基于“薄荷药引”莪术组分多功能纳米载体的构建及协同靶向肿瘤及干细胞机理研究

Cancer stem cells (CSC) with drug-resistance, are the foundation of tumor growth and progression, maintenance, metastasis and recurrence. CD44 is highly expressed in CSC and other cacncer cells, showinging its functions as an importaint target for killing the cells. Simultaniously, the tumor microenvironment has slightly lower pH and redox properties. Components of Curcuma Zedoary has two effective components β-elemene and curcumin, both of them have lower bioavailability. Herein, in this project, to solve the problem of disadvantage of single cancer therapy and lack of specificity of CSC treatment, we use dual pH and redox sensitive oHA nano-carriers based on the Traditional Chinese Medicine menthone in the leading mint and curcumin to co-deliver curcumin and β-elemene with CD44 receptor as the target. After endocytosis, the nano-carriers will release the encapsuled drugs under the slightly acidic condition of tumor rapidly with the degration of micellar hydrophobic ketal group. Then, endosomal membrane will be distroyed by the neutral ketone and alcohol degradation products of the leading mint. Other nano-carriers will enter into the cytoplasm and degrade with the breakage of disulfide linkage under the redox GSH. Both the encapsuled drugs and curcumin on the carriers will escape from endosome to cytoplasm with good stability and produce efficacy and reduce side effects. The both curcumin can suppress the CSC proliferation and metastasis and can kill the cancer and CSC together with the β-elemene reducing the multi-resistant and get the satisfying multifunctional synergistic effect of tumor therapy. This project is to systematically study its anti-tumor mechanism from the level of cells and whole animals.The research project will provide theoretical and experimental basis of multifunctional targeted nano-carrier drug delivery system as a new strategy and theory mechanism for the cancer therapy of Chinese Medicine with higher efficiency and lower toxicity.

肿瘤干细胞（CSC）是肿瘤发生和复发的根源（耐药）；CD44受体在肿瘤和CSC高表达，也是杀灭CSC的重要靶点；肿瘤细胞微环境具有低pH和还原特性；莪术组分姜黄素和β-榄香烯，生物利用度低。本项目针对中药肿瘤治疗策略单一和CSC特异性治疗缺乏的弊端，利用薄荷有效成分薄荷酮为“药引”和姜黄素设计了一种新型基于CD44受体靶向的含有双重pH敏感缩酮和还原敏感二硫键的纳米载体，包载姜黄素和 β-榄香烯。当载体靶向到肿瘤及CSC后，进入内涵体，在内涵体低pH微环境下薄荷缩酮裂解，“引导”内涵体膜破裂，实现内涵体逃逸和药物释放，同时部分未解离载体进入细胞质后，在谷胱甘肽还原作用下裂解二硫键，“引导”载体完全解离，解离的姜黄素及包裹的姜黄素抑制肿瘤干细胞转移，协同β-榄香烯共同杀伤肿瘤细胞和CSC。本项目将从细胞及整体动物水平进行系统研究，为探索“高效低毒”中药抗肿瘤新策略提供理论基础和实验依据。

肿瘤干细胞（CSC）是肿瘤发生和复发的根源（耐药）；CD44受体在肿瘤和CSC高表达，也是杀灭CSC的重要靶点；肿瘤细胞微环境具有低pH和还原特性；莪术组分姜黄素和β-榄香烯，生物利用度低。本项目针对中药肿瘤治疗策略单一和CSC特异性治疗缺乏的弊端，利用薄荷有效成分薄荷酮为“药引”和姜黄素设计了一种新型基于CD44受体靶向的含有双重pH敏感缩酮和还原敏感二硫键的纳米载体，包载姜黄素和 β-榄香烯。当载体靶向到肿瘤及CSC后，进入内涵体，在内涵体低pH微环境下薄荷缩酮裂解，“引导”内涵体膜破裂，实现内涵体逃逸和药物释放，同时部分未解离载体进入细胞质后，在谷胱甘肽还原作用下裂解二硫键，“引导”载体完全解离，解离的姜黄素及包裹的姜黄素抑制肿瘤干细胞转移，协同β-榄香烯共同杀伤肿瘤细胞和CSC。. 制备的纳米载体，粒径为102.5±4.6 nm，包封率为52.9±2.6 % 。体外pH/氧化还原敏感实验证明了有一定的pH和氧化还原敏感特性，达到了预期研究目标，在pH7.4条件下稳定，基本不释放，但在低pH及氧化还原敏感环境下释放加速，两天内超过80%。细胞实验证明具有更低的细胞毒性，在低pH和还原环境具有更好的细胞摄取现象，表明了其敏感特性。体内动物组织分布及药效学证明，纳米载体具有明显缓释作用，在24h仍能监测到其荧光信号，而对照组则在8h之后没有监测到。药效学及病理实验验证了修饰纳米载体具有更强的抗肿瘤效果。另外，为了更好的体现该载体的靶向性，增加了线粒体靶向、骨靶向等基团的修饰，提高了肿瘤的靶向性及在肿瘤及干细胞微环境中响应特性，发表多篇相关SCI论文。为探索“高效低毒”中药抗肿瘤新策略提供理论基础和实验依据。