Journal
CHEMISTRY AND PHYSICS OF LIPIDS
Volume 165, Issue 4, Pages 374-381Publisher
ELSEVIER IRELAND LTD
DOI: 10.1016/j.chemphyslip.2011.11.007
Keywords
Liposome; Surface force; Lubrication; Hydration
Categories
Funding
- European Research Council
- Israel Science Foundation
- Minerva Foundation at the Weizmann Institute
- Hebrew University
Ask authors/readers for more resources
In this paper we review recent work (Goldberg et al., 2011a,b) on a new use for phosphatidylcholine liposomes: as ultra-efficient boundary lubricants at up to the highest physiological pressures. Using a surface force balance, we have measured the normal and shear interactions as a function of surface separation between layers of hydrogenated soy phophatidylcholine (HSPC) small unilamellar vesicles (SUVs) adsorbed from dispersion, at both pure water and physiologically high salt concentrations of 0.15M NaNO3. Cryo-Scanning Electron Microscopy shows each surface to be coated by a close-packed HSPC-SUV layer with an over-layer of liposomes on top. The shear forces reveal strikingly low friction coefficients down to 2 x 10(-5) in pure water system or 6 x 10(-4) in the 150 mM salt system, up to contact pressures of at least 12 MPa (pure water) or 6 MPa (high salt), comparable with those in the major joints. This low friction is attributed to the hydration lubrication mechanism arising from rubbing of the highly hydrated phosphocholine-headgroup layers exposed at the outer surface of each liposome, and provides support for the conjecture that phospholipids may play a significant role in biological lubrication. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available