Phase transitions of the pulmonary surfactant film at the perfluorocarbon-water interface
Phase transitions of the pulmonary surfactant film at the perfluorocarbon-water interface
复制标题
DOI：
10.1016/j.bpj.2023.04.010
复制
发表时间：
2023-05-16
影响因子：
3.4
通讯作者：
Zuo，Yi Y.
中科院分区：
文献类型：
--
作者：
Li，Guangle;Xu，Xiaojie;Zuo，Yi Y.
肺表面活性物质是一种脂质-蛋白质复合物，在肺的空气-水表面形成薄膜。这种表面活性剂膜限定了肺的弹性回缩和呼吸力学。在液体通气中使用含氧全氟化碳（PFC）作为呼吸介质的一个普遍接受的理由是利用其低表面张力（14-18 mN/m），这被认为使PFC成为外源性表面活性剂的理想替代品。相对于肺表面活性物质膜在空气-水表面的磷脂相行为的广泛研究，其在PFC-水界面的相行为基本上是未知的。在这里，我们报告了第一个详细的生物物理研究的磷脂相变在两个动物来源的天然肺表面活性物质膜，Infasurf和Survanta，在PFC-水界面，使用约束滴表面活性测定。约束液滴表面活性测定允许原位Langmuir-Blodgett转移从PFC-水界面，从而允许直接可视化的脂质多态性在肺表面活性物质膜使用原子力显微镜。我们的数据表明，无论其低表面张力，PFC不能被用作液体通气中肺表面活性剂的替代品，其中肺的空气-水表面被PFC-水界面所取代，该界面具有固有的高界面张力。肺表面活性剂膜在PFC-水界面经历连续的相变在表面压力小于平衡扩散压力50 mN/m和单层到多层的过渡高于此临界压力。这些结果不仅为天然肺表面活性物质在油-水界面的相行为提供了新的生物物理学见解，而且还对液体通气和液体呼吸技术的进一步发展产生了深远的影响。
Pulmonary surfactant is a lipid-protein complex that forms a thin film at the air-water surface of the lungs. This surfactant film defines the elastic recoil and respiratory mechanics of the lungs. One generally accepted rationale of using oxygenated perfluorocarbon (PFC) as a respiratory medium in liquid ventilation is to take advantage of its low surface tensions (14–18 mN/m), which was believed to make PFC an ideal replacement of the exogenous surfactant. Compared with the extensive studies of the phospholipid phase behavior of the pulmonary surfactant film at the air-water surface, its phase behavior at the PFC-water interface is essentially unknown. Here, we reported the first detailed biophysical study of phospholipid phase transitions in two animal-derived natural pulmonary surfactant films, Infasurf and Survanta, at the PFC-water interface using constrained drop surfactometry. Constrained drop surfactometry allows in situ Langmuir-Blodgett transfer from the PFC-water interface, thus permitting direct visualization of lipid polymorphism in pulmonary surfactant films using atomic force microscopy. Our data suggested that regardless of its low surface tension, the PFC cannot be used as a replacement of pulmonary surfactant in liquid ventilation where the air-water surface of the lungs is replaced with the PFC-water interface that features an intrinsically high interfacial tension. The pulmonary surfactant film at the PFC-water interface undergoes continuous phase transitions at surface pressures less than the equilibrium spreading pressure of 50 mN/m and a monolayer-to-multilayer transition above this critical pressure. These results provided not only novel biophysical insight into the phase behavior of natural pulmonary surfactant at the oil-water interface but also translational implications into the further development of liquid ventilation and liquid breathing techniques.