کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4032024 1262933 2011 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Lessons from the biophysics of interfaces: Lung surfactant and tear fluid
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی سیستم های حسی
پیش نمایش صفحه اول مقاله
Lessons from the biophysics of interfaces: Lung surfactant and tear fluid
چکیده انگلیسی

The purpose of this review is to provide insight into the biophysical properties and functions of tear fluid and lung surfactant – two similar fluids covering the epithelium of two distinctive organs. Both fluids form a layer-like structure that essentially comprise of an aqueous layer next to the epithelium and an anterior lipid layer at the air-water interface. The aqueous layers contain soluble proteins and metabolites, and they are responsible for the host defence system and nutrition of the organ. However, many proteins also interact with the lipid layer and are important for the surface-active function of the fluid film. The lipid layer of lung surfactant comprises mainly of phospholipids, especially phosphatidylcholines, and only small amounts of non-polar lipids, mainly cholesterol. In contrast, tear fluid lipid layer comprises of a mixture of polar and non-polar lipids. However, the relative proportion and the spectrum of different polar and non-polar lipids seem to be more extensive in tear fluid than in lung surfactant. The differing lipid compositions generate distinctive lipid layer structures. Despite the structural differences, these lipid layers decrease the surface tension of the air-water interface. The structure of the tear film lipid layer also minimises the evaporation of the tear fluid. In lung surfactant surface activity is crucial for the function of the organ, as the lipid layer prevents the collapse of the lung alveoli during the compression-expansion cycle of breathing. Similarly the tear film experiences a compression-expansion cycle during blinking. The dynamics of this cycle have been studied to a lesser extent and are not as clear as those of lung surfactant. The common structure and properties suggest a similar behaviour under rapid compression–expansion for both fluids.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Progress in Retinal and Eye Research - Volume 30, Issue 3, May 2011, Pages 204–215
نویسندگان
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