Interfacial properties of avian stratum corneum monolayers investigated by Brewster angle microscopy and vibrational sum frequency generation

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Ellen M. Adams - , Ohio State University (Author)
  • Alex M. Champagne - , University Southern Indiana (Author)
  • Joseph B. Williams - , Ohio State University (Author)
  • Heather C. Allen - , Ohio State University (Author)

Abstract

The outermost layer of skin, the stratum corneum (SC), contains a complex mixture of lipids, which controls the rate of cutaneous water loss (CWL) in reptiles, mammals, and birds. However, the molecular structure of SC lipids and how molecular configurations influence CWL is poorly understood. Here, the organization and structure of SC lipids extracted from birds were investigated by means of Langmuir films. Properties of lipids from the SC of arid and semi-arid adapted larks, known to have a low CWL, were compared with lipids extracted from the SC of mesic lark species with higher CWL to gain insight into how structure impacts CWL. Film properties were probed with surface pressure-area isotherms, Brewster angle microscopy (BAM), and vibrational sum frequency generation (VSFG). Results indicate organization and ordering of SC lipids in the arid-adapted hoopoe lark was vastly different from all other species, forming a miscible, rigid monolayer, whereas monolayers from semi-arid and mesic species were immiscible and disordered. Probing of interfacial water structure reveals that film morphology determines organization of water molecules near the monolayer; monolayers with a porous morphology had an increased population of water molecules that are weakly hydrogen-bonded. In general, CWL appears related to the miscibility and ordering of lipid components within the SC, as well as the ability of these lipids to interact with water molecules. From a broader perspective, CWL in larks appears linked to both the SC lipid composition and the aridity of the species’ environment.

Details

Original languageEnglish
Pages (from-to)1-9
Number of pages9
JournalChemistry and Physics of Lipids
Volume208
Publication statusPublished - Nov 2017
Peer-reviewedYes
Externally publishedYes

External IDs

PubMed 28807615
ORCID /0000-0002-8120-8553/work/158306267

Keywords

Keywords

  • Birds, Brewster angle microscopy, Langmuir monolayers, Stratum corneum, Vibrational sum frequency generation, Water loss