Article Metrics


Online attention

The Influence of Hyaluronan on the Structure of a DPPC − Bilayer under High Pressures

DOI: 10.1016/j.colsurfb.2016.02.040 DOI Help

Authors: Thomas Zander (Helmholtz-Zentrum Geesthacht) , D. C. Florian Wieland (Helmholtz-Zentrum Geesthacht) , Akanksha Raj (KTH Royal Institute of Technology) , Min Wang (KTH Royal Institute of Technology) , Benedikt Nowak (Fakultät Physik/DELTA) , Christina Krywka (Helmholtz-Zentrum Geesthacht) , Andra Dėdinaitė (KTH Royal Institute of Technology) , Per Martin Claesson (KTH Royal Institute of Technology) , Vasil M. Garamus (Helmholtz-Zentrum Geesthacht) , Andreas Schreyer (Helmholtz-Zentrum Geesthacht) , Regine Willumeit-römer (Helmholtz-Zentrum Geesthacht)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Colloids And Surfaces B: Biointerfaces , VOL 142 , PAGES 230–238

State: Published (Approved)
Published: June 2016
Diamond Proposal Number(s): 9856

Abstract: The superior lubrication properties of synovial joints have inspired many studies aiming at uncovering the molecular mechanisms which give rise to low friction and wear. However, the mechanisms are not fully understood yet, and, in particular, it has not been elucidated how the biolubricants present at the interface of cartilage respond to high pressures, which arise during high loads of joints. In this study we utilize a simple model system composed of two biomolecules that have been implied as being important for joint lubrication. It consists of a solid supported dipalmitoylphosphatidylcholin (DPPC) bilayer, which was formed via vesicles fusion on a flat Si wafer, and the anionic polysaccharide hyaluronan (HA). We first characterized the structure of the HA layer that adsorbed to the DPPC bilayers at ambient pressure and different temperatures using X-ray reflectivity (XRR) measurements. Next, XRR was utilized to evaluate the response of the system to high hydrostatic pressures, up to 2 kbar (200 MPa), at three different temperatures. By means of fluorescence microscopy images the distribution of DPPC and HA on the surface was visualized. Our data suggest that HA adsorbs to the headgroup region that is oriented towards the water side of the supported bilayer. Phase transitions of the bilayer in response to temperature and pressure changes were also observed in presence and absence of HA. Our results reveal a higher stability against high hydrostatic pressures for DPPC/HA composite layers compared to that of the DPPC bilayer in absence of HA.

Journal Keywords: Lubrication; Synovial joint; Vesicle fusion; Supported DPPC bilayer; Hyaluronan; High pressure; X-ray reflectivity

Subject Areas: Chemistry

Instruments: I07-Surface & interface diffraction

Added On: 25/02/2016 13:49

Discipline Tags:

Technical Tags: