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肿瘤新生血管内皮细胞特异性高表达一些能被某些配体识别的蛋白质。本文以阿霉素脂质体为载体,在体外细胞水平上比较研究了多肽RGD和NGR对于人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVEC)的靶向效果。本研究制备了阿霉素立体稳定脂质体(doxorubicin-loaded sterically stabilized liposomes,SSL-DOX),RGD(arginine-glycine-aspartic acid)或NGR(asparagine-glycine-arginine)修饰的立体稳定脂质体(RGD-SSL-DOX或NGR-SSL-DOX),并对其粒径、Zeta电位、包封率和释放等性质进行了研究。通过针对HUVEC细胞的流式细胞术、激光共聚集显微技术以及SRB测定在体外水平上研究两个多肽对于肿瘤血管内皮细胞的靶向效果。本研究中制备的脂质体包封率达到98%以上,粒径约65-75nm,表面带弱的负电荷。体外释放实验证明RGD或NGR的修饰没有改变脂质体的释放行为。流式细胞实验中,SSL-DOX,NGR-SSL-DOX,RGD-SSL-DOX和阿霉素溶液中阿霉素被HUVEC摄取的顺序为:阿霉素溶液>RGD-SSL-DOX>NGR-SSL-DOX>SSL-DOX,配体修饰脂质体中的阿霉素进入细胞后分布在细胞核和细胞质内,而SSL-DOX内的药物仅分布在细胞核中。SRB实验中各制剂的细胞毒顺序与摄取实验中的顺序相同。脂质体的性质表征研究说明脂质体表面的配体修饰没有影响立体稳定脂质体的各项性质。由于配体介导的内吞作用,相对未经修饰的脂质体,配体修饰脂质体处理的HUVEC摄取的阿霉素有所增多,并且RGD-SSL-DOX的靶向效果强于NGR-SSL-DOX。
Tumor neovascular endothelial cells express high levels of specific proteins that are recognized by certain ligands. In this paper, doxorubicin liposomes as a carrier in vitro compared the level of peptides RGD and NGR on human umbilical vein endothelial cells (human umbilical vein endothelial cells, HUVEC) targeting effect. In this study, three-dimensional stable liposomes of doxorubicin-loaded sterically stabilized liposomes (SSL-DOX), RGD (arginine-glycine-aspartic acid) or asparagine-glycine-arginine (RGD-SSL-DOX or NGR-SSL-DOX). The particle size, Zeta potential, entrapment efficiency and release properties were studied. The targeted effect of two polypeptides on tumor vascular endothelial cells was investigated at the in vitro level by flow cytometry against HUVEC cells, laser co-aggregation microscopy and SRB assay. The encapsulation efficiency of the liposome prepared in this study reached more than 98% with a particle size of about 65-75 nm and a weak negative charge on the surface. In vitro release experiments demonstrated that the modification of RGD or NGR did not alter the release behavior of the liposomes. In flow cytometry, the uptake of doxorubicin by HUVEC in SSL-DOX, NGR-SSL-DOX, RGD-SSL-DOX and doxorubicin solutions was as follows: doxorubicin solution> RGD-SSL-DOX> SSL-DOX> SSL-DOX, ligand-modified doxorubicin in liposomes enter the cell and distribute in the nucleus and cytoplasm, while the drug in SSL-DOX is only distributed in the nucleus. The cytotoxic sequence of each formulation in the SRB experiment was the same as in the uptake experiment. Characterization of Liposomes Characterization studies indicate that ligand modifications on the surface of liposomes do not affect the properties of sterically stabilized liposomes. Due to ligand-mediated endocytosis, there was an increase in uptake of doxorubicin by ligand-modified liposome-treated HUVECs relative to unmodified liposomes and RGD-SSL-DOX was more targeted than NGR -SSL-DOX.