乳糖-聚赖氨酸复合物对肝细胞导向能力的研究

目的 :利用肝细胞膜存在的去唾液酸糖蛋白受体 ,合成一种能够携带目的DNA分子特异性富集到肝组织中的载体。方法 :在弱碱性溶液中 ,在氰基硼氢化钠作用下 ,通过还原氨化法进行乳糖 (Lac)与聚赖氨酸 (PLL)的共价连接 ,SephadexG 10分离纯化产物 ;采用真核细胞表达基因 β 半乳糖苷酶报道基因 ,在细胞培养中和小鼠体内观察乳糖 聚赖氨酸复合物 (Lac PLL)对肝细胞的导向能力。结果 :Lac在氰基硼氢化钠作用下能有效地结合到PLL分子上 ,Lac与PLL的摩尔比为 16∶1;Lac PLL复合物在体外能够与DNA分子形成稳定偶联物 ,使其所偶联的DNA分子有效地进入到肝癌细胞 ,并使相应基因在细胞中表达。小鼠尾静脉注射DNA/Lac PLL偶联物10 μg后 ,DNA能有效地在肝组织中富集并在肝细胞中表达。结论 :Lac PLL是一种有效的对目的DNA分子具有肝细胞特异性导向能力的载体。

Target Delivery Ability of Lactose-Poly-L-Lysine to Parenchymal Liver Cells in vitro / in vivo

Purpose:To prepare a delivery carrier targeted the designed DNA molecule into the parenchymal liver cells based on the presence of asialo glycoprotein receptor on the liver cells.Methods:The lactose and poly L lysine covalently linked compound(Lac PLL)was prepared by reductive amination method in the presence of sodium cyanoborohydride in an alkalescent aqueous solution.The compound was purified by using Sephadex G 10 gel filtration.Eukaryotic expression reporter gene β galactosidase was used to analyse the target delivery ability of the Lac PLL in cell culture and in mice.Results:Lactose was efficiently bound to poly L lysine forms Lac PLL.In the compound the molar ratio of lactose and poly L lysine forms Lac PLL.In the compound the molar ratio of lactose and poly L lysine was 16∶1 .In vitro the Lac PLL could couple and carry the reporter gene into the hepatocellular carcinoma cells.In addition,the coupling reporter gene could express efficiently.After 10 μg of DNA/Lac PLL was injected into Balb/c mice by tail intravenous injection,the coupled reporter gene accumulated in the liver and expressed efficiently in the parenchymal liver cell.Conclusion: Lac PLL is an efficient carrier for DNA target to parenchymal liver cells.