Structures of pulmonary surfactant films adsorbed to an air-liquid interface in vitro
Structures of pulmonary surfactant films adsorbed to an air-liquid interface in vitro
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DOI：
10.1016/j.bbamem.2005.11.007
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发表时间：
2005-12-30
影响因子：
3.4
通讯作者：
Schürch, S
中科院分区：
文献类型：
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作者：
Bachofen, H;Gerber, U;Schürch, S
当磷脂膜吸附到可固化的低相时，磷脂膜可以在体外保存。将天然表面活性剂、脂类提取物表面活性剂和人工表面活性剂的悬浮液加入海藻酸钠溶液中，并填充到自控气泡表面测定仪(CBS)中。通过吸附到CBS的气泡上形成表面活性剂薄膜进行功能测试。在气泡亚相中有无藻酸盐形成的膜在准静态或动态压缩时的吸附、膜的可压缩性或最小表面张力没有明显的差别。在含有海藻酸盐的悬浮液中加入钙离子，固化了下相-膜复合体。制备的样品用四氧化三和醋酸铀酰染色，进行透射电子显微镜观察。最值得注意的发现是：(1)表面活性剂确实吸附在气泡表面，并形成了亲奥斯气的衬层。纯DPPC膜不能被视觉化。(2)特定表面活性剂膜的独特结构取决于主体相中表面活性剂的组成和浓度，以及膜在形成后是否被压缩。薄膜表现出异质性，并与界面膜形成频繁的泡状和多片状的膜段。这些特征在通过吸附形成薄膜时已经可以看到，但在薄膜压缩后更容易出现多层片断。(3)成膜率、膜的可压缩性和膜压缩所获得的最小表面张力似乎与吸附形成的膜的结构有关，而吸附形成膜的结构又与形成膜的表面活性剂悬浮液的浓度有关。所见的表面活性物质可能对表面活性物质在空气-流体界面的表面性质和机械稳定性很重要。(C)2005 Elsevier B.V.保留所有权利。
Phospholipid films can be preserved in vitro when adsorbed to a solidifiable hypophase. Suspensions of natural surfactant, lipid extract surfactants, and artificial surfactants were added to a sodium alginate solution and filled into a captive bubble surfactometer (CBS). Surfactant film was formed by adsorption to the bubble of the CBS for functional tests. There were no discernible differences in adsorption, film compressibility or minimal surface tension on quasi-static or dynamic compression for films formed in the presence or absence of alginate in the subphase of the bubble. The hypophase-film complex was solidified by adding calcium ions to the suspension with the alginate. The preparations were stained with osmium tetroxide and uranyl acetate for transmission electron microscopy. The most noteworthy findings are: (1) Surfactants do adsorb to the surface of the bubble and form osmiophilic lining layers. Pure DPPC films could not be visualized. (2) A distinct structure of a particular surfactant film depends on the composition and the concentration of surfactant in the bulk phase, and on whether or not the films are compressed after their formation. The films appear heterogeneous, and frequent vesicular and multi-lamellar film segments are seen associated with the interfacial films. These features are seen already upon film formation by adsorption, but multi-lamellar segments are more frequent after film compression. (3) The rate of film formation, its compressibility, and the minimum surface tension achieved on film compression appear to be related to the film structure formed on adsorption, which in turn is related to the concentration of the surfactant suspension from which the film is formed. The osmiophilic Surface associated surfactant material seen is likely important for the surface properties and the mechanical stability of the surfactant film at the air-fluid interface. (c) 2005 Elsevier B.V. All rights reserved.