The effect of temperature on supported dipalmitoylphosphatidylcholine (DPPC) bilayers: Structure and lubrication performance
2015 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 445, 84-92 p.Article in journal (Refereed) Published
Phospholipids fulfill an important role in joint lubrication. They, together with hyaluronan and glycoproteins, are the biolubricants that sustain low friction between cartilage surfaces bathed in synovial fluid. In this work we have investigated how the friction force and load bearing capacity of 1,2-dipalmitoyl-snglycero-3-phosphocholine (DPPC) bilayers on silica surfaces are affected by temperature, covering the temperature range 25-52 degrees C. Friction forces have been determined utilizing the AFM colloidal probe technique, which showed that DPPC bilayers are able to provide low friction forces over the whole temperature interval. However, the load bearing capacity is improved at higher temperatures. We interpret this finding as being a consequence of lower rigidity and higher self-healing capacity of the DPPC bilayer in the liquid disordered state compared to the gel state. The corresponding structure of solid supported DPPC bilayers at the silica-liquid interface has been followed using X-ray reflectivity measurements, which suggests that the DPPC bilayer is in the gel phase at 25 degrees C and 39 degrees C and in the liquid disordered state at 55 degrees C. Well-defined bilayer structures were observed for both phases. The deposited DPPC bilayers were also imaged using AFM PealcForce Tapping mode, and these measurements indicated a less homogeneous layer at temperatures below 37 degrees C.
Place, publisher, year, edition, pages
2015. Vol. 445, 84-92 p.
Phospholipid bilayer, DPPC, X-ray reflectivity, AFM, Surface forces, Friction, Lubrication, Load bearing capacity
IdentifiersURN: urn:nbn:se:kth:diva-156653DOI: 10.1016/j.jcis.2014.12.042ISI: 000350006700011PubMedID: 25596372ScopusID: 2-s2.0-84921024640OAI: oai:DiVA.org:kth-156653DiVA: diva2:767632
FunderSwedish Research Council, B0330901
QC 20150409. Updated from manuscript to article in journal.2014-12-022014-12-022015-04-09Bibliographically approved