Callow P, Fragneto G, Cubitt R, Barlow D J, Lawrence M J
Institut Laue-Langevin, 6 rue Jules Horowitz, BP 156, 38042 Grenoble Cedex 9, France.
Langmuir. 2009 Apr 7;25(7):4181-9. doi: 10.1021/la802847h.
Transfection of cells by DNA for the purposes of gene therapy can be effectively engineered through the use of cationic lipid/DNA "lipoplexes", although the transfection efficiency of these complexes is sensitive to the neutral "helper" lipid included. Here, neutron reflectivity has been used to investigate the role of the helper lipid present during the interaction of these lipoplexes with model membranes composed primarily of zwitterionic lipid 1,2-dimyristoylphosphatidylcholine (DMPC) together with 10 mol % 1,2-dipalmitoylphosphatidylserine (DPPS). Dimethyldioctadecylammonium bromide (DDAB) vesicles were formed with two different helper lipids, 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine (DOPE) and cholesterol, and complexed with a 1:1 charge ratio of DNA. The interaction of these complexes with the supported phospholipid bilayer was determined. DOPE-containing lipoplexes were found to interact faster with the model cell membrane than those containing cholesterol, and complexes containing either of the neutral helper lipids were found to interact faster than when DDAB alone was present. The interaction between the lipoplexes and the model membrane was characterized by an exchange of lipid between the membrane and the lipid/DNA aggregates in solution; the deposition of(additional) lipid on the surface of the model cell membrane was not apparent.
尽管阳离子脂质/DNA“脂质复合物”中所含中性“辅助”脂质对其转染效率有影响，但通过使用阳离子脂质/DNA“脂质复合物”，可有效地实现用于基因治疗目的的细胞DNA转染。在此，利用中子反射率研究了这些脂质复合物与主要由两性离子脂质1,2-二肉豆蔻酰磷脂酰胆碱（DMPC）以及10摩尔%1,2-二棕榈酰磷脂酰丝氨酸（DPPS）组成的模型膜相互作用时辅助脂质的作用。用两种不同的辅助脂质1,2-二油酰-sn-甘油-3-磷酸乙醇胺（DOPE）和胆固醇形成二甲基二十八烷基溴化铵（DDAB）囊泡，并与电荷比为1:1的DNA复合。测定了这些复合物与支持的磷脂双层的相互作用。发现含DOPE的脂质复合物与模型细胞膜的相互作用比含胆固醇的脂质复合物更快，并且发现含有任何一种中性辅助脂质的复合物比仅存在DDAB时的相互作用更快。脂质复合物与模型膜之间的相互作用的特征是膜与溶液中的脂质/DNA聚集体之间发生脂质交换；在模型细胞膜表面没有明显的（额外）脂质沉积。
