基于凝胶夹层调控的“三明治式”纳米胶束序贯递送中药黄酮类化合物与化疗药物治疗耐药肿瘤及逆转机制研究

Malignant tumor is a serious threat to human health，currently multidrug resistance (MDR) become a bottleneck in effective cancer treatment. Traditional Chinese medicine flavonoids and chemotherapeutic drugs have a synergistic anti-MDR tumor effect, but how to achieve the optimal therapeutic effect is still a core scientific problem. Our previous studies have found that delivery mode can affect the anti-MDR tumor effect. Sequential delivery of flavonoids and chemotherapeutic drugs can inhibit the growth of drug-resistant cells effectively. Based on the above mentioned, the hypothesis of this project is that the sequential delivery system of traditional Chinese medicine flavonoids and chemotherapeutic drugs through “sandwich” nano-targeted drug delivery system with “sandwich-gel sandwich-target coating” will effectively exert their combined effect for improved MDR tumor treatment. In the basis of the optimization of the sequential delivery scheme by the in vitro and in vivo pharmacodynamic models, we will establish a novel nano-targeted drug delivery system to confirm its therapeutic effect on MDR tumors, and explore its MDR reversal mechanisms from two aspects: regulation of energy supply or metabolism and ABC efflux pump. This project will provide new ideas and methods for traditional Chinese medicine to address the issue of multidrug resistance in tumor.

恶性肿瘤严重威胁人类健康，多药耐药（multidrug resistance, MDR）日益成为其有效治疗的瓶颈问题。中药黄酮类化合物与化疗药物具有协同抗MDR肿瘤作用，但如何达到最佳治疗效果，仍是亟需解决的核心科学问题。我们前期研究发现，递药方式会影响抗MDR肿瘤作用的发挥，序贯式递送黄酮类化合物与化疗药物能有效抑制耐药细胞生长。基于以上，本项目提出中药黄酮类化合物与化疗药物可以通过“内核-凝胶夹层-靶向包被层”的“三明治式”纳米靶向递药系统的序贯递送方式，有效地发挥它们联合治疗MDR肿瘤作用的假说。拟在运用体内外药效模型优化序贯递送方案的基础上，构建该纳米靶向递药体系，确证其MDR肿瘤治疗作用后，从调控能量供应与代谢、ABC外排泵两个角度探讨逆转机制。以期为中医药解决肿瘤多药耐药问题提供新的思路和方法借鉴。

恶性肿瘤严重威胁人类健康，多药耐药（multidrug resistance，MDR）日益成为其有效治疗的瓶颈问题。中药黄酮类化合物与化疗药物具有协同抗MDR肿瘤作用，本项目采用体内外药效实验确定两药序贯作用方案，并从肿瘤部位自身特点出发，利用被动/主动靶向、微环境响应等原理设计一种内核-凝胶夹层-靶向包被层的 “三明治式”纳米靶向递药系统，使两药联合抗耐药肿瘤的效应最大化。构建了乳腺癌耐药细胞模型，具有多药耐药性，明确其细胞倍增时间、细胞周期、外排蛋白表达等生物学特征，筛选出具有化疗药物增敏作用的中药黄酮成分。两药较优的序贯给药方案为：中药黄酮成分与化疗药物的作用时间比为1︰2、作用剂量比为1︰1~1︰2。选用聚乙烯亚胺（PEI）、生育酚琥珀酸酯（TOS）、透明质酸（HA）为载体材料，中药黄酮成分槲皮素（QU）与化疗药物紫杉醇（PTX）为模型药物，构建装载 PTX的 PEI-TOS 胶束为内核、二硫代甘醇酸（SS）交联PEI引发形成凝胶夹层、HA-酸敏键-QU共聚物包裹在外形成靶向包被层的“三明治式”纳米靶向递药系统（PTX/PTS/HQ纳米胶束）。所得纳米胶束呈类球形粒子，分散均匀；粒径为~185 nm，电位在-20 mV左右；紫杉醇、槲皮素的载药量分别为9.7%-10.5%和1.6%-1.8%。此胶束能够响应微酸性环境优先释放槲皮素，响应高还原、低pH值环境快速且完全地释放紫杉醇，实现两药的序贯式释放；稳定性与血液相容性良好；具有较好的体内外肿瘤靶向性与安全性；体内外抗肿瘤作用较强，对荷瘤裸鼠的抑瘤率为49.4%，是市售制剂组的1.7倍（p < 0.05）。PTX/PTS/HQ纳米胶束抗耐药肿瘤机制包括：（1）实现溶酶体逃逸、降低外排蛋白P-gp的表达，使细胞内维持较高的药物浓度；（2）抑制葡萄糖摄取以调控乳腺癌细胞的能量代谢；（3）破坏形态完整性、降低膜电位、诱导ROS产生等造成线粒体功能紊乱。本项目不仅为克服肿瘤耐药问题提供方法与思路借鉴，也为推动中医药在抗肿瘤领域的应用提供支持。