Enhanced surfactant adsorption via polymer depletion forces: a simple model for reversing surfactant inhibition in acute respiratory distress syndrome.
Enhanced surfactant adsorption via polymer depletion forces: a simple model for reversing surfactant inhibition in acute respiratory distress syndrome.
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DOI：
10.1529/biophysj.106.091157
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发表时间：
2007
影响因子：
3.4
通讯作者：
P. Stenger;J. Zasadzinski
中科院分区：
文献类型：
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作者：
P. Stenger;J. Zasadzinski
在急性呼吸窘迫综合征期间，肺表面活性物质对空气-水界面的吸附受到白蛋白和其他表面活性血清蛋白竞争吸附所造成的能量障碍的强烈抑制。表面活性物质吸附的减少导致肺表面张力的增加和呼吸功的增加。表面活性剂吸附的减少是用经典的Smolukowski胶体稳定性分析的一种变化来定量描述的。吸附在界面上的白蛋白对5k(B)T量级的表面活性剂扩散产生了一个能垒，导致吸附的减少，相当于将表面活性剂的浓度降低了100倍。在亚相中加入亲水性、不吸附的聚合物，如聚乙二醇，可在表面活性剂聚集体和消除能量障碍的界面之间提供耗竭吸引力。根据简单的Asakura和Oosawa耗竭吸引模型预测，表面活性物质的吸附随聚合物浓度呈指数增加。耗竭力很可能被用来克服在各种液-气和固-液界面上的吸附障碍。
Lung surfactant adsorption to an air-water interface is strongly inhibited by an energy barrier imposed by the competitive adsorption of albumin and other surface-active serum proteins that are present in the lung during acute respiratory distress syndrome. This reduction in surfactant adsorption results in an increased surface tension in the lung and an increase in the work of breathing. The reduction in surfactant adsorption is quantitatively described using a variation of the classical Smolukowski analysis of colloid stability. Albumin adsorbed to the interface induces an energy barrier to surfactant diffusion of order 5 k(B)T, leading to a reduction in adsorption equivalent to reducing the surfactant concentration by a factor of 100. Adding hydrophilic, nonadsorbing polymers such as polyethylene glycol to the subphase provides a depletion attraction between the surfactant aggregates and the interface that eliminates the energy barrier. Surfactant adsorption increases exponentially with polymer concentration as predicted by the simple Asakura and Oosawa model of depletion attraction. Depletion forces can likely be used to overcome barriers to adsorption at a variety of liquid-vapor and solid-liquid interfaces.