自发曲线对脂单层的界面吸附和崩的影响
Bret A Brandner1, Shankar B Rananavare2, Stephen B Hall1
1Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon, United States.
概括
肺表面活性剂的快速吸附与其倾向于负曲率有关,但这也加速了崩. 平面结构,尽管负曲率,并不能防止崩,突出显示曲率动态的重要性.
科学领域:
- 生物物理学的生物物理.
- 材料科学 材料科学 材料科学
- 表面化学 表面化学
背景情况:
- 肺表面活性剂需要快速吸附到气膜空气/水接口,并在压缩下缓慢崩以获得有效的功能.
- 反向六角 (HII) 阶段的圆柱形单层,以负曲率为特征,表现出快速吸附.
- 形成HII结构可以破坏脂链包装,而状结构可以优化它.
研究的目的:
- 为了调查由具有负自发曲率的脂形成的平面层二层是否表现出快速吸附和缓慢崩.
- 确定自发曲线的作用和HII阶段在表面活性剂吸附和崩动态中的存在.
主要方法:
- 使用的二元混合物是二氧化酸胆-二氧化酸乙醇胺 (DOPC-DOPE) 与DOPE (XPE) 的不同分子分数的二元混合物.
- 采用小角度X射线散射 (SAXS) 来分析脂混合物的结构阶段 (状与HII).
- 测量了准备好的脂样本的吸附率和崩行为.
主要成果:
- 增加DOPE的分子分数 (更高的XPE) 导致了更负的自发曲线.
- 具有较高XPE的样本表明吸附加速,但也更快的崩.
- 微角X射线散射证实了只有叶片结构的存在,在研究范围内没有可检测到的HII相.
结论:
- 脂的天生的倾向形成负曲率对于快速吸附至关重要,比HII阶段的存在更重要.
- 平面状结构不足以缓解由自发曲线驱动的崩倾向.
- 吸附和崩可能涉及限制速度的短暂结构,具有显著的负曲率.
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