Olzyńska Agnieszka, Jurkiewicz Piotr, Hof Martin
J. Heyrovský Institute of Physical Chemistry of the ASCR, v. v. i., Dolejskova 3, Prague 8, 18223, Czech Republic.
J Fluoresc. 2008 Sep;18(5):925-8. doi: 10.1007/s10895-008-0321-6. Epub 2008 Feb 7.
The need for detailed biophysical description of cationic lipid membranes, which are commonly used as gene transfection vectors, led us to study the properties of mixed cationic/zwitterionic lipid bilayers. Fluorescence solvent relaxation measurements of 6-dodecanoyl-2-dimethylaminonaphthalene (Laurdan) incorporated in a membrane consisting of cationic dimyristoyltrimethylammoniumpropane (DMTAP) and zwitterionic dimyristoylphosphatidylcholine (DMPC) were performed. The obtained results are compared with a recently measured system consisting of dioleoyltrimethylammoniumpropane (DOTAP) and dioleoylphosphatidylcholine (DOPC) (Jurkiewicz et al. Langmuir 22:8741-8749, 2006). The similar nonmonotonic dependence of the relaxation kinetics on cationic lipid content in the membrane was present for both systems. While the slowest solvent relaxation have been observed for 30 mol% of DOTAP in the DOPC bilayer (Jurkiewicz et al. Langmuir 22:8741-8749, 2006), for DMPC/DMTAP system it was found at 45 mol% of DMTAP, which agrees with the literature. Both membranes increased their hydration upon increased cationic lipid content.
由于常用作基因转染载体的阳离子脂质膜需要详细的生物物理描述，我们开展了对阳离子/两性离子混合脂质双层性质的研究。我们对掺入由阳离子二肉豆蔻酰基三甲基铵丙烷（DMTAP）和两性离子二肉豆蔻酰基磷脂酰胆碱（DMPC）组成的膜中的6-十二烷酰基-2-二甲基氨基萘（Laurdan）进行了荧光溶剂弛豫测量。将所得结果与最近测量的由二油酰基三甲基铵丙烷（DOTAP）和二油酰基磷脂酰胆碱（DOPC）组成的系统进行比较（Jurkiewicz等人，《朗缪尔》22:8741 - 8749，2006年）。两个系统中均存在弛豫动力学对膜中阳离子脂质含量类似的非单调依赖性。虽然在DOPC双层中30 mol%的DOTAP时观察到最慢的溶剂弛豫（Jurkiewicz等人，《朗缪尔》22:8741 - 8749，2006年），但对于DMPC/DMTAP系统，在45 mol%的DMTAP时发现最慢的溶剂弛豫，这与文献一致。随着阳离子脂质含量增加，两种膜的水合作用均增强。
