双重介导的中药藤黄酸智能响应纳米粒定向干预肝癌细胞凋亡作用研究

Liver cancer is one of the common cancers in China, which is a serious threat to human health. Mitochondria organelles are closely related to cell apoptosis. The mitochondrial pathway regulates the apoptosis of tumor cells is a new way for many researchers to explore the treatment of liver cancer. Gambogic acid (GBA), an active ingredient of traditional Chinese medicine, which can achieve the therapeutic effect of liver cancer by promoting cell apoptosis molecular mechanism. However, the clinical application is limited by its poor stability and non-specific distribution in vivo. Therefore, it is urgent necessary to develop suitable target drug carriers for GBA specific delivery to mitochondria. It is of great significance to develop the new formulations of Chinese medicine against liver cancer and promote the modernization of traditional Chinese medicine (TCM). In this project, the biological material methods are used to design and synthesize the reduction-sensitive drug carrier targeting to hepatocellular carcinoma cells, as well as the mitochondrial-targeting GBA pro-drug. Then, smart responsive GBA drug delivery systems with dual targeting of hepatocellular carcinoma cells and mitochondria are constructed and evaluated. Molecular biology techniques are used to study the apoptosis related effects of drug loaded nanoparticles on cell level and animal model. The purpose of this study is elucidated the cell apoptosis effects induced by dual-targeted and smart responsive GBA nanoparticles from multiple perspectives, which might be a potential strategy for research and development of new drug used in the treatment of liver cancer.

肝癌是我国常见癌症之一，严重威胁到人类生命健康。线粒体是与细胞凋亡密切相关的细胞器，以线粒体途径调控肿瘤细胞凋亡是众多研究者致力探索肝癌治疗方法的新思路。藤黄酸(GBA)作为一种可通过促细胞凋亡分子机制实现肝癌治疗的中药活性成分，因稳定性差、体内非特异性分布等缺点限制其临床应用。因此，寻找合适的靶向药物载体用于GBA在线粒体的特异性递送，对中药新型抗肝癌药物的研发、促进中医药现代化发展具有重要意义。本项目利用生物材料学方法，设计合成肝癌细胞靶向介导的还原敏感药物载体，以及针对线粒体特异性靶向的GBA前药，构建具有肝癌细胞及其线粒体双重靶向功能的智能响应GBA纳米递药体系并对其表征评价，结合分子生物学技术深入研究递药体系在细胞水平、动物模型上的生物转运及促肝癌细胞凋亡相关药效。本项目从多环节、多角度阐明双重靶向智能响应GBA纳米粒促肝癌细胞凋亡作用，为肝癌治疗的研究奠定良好的理论和实验基础。

肝癌作为我国的高发癌症之一，对人们的生命健康产生严重威胁，目前对于癌症的治疗仍旧以化学药物治疗、手术治疗为主。为了达到预期治疗效果，降低治疗过程中所带来的毒副作用，如何通过设计、开发多功能的药物载体，更有效地将药物递送至靶向部位，已然成为研究者关注的重点。. 本项目基于肿瘤微环境特异性，设计、合成了以甘草次酸（GA）修饰的肝癌细胞靶向介导的肿瘤环境敏感药物载体，并构建其智能响应给药系统，开展相应抗肿瘤活性研究。研究发现，以双硫键连接合成的藤磺酸二聚体（GSG）前药，其自身可实现“纳米化”，形成纳米尺寸溶液，且基于该二聚体形式构建的还原敏感胶束GA-PEG-SS-PCL/GSG具有较好的载药量及稳定性，推测该胶束的良好性能可能与藤黄酸的二聚体形式有关。体外药效学发现藤磺酸二聚体前药对肝癌细胞HepG2具有一定的细胞毒性，且GA-PEG-SS-PCL载体在一定程度上也可以促进HepG2细胞的摄取。此外，为了研究GA的肝癌靶向性以及肿瘤微环境智能响应药物递送体系的构建，本项目进一步设计了一种由缩醛键连接的F68-acetal-PCL酸敏感聚合物和Pluronic F68-GA聚合物共同构建的混合胶束，使其既具有肝癌靶向性，同时又具有肿瘤微环境响应释药特性。体外药效学研究发现，载药混合胶束具有更好可明显抑制肝癌细胞增殖，促进细胞摄取、凋亡，表现出更高的ROS水平，能使药物更好地发挥其抗肝癌作用。通过本项目的实施为开发中药智能响应给药系统提供了一定研究基础，同时也为如何提升制剂的载药量、稳定性提供新的思路与参考。