Biophysical properties of tear film lipid layer I. Surface tension and surface rheology
Biophysical properties of tear film lipid layer I. Surface tension and surface rheology
复制标题
泪膜脂质层的生物物理特性 I. 表面张力和表面流变学
DOI：
10.1016/j.bpj.2021.12.033
复制
发表时间：
2022
影响因子：
3.4
通讯作者：
Zuo, Yi Y.
中科院分区：
文献类型：
--
作者：
Xu, Xiaojie;Li, Guangle;Zuo, Yi Y.
泪膜脂质层（TFLL）是泪膜的最外层。它通过降低表面张力和延迟水层的蒸发在稳定泪膜方面起着至关重要的作用。TFLL的功能障碍导致功能障碍性泪液综合征，其中干眼病（DED）是最普遍的眼病，影响10%-30%的世界人口。迄今为止，除了缓解干眼症症状的治疗外，仍然缺乏治疗DED的有效治疗干预措施。因此，迫切需要了解TFLL的生物物理特性，长期目标是开发有效管理DED的翻译解决方案。在这里，我们研究了人工TFLL的组成功能的相关性，在生理相关的条件下，使用一种新的实验方法，称为约束液滴表面测量。该人工TFLL由40%油酸二十二烷酯和40%油酸胆固醇酯（分别代表天然TFLL中最丰富的蜡酯和胆固醇酯）以及15%磷脂酰胆碱和5%棕榈酸-9-羟基硬脂酸（PAHSA）（代表天然TFLL中两种主要的极性脂质类别）组成。我们的研究表明，磷脂在TFLL中的主要生物物理功能是降低表面张力，而PAHSA的主要功能是优化TFLL的流变特性。这些发现对于更好地理解TFLL的生理和生物物理功能具有新的意义，并可能为DED的治疗提供新的翻译见解。
Tear film lipid layer (TFLL) is the outmost layer of the tear film. It plays a crucial role in stabilizing the tear film by reducing surface tension and retarding evaporation of the aqueous layer. Dysfunction of the TFLL leads to dysfunctional tear syndrome, with dry eye disease (DED) being the most prevalent eye disease, affecting 10%–30% of the world population. To date, except for treatments alleviating dry eye symptoms, effective therapeutic interventions in treating DED are still lacking. Therefore, there is an urgent need to understand the biophysical properties of the TFLL with the long-term goal to develop translational solutions in effectively managing DED. Here, we studied the composition-function correlations of an artificial TFLL, under physiologically relevant conditions, using a novel experimental methodology called constrained drop surfactometry. This artificial TFLL was composed of 40% behenyl oleate and 40% cholesteryl oleate, representing the most abundant wax ester and cholesteryl ester in the natural TFLL, respectively, and 15% phosphatidylcholine and 5% palmitic-acid-9-hydroxy-stearic-acid (PAHSA), which represent the two predominant polar lipid classes in the natural TFLL. Our study suggests that the major biophysical function of phospholipids in the TFLL is to reduce the surface tension, whereas the primary function of PAHSA is to optimize the rheological properties of the TFLL. These findings have novel implications in better understanding the physiological and biophysical functions of the TFLL and may offer new translational insight to the treatment of DED.