Lipid chain geometry of C14 glycerol-based lipids: effect on lipoplex structure and transfection
Lipid chain geometry of C14 glycerol-based lipids: effect on lipoplex structure and transfection
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DOI：
10.1039/c0mb00149j
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发表时间：
2011-01-01
影响因子：
--
通讯作者：
Lawrence, M. Jayne
中科院分区：
文献类型：
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作者：
Kudsiova, Laila;Ho, Jimmy;Lawrence, M. Jayne
已经确定了 DOTMA C14 类似物的烷基链几何结构的系统改变对在不存在和存在 50 mol% DOPE 的情况下形成的所得阳离子囊泡的详细分子结构的影响，以及使用小牛胸腺或质粒 DNA 从这些囊泡制备的脂质复合物的影响。研究的 C14 DOTMA 类似物涉及 Delta 9 或 Delta 11 位处的顺式或反式双键，以及 C9 位处具有炔烃的化合物 (ALK)。对于所有这些类似物，通过光散射和中子散射、zeta 电位测量和负染色电子显微镜检查表明，无论掺入的 DNA 的性质如何，囊泡或所得脂质复合物的结构或电荷没有显着差异。然而，当通过凝胶电泳检查络合和释放的程度时，观察到由各种脂质形成的复合物之间存在差异，其中E-脂质似乎比所有其他测试的脂质更有效地络合DNA。此外，由E-脂质制备的脂质复合物对于MDA-MB-231乳腺癌细胞的转染是最有效的。通过共聚焦显微镜研究表明，E-脂质还表现出更高的内化能力和更分散的细胞分布，可能表明内体逃逸和/或核输入程度更大。这些观察结果表明，复合程度是决定所测试复合物转染效率的最重要因素。目前还不清楚为什么 E-脂质在复合 DNA 方面更有效，尽管人们认为每个分子的有效面积被阳离子脂质和 DOPE 头基占据，因此双层表面上的正电荷密度与 DNA 分子的负电荷密度最接近。考虑到阳离子脂质的几何形状，预计E-脂质的头基在每个分子中占据的面积比ALK或Z-脂质更小。
The effects have been determined of a systematic alteration of the alkyl chain geometry of a C14 analogue of DOTMA on the detailed molecular architecture of the resulting cationic vesicles formed both in the absence and presence of 50 mol% DOPE, and of the lipoplexes prepared from these vesicles using either calf thymus or plasmid DNA. The C14 DOTMA analogues studied involved cis- or trans-double bonds at positions Delta 9 or Delta 11, and a compound (ALK) featuring an alkyne at position C9. For all of these analogues, examination by light scattering and neutron scattering, zeta potential measurement, and negative staining electron microscopy showed that there were no significant differences in the structures or charges of the vesicles or of the resulting lipoplexes, regardless of the nature of the DNA incorporated. Differences were observed, however, between the complexes formed by the various lipids when examining the extent of complexation and release by gel electrophoresis, where the E-lipids appeared to complex the DNA more efficiently than all other lipids tested. Moreover, the lipoplexes prepared from the E-lipids were the most effective in transfection of MDA-MB-231 breast cancer cells. As indicated through confocal microscopy studies, the E-lipids also showed a higher internalisation capacity and a more diffuse cellular distribution, possibly indicating a greater degree of endosomal escape and/or nuclear import. These observations suggest that the extent of complexation is the most important factor in determining the transfection efficiency of the complexes tested. At present it is unclear why the E-lipids were more effective at complexing DNA, although it is thought that the effective area per molecule occupied by the cationic lipid and DOPE head groups, and therefore the density of positive charges on the surface of the bilayer most closely matches the negative charge density of the DNA molecule. From a consideration of the geometry of the cationic lipids it is anticipated that the head groups of the E-lipids would occupy a smaller area per molecule than the ALK or Z-lipids.