MELT TRANSITION AND STRUCTURE OF MEIBOMIAN LIPIDS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 睑板脂是泪膜最外层的主要成分，泪膜是保护眼睛表面的膜。它们由多种脂质物质组成，其中大多数是长链蜡酯、胆固醇酯和脂肪酸。因为它形成与空气的界面，所以脂质层的物理和化学性质被认为对泪膜稳定性有影响。我们有兴趣探索具有稳定泪膜的个体和患有干眼病（不稳定泪膜）的患者的睑板膜脂质的结构。对睑板腺脂质单层的研究表明，这些脂质的机械性质对温度非常敏感。我们希望将这些结果与晶体结构从25 ℃到熔融转变的变化联系起来，这将表明脂质的熔融温度。在某些形式的干眼病中，这些脂质的组成与无症状个体不同。如果熔化温度与体温相比显著变化，则脂质扩散的能力和脂质层的机械性质可能以泪膜变得不稳定的方式改变。本研究的目的是了解固有的晶体结构的Meibum从？正常吗和干眼症受试者作为温度的函数。我们希望这样的研究将有助于了解哪些特性促进泪膜的稳定性，它们如何随疾病而变化，以及如何为患有干眼症的个体恢复。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Meibomian lipids are the major component of the outermost layer of the tear film, the film that protects the surface of the eye. They are composed of a wide variety of lipid species, the majority of which are long chain wax esters, cholesterol esters and fatty acids. Because it forms the interface with air, the physical and chemical properties of the lipid layer are believed to be influential in tear film stability. We are interested in exploring the structure of Meibomian lipids from individuals with stable tear films and patients with dry eye disease (unstable tear films). Studies of Meibomian lipid monolayers have shown the mechanical properties of these lipids to be quite responsive to temperature. We would like to link these results to changes in the crystalline structure from 25¿C through the melting transition, which will indicate the melt temperature of the lipids. In some forms of dry eye disease the composition of these lipids is different than asymptomatic individuals. If the melt temperature changes significantly compared to body temperature, the ability of the lipids to spread and the mechanical properties of the lipid layer may be modified in such a way that the tear film becomes unstable. The goal of this study is to understand the inherent crystalline structure of Meibum from ?normal? and dry eye subjects as a function of temperature using small angle x-ray scattering. We hope that such studies will contribute to an understanding of which properties promote stability in the tear film, how they change with disease, and how they can be restored for individuals suffering from dry eye.