穿膜肽TAT和脑肿瘤靶向肽T7双修饰脂质体的制备和体外靶向性评价  

Cell penetrating peptide TAT and brain tumor targeting peptide T7 dual modified liposome preparation and in vitro targeting evaluation

作　　者：袁端锋 宗太丽[1] 高会乐[1] 何勤[1] 

机构地区：[1]四川大学华西药学院,靶向药物与传递系统教育部重点实验室,四川成都610041 [2]四川天联药业有限公司,四川成都610000

出　　处：《药学学报》2015年第1期104-110,共7页Acta Pharmaceutica Sinica

基　　金：国家自然科学基金面上项目(81373337);国家重大科学研究计划资助项目(2013CB932504)

摘　　要：本文旨在制备T7肽和穿膜肽TAT双修饰的脂质体（T7 and TAT dual modified liposomes,T7-TAT-LIP）用于血脑屏障和脑肿瘤细胞双级靶向药物递送。研究以CFPE为荧光探针,T7修饰的PEG-DSPE、TAT修饰的PEG-DSPE、卵磷脂、PEG-DSPE和胆固醇为材料,采用成膜水化法制备脂质体,对T7浓度、TAT浓度、连接T7和TAT的PEG长度进行优化,表征其粒径、zeta电位、形态和稳定性。以b End.3细胞和C6细胞为模型,考察T7-TAT-LIP的细胞摄取能力,表征其穿过血脑屏障和脑肿瘤细胞靶向能力。结果表明,T7用量为脂质的6%、修饰T7所用PEG链长为2000、TAT用量为脂质的0.5%、修饰TAT所用PEG链长为1000时所得到的双修饰脂质体被C6细胞摄取能力最强。优化后T7-TAT-LIP粒径为118 nm,zeta电位为-6.32 m V,透射电镜下形态圆整。脂质体在PBS中较为稳定,37℃放置24 h,浊度和粒径无明显变化;4~8℃放置1个月,粒径和PDI无明显变化。在不同时间点,b End.3和C6细胞摄取T7-TAT-LIP的强度均高于单配体修饰脂质体,且随着孵育时间提高,摄取浓度逐渐提高。这些结果说明,双修饰脂质体具有血脑屏障和脑肿瘤细胞双级靶向能力,且效果优于单配体修饰脂质体。The purpose of this study is to prepare T7 and TAT dual modified liposomes （T7-TAT-LIP） to penetrate through blood brain barrier and target to brain tumor cells. The liposomes were prepared with CFPE, T7 modified PEG-DSPE, TAT modified PEG-DSPE, soybean phospholipid, PEG-DSPE and cholesterol. The CFPE was used to track the cellular uptake efficiency. The density of T7 and TAT and the length of PEG were optimized, and then the liposomes were characterized by particle size, zeta potential, morphology and stability. Afterwards, the cellular uptake by bEnd.3 and C6 cells were evaluated. The results showed that the optimized parameters were 6% ofT7, 0.5% of TAT, the molecular weight of PEG for T7 was 2000 and the molecular weight of PEG for TAT was 1000. After optimization, the particle size of T7-TAT-LIP was 118 nm, the zeta potential was -6.32 mV and the particles were spherical. The turbidity and particle size of liposomes were not obviously changed after 24 h incubation in PBS at 37 ℃. The particle size and polydispersity index were also stable during 1 month incubation at 4-8 ℃. The cellular uptake by both bEnd.3 and C6 cells of T7-TAT-LIP was higher than that of T7 or TAT modified liposomes, suggesting dual modified liposomes possessed better blood brain barrier targeting ability and brain tumor targeting ability than the single ligand modified liposomes.

关 键 词：脂质体 穿膜肽 血脑屏障 脑肿瘤 

分 类 号：R943[医药卫生—药剂学]