Abstract：
ABSTACTThe medicinal properties of genetic drugs are highly dependent on the design of delivery systems. Ionizable cationic lipids are considered core materials in delivery systems. However, there has not yet been a widespread consensus on the relationship between the wide diversity of lipid structure design and gene delivery efficiency. The aims of the research work were to synthesize ionizable cholesterol derivatives (iChol-lipids) and to evaluate their potential applications as gene delivery vector. A series of iChol-lipids with different head groups were synthesized with carbamate bond spacer. The chemical structures were characterized by 1H NMR, MS, melting range, and pKa. The interactions between iChol-lipids and MALAT1-siRNA were studied by molecular dynamics simulations and compared with market available DC-Chol, which revealed that hydrogen bonds, salt-bridge, and electrostatic interaction were probably involved. The self-assemble behaviors of these lipids were intensively investigated and evaluated by dynamic laser scattering in the presence of different helper lipids and PEGylated lipids. Their plasmid binding ability, transfection efficiency, hemolytic toxicity, and cytotoxicity were fully studied. IZ-Chol-LNPs was proved to be highly potential to effectively complex with DNA, and endosome escape mechanisms mediated by proton sponge effect was verified by pH-sensitive fluorescence probe BCFL.
摘要：
遗传药物的药用特性高度依赖于递送系统的设计。可电离的阳离子脂质被认为是递送系统中的核心材料。然而,关于脂质结构设计的广泛多样性与基因传递效率之间的关系，尚未达成广泛共识。研究工作的目的是合成可电离的胆固醇衍生物（iChol-lipides）并评估其作为基因递送载体的潜在应用。用氨基甲酸酯键间隔基合成了一系列具有不同头基的iChol-脂质。化学结构经1HNMR表征,MS,熔化范围,和pKa。通过分子动力学模拟研究了iChol-脂质与MALAT1-siRNA之间的相互作用，并与市场上可获得的DC-Chol进行了比较。这揭示了氢键，盐桥,可能涉及静电相互作用。在存在不同辅助脂质和聚乙二醇化脂质的情况下，通过动态激光散射对这些脂质的自组装行为进行了深入研究和评估。它们的质粒结合能力，转染效率，溶血毒性,和细胞毒性进行了充分的研究。IZ-Chol-LNP被证明具有与DNA有效复合的高度潜力，通过pH敏感的荧光探针BCFL验证了质子海绵效应介导的内体逃逸机制。
