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

Preparation and in vitro evaluation of GalNac-modified liposomes containing coumarin 6

目的:本研究采用酶促法构建N-乙酰半乳糖胺(N-acetylgalactosamine,Gal NAc)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Gal NAc-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Gal NAc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Gal NAc-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)m V。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Gal NAc-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Gal NAc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-Cs-Chol was synthesized by enzyme catalysis. The structure characterization of the product was confirmed by MS and NMR. The GalNAc-Cs-Chol-modified eoumarin 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-Cs-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.