麝香酮和适配体级联修饰多烯紫杉醇脑靶向递送系统抗胶质瘤作用及机制的研究

The treatment of glioma is still one of the most difficult challenges in the field of cancer. Due to the presence of the blood brain barrier (BBB), the conventional chemotherapeutic drugs are difficult to achieve effective treatment concentration through BBB. Our previous work showed that Muscone modified liposome can increase uptake of the cerebral vascular endothelial cells on RI7217 modified liposome, and improve the liposome brain targeting. But the stability of the ligand RI7217 is poor, and the immunogenicity of antibody is high. This project keeps using aroma resuscitative herbal ingredients of Muscone promote drug through BBB characteristics, and the use of nucleic acid aptamer GBI-10 with high affinity, low immunogenicity, good stability and specificity targeting recognition features of glioma cells, We will focus on developing muscone and aptamer cascade modified brain targeting delivery system loaded docetaxel again to glioma, in order to increase the chemotherapy drug cross BBB, improve the brain targeting, enhance the chemotherapeutic effect on glioma in the brain ,and reduce systemic toxicity. The research work is expected to combine with aromatic Chinese herbal medicine and modern targeting technology，and to promote BBB transparent mechanism and primary brain targeting mechanism in the whole animal, cell and molecular level, which will provide theoretical basis for further study of glioma chemotherapy.

脑胶质瘤的治疗仍是肿瘤领域最困难的挑战之一。由于血脑屏障（BBB）的存在，常规化疗药物难以透过BBB达到有效治疗浓度。我们前期工作发现麝香酮修饰的脂质体可增加脑血管内皮细胞对RI7217修饰靶向脂质体的摄取，提高该靶向脂质体进入脑内的量，但配体RI7217存在稳定性差、抗体免疫原性高等问题。本课题拟进一步利用芳香开窍类中药成分麝香酮促进药物透过BBB的特性，再利用亲和力高、免疫原性低、且稳定性好的核酸适配体GBI-10的特异性脑胶质瘤细胞靶向识别的特性，构建芳香开窍中药成分麝香酮和适配体级联修饰多烯紫杉醇脑靶向递药系统，以期增加化疗药物BBB透过率，提高脑靶向性，进而增强脑内抗胶质瘤的疗效、降低全身毒性。该研究工作将芳香中药的开窍作用和现代靶向技术相结合，在整体动物、细胞及分子水平上阐明该递送系统促进BBB通透机制及初步脑靶向机制，为进一步胶质瘤的化疗提供理论依据和研究基础。

脑胶质瘤的治疗仍是肿瘤领域最困难的挑战之一。由于脑胶质瘤呈浸润性增长，病程进展迅速，恶性脑胶质瘤患者的生存时间仅为 15-22 个月。目前多采用手术切除和放疗化疗进行术后辅助治疗的方法来治疗胶质瘤。由于血脑屏障的存在，阻碍了大部分药物进入脑内，常规化疗药物难以通过BBB在脑内达到有效治疗浓度。因此，为了增加血脑屏障通透性，促进药物透过血脑屏障到达脑胶质瘤部位，增加药物在脑胶质瘤内的药量。.本课题利用芳香开窍类中药成分麝香酮自身易透过 BBB及其促进药物透过 BBB 的特性，以麝香酮作为一级靶向配体，再利用核酸适配体 GBI-10 的特异性脑胶质瘤细胞靶向识别的特性，以 GBI-10 作为二级靶向配体，构建芳香开窍中药成分麝香酮和适配体级联修饰多烯紫杉醇脑靶向递药系统。我们研究发现该递送系统能增加化疗药物 BBB 透过率，提高脑靶向性，进而增强脑内抗.胶质瘤的疗效。在研究中我们还发现ApoE的修饰还可以进一步提高该递送系统对胶质瘤的靶向作用和治疗作用。.采用薄膜分散法制备ApoE、Mu和GBI-10共修饰的载多烯紫杉醇脂质体，粒径在105 nm - 120 nm之间，透射电镜下脂质体呈类球形，包封率在80% - 88%之间，稳定性良好。定性和定量摄取实验中，细胞对ApoE-Mu-GBI-10-DTX-LP摄取量最高，对Mu-GBI-10-DTX-LP摄取量高于Mu-DTX-LP和GBI-10-DTX-LP，在体外血脑屏障透过性实验中，ApoE-Mu-GBI-10-DTX-LP的Papp值最高，表现出良好的血脑屏障透过性。溶酶体逃逸结果显示ApoE-Mu-GBI-10-LP于12 h从U87-MG溶酶体中逃逸。与其他脂质体相比，小动物活体成像实验显示ApoE-Mu-GBI-10-DTX-LP在动物脑内荧光强度最强，对胶质瘤的靶向效果最好。划痕实验显示ApoE-Mu-GBI-10-DTX-LP对U87-MG细胞迁移能力的抑制作用最强；小鼠生长抑制实验结果显示ApoE-Mu-GBI-10-DTX-LP给药后，小鼠的生存率显著延长，表现出良好的治疗作用。表明ApoE、Mu和GBI-10级联修饰脂质体后能够显著增强DTX的抗胶质瘤作用。该研究对脑胶质瘤的术后化疗具有重要的意义。.