N-乙酰半乳糖胺修饰的肝靶向香豆素-6脂质体制备及评价

摘要

目的:本研究采用酶促法构建N-乙酰半乳糖胺(N-acetylgalactosamine,GalNAc)修饰的脂质体作为荧光标记物-香豆素-6的载体,对其修饰的脂质体理化性质进行评价.方法:采用酶催化法偶联合成GalNAc-C8-Chol,利用MS,NMR对其结构进行表征,并以此作为导向性材料,采用薄膜分散-挤出法制备载香豆素-6的GalNAc修饰肝靶向脂质体(NGAL-LP),并对脂质体的包封率、粒径、Zeta电位、体外释放度及RCA120体外结合效率等性质进行了考察.结果:合成的GalNAc-C8-Chol经MS,NMR鉴定为目标产物.与普通香豆素-6脂质体(LP)相比,本研究所制备的主动肝靶向脂质体(NGAL-LP)的粒径、Zeta电位、包封率、体外释放等理化性质无显著差异,包封率≥98％,平均粒径为(86.74±1.7) nm,平均Zeta电位为(-51.47±0.9) mV.体外释放结果表明,36 h内香豆素-6脂质体在PBS和血浆中的累积释放率＜8％.RCA120凝集实验表明,只有GalNAc-C8-Chol修饰的脂质体可经RCA120诱导产生凝集效应.结论:采用酶促法成功构建了GalNAc修饰的香豆素-6肝靶向脂质体,以期望显著提高体内肝肿瘤的靶向治疗效果.%Objective:To construct the N-acetylgalactosamine (GalNAc)-modified liposomes as the carriers of coumarin 6 by enzymatic method and evaluate its physicochemical property.Methods:The GalNAc-C8-Chol was synthesized by enzyme catalysis.The structure characterization of the product was confirmed by MS and NMR.The GalNAc-C8-Chol-modified coumarin 6-loaded liver targeting liposomes (NGAL-LP) were prepared by thin film dispersion-extrusion method.The encapsulation efficiency,particle size,Zeta potential and in vitro drug release of NGAL-LP were investigated.The in vitro lectin-induced aggregation of NGAL-LP was evaluated using Ricinus communis agglutinin (RCA120) assay.Results:The encapsulation efficiency of NGAL-LP was above 98％ and the modification of GalNAc-C8-Chol didn't affect its physicochemical characteristics,such as particle size,Zeta potential,encapsulation efficiency and in vitro drug release.The average size and Zeta potential of NGAL-LP were (86.74 ± 1.7)nm and (-51.47 ± 0.9) mV,respectively.There was no obvious difference in the in vitro release of coumarin 6 between the LP and NGAL-LP,which were both below 8％.RCA assay revealed enhanced aggregation of NGAL-LP compared to LP,confirming the presence of galactose on the surface of NGAL-LP.Conclusion:NGAL-LP was constructed successfully by enzymatic method and could be a potential formulation for targeted therapy of liver cancer.