Max Planck Institute of Colloids and Interfaces, Science Park Potsdam-Golm, Am Mühlenberg 1, 14476 Potsdam, Germany.
Phys Chem Chem Phys. 2018 Mar 7;20(10):6936-6944. doi: 10.1039/c8cp00047f.
The influence of the chain composition on the physical-chemical properties will be discussed for five transfection lipids containing the same lysine-based head group. For this purpose, the chain composition will be gradually varied from saturated tetradecyl (C) and hexadecyl (C) chains to longer but unsaturated oleyl (C) chains with double bonds in the cis configuration. In this work, we investigated the lipids as Langmuir monolayers at the air-water-interface in the absence and presence of calf thymus DNA applying different techniques such as infrared reflection absorption spectroscopy (IRRAS) and grazing incidence X-ray diffraction (GIXD). The replacement of saturated tetradecyl (C) and hexadecyl (C) chains by unsaturated oleyl (C) chains increases the fluidity of the lipid monolayer: TH10 < TT10 < OH10 < OT10 < OO10 resulting in a smaller packing density. TH10 forms the stiffest and OO10 the most fluid monolayer in this structure-property study. OO10 has a higher protonation degree compared to the saturated lipids TT10 and TH10 as well as to the hybrids OT10 and OH10 because of a better accessibility of the amine groups. Depending on the bulk pH, different scenarios of DNA coupling to the lipid monolayers have been proposed.
将讨论五种含有相同赖氨酸头部基团的转染脂质的链组成对物理化学性质的影响。为此，将逐步改变链组成，从饱和的十四烷基（C）和十六烷基（C）链变为更长但不饱和的顺式构型双键油酸基（C）链。在这项工作中，我们研究了在缺乏和存在小牛胸腺 DNA 的情况下，作为气液界面 Langmuir 单层的脂质，应用了不同的技术，如红外反射吸收光谱（IRRAS）和掠入射 X 射线衍射（GIXD）。用不饱和油酸基（C）链取代饱和十四烷基（C）和十六烷基（C）链会增加脂质单层的流动性：TH10 < TT10 < OH10 < OT10 < OO10，导致包装密度减小。在这项结构-性质研究中，TH10 形成最硬的单层，OO10 形成最流动的单层。与饱和脂质 TT10 和 TH10 以及杂种 OT10 和 OH10 相比，OO10 由于胺基的更好可及性，具有更高的质子化程度。根据体相 pH 值，提出了 DNA 与脂质单层偶联的不同方案。
