School of Pharmacy, China Pharmaceutical University, Nanjing-210009, PR China.
J Control Release. 2010 Sep 15;146(3):299-308. doi: 10.1016/j.jconrel.2010.05.022. Epub 2010 May 23.
Ursodeoxycholic acid (UA) modified protein-lipid nanocomplex (uP-LNC) as a novel biomimetic nanocarrier was developed for tumor-targeting delivery. Bovine serum albumin (BSA) was used as a model protein and its amino groups were covalently modified by UA. Lipid nanoparticle (LNP) composed of phospholipids, triglycerides and octadecylamine was prepared by using solvent evaporation method and was used as the core. UA modified BSA (uP) was attached onto the surface of LNP by post-insert method and generated the protein-lipid nanocomplex. As the control, cholesteryl hemiglutarate (CH), a non-targeting ligand was also used to modify BSA and then formed CH modified protein-lipid nanocomplex (cP-LNC). The combining efficiency of modified BSA with LNP, determined by Bradford protein assay, increased with the enhancement of substitution degree. The modified BSA and nanocomplex were characterized for the substitute degree, average molecular weight, surface tension, particle size and zeta potential by various physicochemical analyses. In vitro dissolution tests and cell uptake studies were performed by loading coumarin-6 as a fluorescent probe. The results indicated that the UA modified protein attached on the nanoparticles significantly decreased drug release from the nanocomplex in pH 7.4 medium, The uptake of uP-LNC was higher in hepatic carcinoma cells (HepG2 and Bel 7402) than in normal liver cells (L02). Furthermore, the uptake of uP-LNC was significantly higher than that of cP-LNC and LNP in these cells. The uptake was dependent on time, temperature and concentration, and could be inhibited by free UA. In addition, the MTT assay of uP-LNC and u(x)P with various degrees of substitution showed very low cytotoxicity at tested concentrations in all cells. The UA modification served to facilitate the specific receptor and energy mediated endocytosis process of the protein-lipid nanocomplex and enabled this nanocomplex to be a potential nanocarrier for tumor-targeting drug delivery.
熊去氧胆酸（UA）修饰的蛋白-脂质纳米复合物（uP-LNC）作为一种新型仿生纳米载体，用于肿瘤靶向递药。牛血清白蛋白（BSA）被用作模型蛋白，其氨基通过 UA 共价修饰。脂质纳米粒（LNP）由磷脂、三酰甘油和十八烷基胺组成，采用溶剂蒸发法制备，并作为核心。通过后插入法将 UA 修饰的 BSA（uP）连接到 LNP 表面，形成蛋白-脂质纳米复合物。作为对照，也使用非靶向配体胆甾醇半琥珀酸酯（CH）来修饰 BSA，然后形成 CH 修饰的蛋白-脂质纳米复合物（cP-LNC）。通过 Bradford 蛋白分析测定，结合效率随着取代度的增加而增加。通过各种物理化学分析对修饰的 BSA 与 LNP 的结合效率、取代度、平均分子量、表面张力、粒径和 zeta 电位进行了表征。通过加载香豆素-6 作为荧光探针进行体外溶出试验和细胞摄取研究。结果表明，UA 修饰的蛋白附着在纳米颗粒上，显著降低了纳米复合物在 pH7.4 介质中的药物释放。uP-LNC 在肝癌细胞（HepG2 和 Bel 7402）中的摄取量高于正常肝细胞（L02）。此外，在这些细胞中，uP-LNC 的摄取量明显高于 cP-LNC 和 LNP。摄取量依赖于时间、温度和浓度，并且可以被游离 UA 抑制。此外，在所有细胞中，具有不同取代度的 uP-LNC 和 u(x)P 的 MTT 测定在测试浓度下显示出非常低的细胞毒性。UA 修饰有助于促进蛋白-脂质纳米复合物的特异性受体和能量介导的内吞过程，使该纳米复合物成为一种有潜力的肿瘤靶向药物递送的纳米载体。
