Nishikawa M, Takemura S, Takakura Y, Hashida M
Department of Drug Delivery Research, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
J Pharmacol Exp Ther. 1998 Oct;287(1):408-15.
In vivo receptor-mediated targeting of plasmid DNA to hepatocytes was achieved through optimizing the physicochemical and pharmacokinetic properties of a plasmid DNA/carrier complex. Galactosylated poly(L-lysine) (Gal-PLL) was synthesized using PLL with a molecular weight of 1,800, 13,000 or 29,000 without loss of the cationic charge. Plasmid DNA encoding chloramphenicol acetyltransferase was complexed with each Gal-PLL. A larger amount of PLL1800 is required for the complex formation than with PLL13000 and PLL29000, and increasing the number of galactose units on Gal-PLL resulted in reduced binding to plasmid DNA. The particle size and zeta-potential of the complexes varied depending on the mixing ratio and Gal-PLL used. Then, plasmid DNA/Gal-PLL complexes having diameters of 200 nm or less and a weak negative charge were prepared. After i.v. injection of [32P]plasmid DNA/Gal13-PLL13000 and [32P]plasmid DNA/Gal26-PLL29000, almost 80% of the radioactivity rapidly accumulated in the liver, preferentially in the parenchymal cells. The hepatic uptake clearances (CLliver) were much greater than any of the other tissue uptake clearances. Compared with these complexes, [32P]plasmid DNA/Gal5-PLL1800 and [32P]plasmid DNA/Gal5-PLL13000 had a smaller CLliver, suggesting that both the molecular weight of PLL and the degree of galactose modification determine the hepatic targeting of plasmid DNA. In vitro and in vivo gene expression studies revealed that plasmid DNA/Gal13-PLL13000 and plasmid DNA/Gal26-PLL29000 complexes are superior to plasmid DNA/Gal5-PLL1800 complex for introducing DNA into cells. These results demonstrated that an optimal design of a DNA/carrier complex based on physicochemical properties and a pharmacokinetic analysis of the distribution properties leads to successful in vivo gene delivery.
通过优化质粒 DNA/载体复合物的物理化学和药代动力学特性，实现了体内受体介导的质粒 DNA 对肝细胞的靶向作用。使用分子量为 1800、13000 或 29000 的聚-L-赖氨酸（PLL）合成了半乳糖基化聚-L-赖氨酸（Gal-PLL），且阳离子电荷未损失。将编码氯霉素乙酰转移酶的质粒 DNA 与每种 Gal-PLL 复合。与 PLL13000 和 PLL29000 相比，复合物形成需要更多量的 PLL1800，并且增加 Gal-PLL 上半乳糖单元的数量会导致与质粒 DNA 的结合减少。复合物的粒径和 ζ 电位根据混合比例和所使用的 Gal-PLL 而有所不同。然后，制备了直径小于 200 nm 且带弱负电荷的质粒 DNA/Gal-PLL 复合物。静脉注射[32P]质粒 DNA/Gal13-PLL13000 和[32P]质粒 DNA/Gal26-PLL29000 后，几乎 80%的放射性迅速在肝脏中积累，优先在实质细胞中。肝脏摄取清除率（CLliver）远高于任何其他组织摄取清除率。与这些复合物相比，[32P]质粒 DNA/Gal5-PLL1800 和[32P]质粒 DNA/Gal5-PLL13000 的 CLliver 较小，表明 PLL 的分子量和半乳糖修饰程度均决定了质粒 DNA 的肝脏靶向作用。体外和体内基因表达研究表明，质粒 DNA/Gal13-PLL13000 和质粒 DNA/Gal26-PLL29000 复合物在将 DNA 导入细胞方面优于质粒 DNA/Gal5-PLL1800 复合物。这些结果表明，基于物理化学特性和分布特性的药代动力学分析对 DNA/载体复合物进行优化设计可实现成功的体内基因递送。
