pH和靶头密度对FcBP修饰的PEG-PCL胶束在Caco-2细胞上摄取与外排的影响  

The effect of pH and ligand density on the endocytosis and exocytosis process of FcBP decorated PEG-PCL micelles on Caco-2 cells

作　　者：宋晓宁[1] 李瑞[1] 张华[1] 代文兵[1] 何冰[1] 郑颖[2] 张强[1] 王学清[1] 

机构地区：[1]北京大学药学院,北京100191 [2]澳门大学中华医药研究院,中药质量研究国家重点实验室,中国澳门999078

出　　处：《药学学报》2017年第8期1331-1336,共6页Acta Pharmaceutica Sinica

基　　金：国家自然科学基金资助项目(81473159);国家自然科学基金-海外及港澳学者合作研究基金资助项目(81528021)

摘　　要：利用小肠上皮细胞顶膜侧和基底侧pH的差异以及新生儿Fc受体(neonatal Fc receptor,FcRn)与其配体结合的pH依赖特性可能增加配体修饰的纳米载体从小肠上皮细胞顶膜侧向基底侧的转运,从而促进药物的吸收。本课题制备了靶向于FcRn的短肽FcBP(IgG Fc段结合肽,IgG Fc domain-binding peptides)修饰的聚乙二醇-聚ε-己内酯[poly(ethyl ethylene phosphate)-co-poly(ε-caprolactone),PEG-PCL]胶束并在人克隆结肠腺癌细胞(human colon adenanocaricinoma cell lines,Caco-2)上考察了pH和靶头密度对胶束摄取与外排过程的影响。采用薄膜水化法制备不同靶头修饰密度的包载香豆素6(coumarin 6,C6)的PEG-PCL主动胶束和被动胶束,并用激光粒度测定仪测定其粒径,透射电镜观察其形态,流式细胞术测定各主、被动胶束在不同pH值下的摄取和外排以及FcRn在胶束摄取中的作用。结果表明,PEG-PCL胶束的粒径约为30 nm,FcBP的修饰不影响胶束的粒径。pH和靶头密度都对FcBP修饰的PEG-PCL胶束的摄取有影响。主动胶束在pH 6.0的摄取量显著高于在pH7.4的摄取量,并且在两种pH下主动胶束的摄取量都表现出随靶头密度的增大先增大后减少的趋势。进一步研究胶束的外排表明,胶束在pH 6.0下摄取后可以在pH 7.4环境中外排,外排量与靶头密度有关,其中靶头密度10%的主动胶束外排量最大,显示出较强的跨膜转运递送的潜力。同时,竞争性抑制实验验证了胶束的摄取与配体和受体的作用有关。本研究为应用FcBP修饰的PEG-PCL胶束进行跨膜转运药物打下一定的基础,为纳米载体的设计提供了一定的参考。The difference in pH between apical and basolateral side of intestinal epithelial and pH dependence character of the combination of FcRn（neonatal Fc receptor） and ligand might improve the delivery of hydrophobic drugs by facilitating the transcytosis of nanocarriers. Here we designed FcBP（IgG Fc domain-binding peptides） decorated coumarin 6（C6） loaded poly（ethyl ethylene phosphate）-co-poly（ε-caprolactone）（PEG-PCL） micelles with different ligand densities to study the effect of p H and ligand density on the endocytosis and exocytosis process of micelles on human colon adenanocaricinoma cell lines（Caco-2）. Active micelles with different ligand densities and passive micelles were prepared using the thin-film hydration method. The size of the micelles was characterized by dynamic light scattering analysis and the morphology was observed by transmission electron microscope. The endocytosis and exocytosis of the micelles at pH 7.4 and pH 6.0, as well as the effect of Fc Rn on the endocytosis, were investigated by flow cytometry. The results showed that the size of micelles was about 30 nm, which was not affected by FcBP decoration. We found that pH and ligand density could both influence the endocytosis. The uptake of active micelles was higher at pH 6.0 than at pH 7.4, and an optimal ligand density of endocytosis was appeared in both pH environment. Then we proved that Fc BP decorated micelles could be endocytosed at pH 6.0 and exocytosed at pH 7.4, and the exocytosis process was also related to ligand density. Micelles with 10% ligand density had the largest exocytosis, showing the potentiality to deliver drugs through the intestinal epithelial. In addition, the competitive inhibition experiments illustrated that the interaction between FcRn and FcBP were essential to endocytosis. The results will enhance the understanding on the FcBP decorated PEG-PCL micelles for transmemberane drug delivery.

关 键 词：胶束 摄取与外排 新生儿Fc受体 IgG Fc段结合肽 PH 靶头密度 

分 类 号：I43[文学—其他各国文学]