Molecular structure of interfacial human meibum films.
Meibum is the primary component of the tear film lipid layer. Thought to play a role in tear film stabilization, understanding the physical properties of meibum and how they change with disease will be valuable in identifying dry eye treatment targets. Grazing incidence X-ray diffraction and X-ray reflectivity were applied to meibum films at an air-water interface to identify molecular organization. At room temperature, interfacial meibum films formed two coexisting scattering phases with rectangular lattices and next-nearest neighbor tilts, similar to the Ov phase previously identified in fatty acids. The intensity of the diffraction peaks increased with compression, although the lattice spacing and molecular tilt angle remained constant. Reflectivity measurements at surface pressures of 18 mN/m and above revealed multilayers with d-spacings of 50 Å, suggesting that vertical organization rather than lateral was predominantly affected by meibum-film compression.
Chemical Engineering Department, Stanford University, California, USA.
Danielle L
DL
Leiske
Chad E
CE
Miller
Liat
L
Rosenfeld
Colin
C
Cerretani
Alexander
A
Ayzner
Binhua
B
Lin
Mati
M
Meron
Michelle
M
Senchyna
Howard A
HA
Ketelson
David
D
Meadows
Sruthi
S
Srinivasan
Lyndon
L
Jones
Clayton J
CJ
Radke
Michael F
MF
Toney
Gerald G
GG
Fuller
D005260:Female; D006801:Humans; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry*; D008537:Meibomian Glands / Q000737:chemistry* / Q000378:metabolism*; D014961:X-Ray Diffraction
D008055:Lipids