Department of Physical Chemistry and Electrochemistry, Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Krakow, Poland.
Environ Sci Process Impacts. 2019 Mar 20;21(3):438-445. doi: 10.1039/c8em00497h.
Lung surfactant (LS) occurs at the air-water interface in the alveoli. Its main function is to reduce the work needed to expand the alveoli during inhalation and prevent the alveolar collapse during exhalation. Disturbance of this complex interfacial system by the uptake of pollutant molecules can lead to changes in fluidity, permeability, phase separation and domain formation, which in turn can lead to serious impairment in lung function. Knowledge of the LS-pollutant interaction is essential for understanding the mechanism of this process. In this study, we investigate the interaction of LS models with benzo[a]pyrene (BaP). Dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylglycerol (DPPG) sodium salt, and their 4 : 1 mixture are used as LS models. Surface pressure-area isotherms and molecular dynamics simulations are employed to study the properties of LS monolayers. It was found that the addition of BaP has a destabilizing effect on the mixed DPPC/DPPG monolayer, manifested by the decrease in surface pressure. Compression of a monolayer during a respiratory cycle may expel BaP to the bulk solution. It was demonstrated that DPPG is an active component that prevents the BaP molecule from entering the water subphase; as a minor component of LS it can effectively reduce this process. In addition, the presence of BaP in LS models induces the reduction of monolayer hydration in the hydrophilic region and the increase in chain ordering in the hydrophobic region. The observed changes in monolayer fluidity and phase behavior can be a source of various lung function disorders.
肺表面活性剂 (LS) 存在于肺泡的气-液界面。其主要功能是降低吸气时扩张肺泡所需的功，并防止呼气时肺泡塌陷。污染物分子的摄取对这个复杂的界面系统的干扰，可能导致流动性、渗透性、相分离和域形成的变化，进而导致严重的肺功能障碍。了解 LS-污染物的相互作用对于理解这个过程的机制是至关重要的。在这项研究中，我们研究了 LS 模型与苯并[a]芘 (BaP) 的相互作用。二棕榈酰磷脂酰胆碱 (DPPC)、二棕榈酰磷脂酰甘油 (DPPG) 钠盐及其 4:1 的混合物被用作 LS 模型。表面压力-面积等温线和分子动力学模拟被用来研究 LS 单层的性质。结果表明，BaP 的加入对 DPPC/DPPG 混合单层有去稳定化作用，表现为表面压力的降低。呼吸循环中单层的压缩可能会将 BaP 挤出到体相溶液中。结果表明，DPPG 是一种活性成分，可阻止 BaP 分子进入水亚相；作为 LS 的次要成分，它可以有效地减少这个过程。此外，BaP 在 LS 模型中的存在诱导亲水区域单层水合作用的减少和疏水区域链序的增加。所观察到的单层流动性和相行为的变化可能是各种肺功能障碍的来源。
