摘要
目的验证半乳糖化脂质体去唾液酸糖蛋白受体(ASGPr)介导体外HepG2细胞靶向性,考察脂质体粒径及PEG修饰对靶向性的影响。方法以新型半乳糖化胆固醇(5-胆甾烯-3β-氧基)4-氧代-4-[2-乳糖酰胺基乙氨基]丁酸酯(CHS-ED-LA)为靶向辅料制备半乳糖化脂质体(GalL)。将荧光磷脂标记的各脂质体加入到培养的HepG2或HeLa细胞中,在实验条件下共同培养后,用荧光分光光度计测定脂质体与细胞的结合量。结果 CHS-ED-LA修饰可将脂质体与HepG2细胞(表达ASGPr)的结合量提高2倍,但对HeLa细胞(不表达ASGPr)的结合量无影响;去唾液酸胎球蛋白(AF)饱和ASGPr结合位点后,GalL与HepG2细胞的结合量显著降低,与CL相近。平均粒径80nm的GalL与HepG2细胞结合量是CL的2.2倍;平均粒径为200nm时,GalL和CL的细胞结合量均降低,且无显著差异。PEG修饰后,脂质体与HepG2细胞的结合量均有所下降,但PEG包衣半乳糖化脂质体(PEG-GalL)的结合量为PEG包衣普通脂质体(PEG-CL)的1.7倍。结论 GalL可特异性靶向表达ASGPr的细胞,且粒径增加或PEG修饰均可降低脂质体的靶向性。
Objective To verify that the targeting of galactosylated liposomes(GalL) to HepG2 cells in vitro was via ASGPr-mediated endocytosis,and investigate the effect of particle size and PEG modification on the targeting ability.Methods A novel galactosylated lipid,(5-Cholesten-3β-yl) 4-oxo-4-[2-(lactobionyl amido) ethylamido] butanoate(CHS-ED-LA),was used as the "homing molecule" to form GalL.Liposomes labeled with NBD-PE were incubated with HepG2 cells,and the uptake of liposomes by HepG2 cells was examined by measuring the binding capacity of liposomes using fluorescence spectrophotometer.Results The incorporation of CHS-ED-LA could double the binding capacity of liposomes with HepG2 cells expressing ASGPr,but had no effect on the binding with HeLa cells lack of ASGPr.After pretreating HepG2 cells with asialofetuin(AF),the binding capacity of GalL with HepG2 cells decreased,and there was no difference on the binding capacity between GalL and CL cells.The binding capacity of GalL with a mean particle size of 80 nm to HepG2 cells was 2.2 times of that of CL;while for the GalL of about 200 nm,the binding capacity of GalL decreased and had no difference with that of CL.Although the PEG modification to GalL or CL decreased their binding capacity with HepG2 cells,the binding capacity of pegylated galactosylated liposomes(PEG-GalL) was still 1.7 times of that of pegylated liposomes(PEG-CL).Conclusion The results strongly suggested that HepG2 specifically took up GalL through ASGPr-mediated endocytosis.It could also be concluded that the targeting ability of GalL decreased due to the increase of particle size and PEG modification of the liposomes.
出处
《中国药剂学杂志（网络版）》
2011年第6期119-125,共7页
Chinese Journal of Pharmaceutics：Online Edition
