Role of neutral lipids in tear fluid lipid layer: Coarse-grained simulation study

Research output: Contribution to journalArticleScientificpeer-review

Researchers

  • Jelena Telenius
  • Artturi Koivuniemi
  • Pipsa Kulovesi
  • Juha M. Holopainen
  • Ilpo Vattulainen

Research units

  • Tampere University of Technology
  • VTT Technical Research Centre of Finland Ltd.
  • University of Helsinki
  • University of Southern Denmark

Abstract

Tear fluid lipid layer (TFLL) residing at the air-water interface of tears has been recognized to play an important role in the development of dry eye syndrome. Yet, the composition, structure, and mechanical properties of TFLL are only partly known. Here, we report results of coarse-grained simulations of a lipid layer comprising phospholipids, free fatty acids, cholesteryl esters, and triglycerides at the air-water interface to shed light on the properties of TFLL. We consider structural as well as dynamical properties of the lipid layer as a function of surface pressure. Simulations revealed that neutral lipids reside heterogeneously between phospholipids at relatively low pressures but form a separate hydrophobic phase with increasing surface pressure, transforming the initial lipid monolayer to a two-layered structure. When the model of TFLL was compared to a one-component phospholipid monolayer system, we found drastic differences in both structural and dynamical properties that explain the prominent role of neutral lipids as stabilizers of the TFLL. Based on our results, we suggest that neutral lipids are able to increase the stability of the TFLL by modulating its dynamical and structural behavior, which is important for the proper function of tear film.

Details

Original languageEnglish
Pages (from-to)17092-17100
Number of pages9
JournalLangmuir
Volume28
Issue number49
Publication statusPublished - 11 Dec 2012
MoE publication typeA1 Journal article-refereed

ID: 17914408