivery system to delivery it into the tumor site. In the current project, a cubic liquid crystalline nanoparticles surficial-modified by chitosan (chito-cubosomes) was designed to transdermal delivery of daphne diterpene esters for the treatment of such skin tumor. Development and optimization of formulation and preparation process of effective part loaded chito-cubosomes, elucidation of targeting delivery mechanism of transdermal chito-cubosomes, and the evaluation of its anti-tumor activities will be carried out, in order to (1) improve the anti-melanoma efficacy and decrease the adverse effects of Lilac daphne, and (2) provide theoretical and experimental basis of an advanced pharmaceutical technology for its application in transdermal targeting delivery of Chinese medicine in the treatment of tumors.

黑色素瘤是一种常见于皮肤的恶性肿瘤，其日渐上升的发病率及高致死率受到医药学界的广泛关注。芫花是经过实验研究及临床确证的抗黑色素瘤常用中药，其抗肿瘤活性物质基础为芫花二萜酯类有效部位。但受制剂技术限制，目前缺乏有效手段将该活性部位有效递送至肿瘤组织，从而无法更好地发挥抗肿瘤活性。根据黑色素瘤的发病特点为多发于皮肤，项目申报者创新性地提出以立方液晶纳米粒作为药物载体，通过表面修饰正电性壳聚糖实现肿瘤靶向性的经皮给药制剂设计理念。项目拟通过制剂制备方法的研究、经皮肿瘤靶向机理的阐明、制剂抗肿瘤活性评价等内容对上述设计理念进行深入探讨，拟通过本项目研究（1）解决现有芫花抗肿瘤制剂缺陷，进一步提高芫花抗黑色素瘤效果、降低毒副作用；（2）阐明壳聚糖修饰液晶纳米粒经皮递释系统的肿瘤靶向机制，为这一前沿制剂技术在中药经皮肿瘤靶向给药系统中的深入研究和开发提供理论依据。

黑色素瘤多发于皮肤，近年来发病率与死亡率逐年升高，早期诊断和治疗极其重要。经药理和临床研究表明瑞香属植物芫花中的芫花二萜酯类化合物可有效抑制黑色素瘤增殖。目前仍缺乏有效的制剂方法将有效部位靶向递送到肿瘤组织，限制了其进一步的开发。本项目以立方液晶纳米粒作为药物载体，通过表面修饰正电性壳聚糖实现肿瘤靶向性的经皮给药制剂。采用回流提取法获得芫花二萜酯类有效部位，将其载入GMO液晶材料，并通过高压均质法联合交联反应制备得到载药的壳聚糖修饰的立方液晶纳米粒（chito-cubosomes），粒径约为105nm，zeta电位约为-21.6mV，内部结构呈现P面体心立方晶格（Im3m）。与普通液晶纳米粒（cubosomes）相比，具有缓释作用，符合Korsmeyer-Peppas释药模型。刺激性试验表明多次给药后chito-cubosomes对皮肤无刺激性。大鼠体内药代动力学研究表明与口服二萜酯类有效部位混悬液相比，经皮给予cubosomes的达峰时间及半衰期明显延长，而经皮给予chito-cubosomes表现出更为明显的缓释特征，血药浓度维持时间显著提高；经皮透过药动学研究表明药物在角质层的渗透量随时间增加，与普通溶液组相比，给予chito-cubosomes后主要有效成分YHC与YHD在在真皮层具有更高的药物浓度，药物浓度达峰时间最长，可在皮肤的角质层内形成药物贮库，从而可达到缓释的作用。黑色素瘤小鼠模型表明，经皮给予chito-cubosomes可有效抑制黑色素瘤的生长，抑制率显著高于口服组及cubosomes组。经过细胞摄取动力学试验发现chito-cubosomes能有效地被A375黑色素瘤细胞摄取，且显著优于cubosomes组和溶液组，这可能是由于表面修饰的阳离子壳聚糖具有的生物粘附性及经皮渗透性相关。项目通过制剂制备方法的研究、经皮肿瘤靶向机理的阐明、制剂抗肿瘤活性评价等内容解决了现有芫花抗肿瘤制剂缺陷，进一步提高芫花抗黑色素瘤效果、降低毒副作用，为这一前沿制剂技术在中药经皮肿瘤靶向给药系统中的深入研究和开发提供理论依据。