An investigation of pulmonary surfactant physicochemical behavior under airway reopening conditions
An investigation of pulmonary surfactant physicochemical behavior under airway reopening conditions
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DOI：
10.1152/jappl.2000.88.2.493
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发表时间：
2000-02-01
影响因子：
3.3
通讯作者：
Gaver, DP
中科院分区：
文献类型：
--
作者：
Ghadiali, SN;Gaver, DP
气道重新开放机制取决于表面活性剂的理化性质。在重新打开过程中，一根手指的空气沿着气道行进会形成一个界面，该界面不断扩展到大量液体中。传统的表面活性剂无法评估这些条件下的物理化学行为。为了研究这些方面，我们研究了将半无限气泡推入半径为 R 的充满液体的圆柱形毛细管所需的压力。研究了离子表面活性剂 SDS 和肺表面活性剂类似物 L-α-二棕榈酰磷脂酰胆碱和 Infasurf。我们发现表面活性剂的非平衡吸附会产生很大的非平衡正应力和表面剪切应力（马兰戈尼应力），从而增加气泡压力。非生理性表面活性剂SDS能够消除正常应激并部分减轻Marangoni应激。肺表面活性剂的主要成分 L-α-二棕榈酰磷脂酰胆碱不能减轻任何压力，表现出缓慢的吸附特性。临床相关的表面活性剂 Infasurf 具有中等吸附特性，因此非平衡正应力降低，但 Marangoni 应力仍然很大。 Infasurf 的行为表明，最佳的表面活性剂溶液将具有足够快的吸附特性，以降低可能损害气道壁上皮细胞的重新开放压力，但足够慢以维持增强气道稳定性的马兰戈尼应力。
Airway reopening mechanics depend on surfactant physicochemical properties. During reopening, the progression of a finger of air down an airway creates an interface that is continually expanding into the bulk fluid. Conventional surfactometers are not capable of evaluating physicochemical behavior under these conditions. To study these aspects, we investigated the pressure required to push a semi-infinite bubble of air down a fluid-filled cylindrical capillary of radius R. The ionic surfactant SDS and pulmonary surfactant analogs L-alpha-dipalmitoylphosphatidylcholine and Infasurf were investigated. We found that the nonequilibrium adsorption of surfactant can create a large nonequilibrium normal stress and a surface shear stress (Marangoni stress) that increase the bubble pressure. The nonphysiological surfactant SDS is capable of eliminating the normal stress and partially reducing the Marangoni stress. The main component of pulmonary surfactant, L-alpha-dipalmitoylphosphatidylcholine, is not capable of reducing either stress, demonstrating slow adsorption properties. The clinically relevant surfactant Infasurf is shown to have intermediate adsorption properties, such that the nonequilibrium normal stress is reduced but the Marangoni stress remains large. Infasurf's behavior suggests that an optimal surfactant solution will have sorption properties that are fast enough to reduce the reopening pressure that may damage airway wall epithelial cells but slow enough to maintain the Marangoni stress that enhances airway stability.