Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Synergies in Biolubrication
KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The objective of this thesis was to advance understanding in the field of biolubrication, finding inspiration from the human synovial joints. This was addressed by investigating the association of key biolubricants and the resulting lubrication performance. Techniques employed during the course of this work were Atomic force microscopy (AFM), Quartz crystal microbalance with dissipation monitoring (QCM-D), X-ray reflectivity (XRR).

Key synovial fluid and cartilage components like dipalmitoylphosphatidylcholine (DPPC), hyaluronan (HA), lubricin, and cartilage oligomeric matrix protein (COMP) have been used in the investigations. Focus was towards two lubrication couples; DPPC-hyaluronan and COMP-lubricin. DPPC-hyaluronan mixtures were probed on hydrophilic silica surfaces and COMP-lubricin association structures were explored on weakly hydrophobic poly (methyl methacrylate) (PMMA) surfaces.

Investigations of the COMP-lubricin pair revealed that individually these components are unable to reach desired lubrication. However in combination, COMP facilitates firm attachment of lubricin to the PMMA surface in a favourable confirmation that imparts low friction coefficient.

DPPC and hyaluronan combined impart lubrication advantage over lone DPPC bilayers. Hyaluronan provides a reservoir of DPPC on the surface and consequently self-healing ability.

Other factors like temperature, presence of calcium ions, molecular weight of hyaluronan, and pressure were also explored. DPPC bilayers at higher temperature had higher load bearing capacity. Association between DPPC Langmuir layers and hyaluronan was enhanced in the presence of calcium ions, and lower molecular weight hyaluronan had a stronger tendency to bind to DPPC. At high pressures, DPPC-hyaluronan layers were more stable compared to lone DPPC bilayers.

Place, publisher, year, edition, pages
Sweden: KTH Royal Institute of Technology, 2017. , p. 66
Series
TRITA-CHE-Report, ISSN 1654-1081
Keyword [en]
Biolubrication, Synergies, Adsorption, Surface Force, Friction, Load Bearing Capacity, Self Healing, Phospholipids, DPPC, Hyaluronan, COMP, Lubricin, QCM-D, AFM, XRR.
National Category
Chemical Sciences
Research subject
Chemistry
Identifiers
URN: urn:nbn:se:kth:diva-201219ISBN: 978-91-7729-268-5 (print)OAI: oai:DiVA.org:kth-201219DiVA: diva2:1073157
Public defence
2017-03-17, Kollegiesalen, KTH, Brinellvägen 8, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20170210

Available from: 2017-02-10 Created: 2017-02-09 Last updated: 2017-02-13Bibliographically approved
List of papers
1. Molecular synergy in biolubrication: The role of cartilage oligomeric matrix protein (COMP) in surface-structuring of lubricin
Open this publication in new window or tab >>Molecular synergy in biolubrication: The role of cartilage oligomeric matrix protein (COMP) in surface-structuring of lubricin
Show others...
(English)Manuscript (preprint) (Other academic)
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-156655 (URN)
Note

QCR 20170221

Available from: 2014-12-02 Created: 2014-12-02 Last updated: 2017-02-21Bibliographically approved
2. Lubrication synergy: Mixture of hyaluronan and dipalmitoylphosphatidylcholine (DPPC) vesicles
Open this publication in new window or tab >>Lubrication synergy: Mixture of hyaluronan and dipalmitoylphosphatidylcholine (DPPC) vesicles
Show others...
2017 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 488, p. 225-233Article in journal (Refereed) Published
Abstract [en]

Phospholipids and hyaluronan have been implied to fulfil important roles in synovial joint lubrication. Since both components are present in synovial fluid, self-assembly structures formed by them should also be present. We demonstrate by small angle X-ray scattering that hyaluronan associates with the outer shell of dipalmitoylphophatidylcholine (DPPC) vesicles in bulk solution. Further, we follow adsorption to silica from mixed hyaluronan/DPPC vesicle solution by Quartz Crystal Microbalance with Dissipation measurements. Atomic Force Microscope imaging visualises the adsorbed layer structure consisting of non-homogeneous phospholipid bilayer with hyaluronan/DPPC aggregates on top. The presence of these aggregates generates a long-range repulsive surface force as two such surfaces are brought together. However, the aggregates are easily deformed, partly rearranged into multilayer structures and partly removed from between the surfaces under high loads. These layers offer very low friction coefficient (<0.01), high load bearing capacity (approximate to 23 MPa), and self-healing ability. Surface bound DPPC/hyaluronan aggregates provide a means for accumulation of lubricating DPPC molecules on sliding surfaces.

Place, publisher, year, edition, pages
Elsevier, 2017
Keyword
Dipalmitoylphosphatidylcholine (DPPC), Hyaluronan, Adsorption, Self-assembly, QCM-D, AFM imaging, Surface forces, Friction, Lubrication, Small-angle X-ray scattering
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-199458 (URN)10.1016/j.jcis.2016.10.091 (DOI)000389785500025 ()2-s2.0-84994491737 (Scopus ID)
Note

QC 20170123

Available from: 2017-01-23 Created: 2017-01-09 Last updated: 2017-11-29Bibliographically approved
3. The effect of temperature on supported dipalmitoylphosphatidylcholine (DPPC) bilayers: Structure and lubrication performance
Open this publication in new window or tab >>The effect of temperature on supported dipalmitoylphosphatidylcholine (DPPC) bilayers: Structure and lubrication performance
Show others...
2015 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 445, p. 84-92Article in journal (Refereed) Published
Abstract [en]

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.

Keyword
Phospholipid bilayer, DPPC, X-ray reflectivity, AFM, Surface forces, Friction, Lubrication, Load bearing capacity
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-156653 (URN)10.1016/j.jcis.2014.12.042 (DOI)000350006700011 ()25596372 (PubMedID)2-s2.0-84921024640 (Scopus ID)
Funder
Swedish Research Council, B0330901
Note

QC 20150409. Updated from manuscript to article in journal.

Available from: 2014-12-02 Created: 2014-12-02 Last updated: 2017-12-05Bibliographically approved
4. Structure of DPPC-hyaluronan interfacial layers - effects of molecular weight and ion composition
Open this publication in new window or tab >>Structure of DPPC-hyaluronan interfacial layers - effects of molecular weight and ion composition
Show others...
2016 (English)In: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 12, no 3, p. 729-740Article in journal (Refereed) Published
Abstract [en]

Hyaluronan and phospholipids play an important role in lubrication in articular joints and provide in combination with glycoproteins exceptionally low friction coefficients. We have investigated the structural organization of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) Langmuir layers at the solution-air interface at different length scales with respect to the adsorption of hyaluronan (HA). This allows us to assemble a comprehensive picture of the adsorption and the resulting structures, and how they are affected by the molecular weight of HA and the presence of calcium ions. Brewster angle microscopy and grazing incident diffraction were used to determine the lateral structure at the micro- and macro scale. The data reveals an influence of HA on both the macro and micro structure of the DPPC Langmuir layer, and that the strength of this effect increases with decreasing molecular weight of HA and in presence of calcium ions. Furthermore, from X-ray reflectivity measurements we conclude that HA adsorbs to the hydrophilic part of DPPC, but data also suggest that two types of interfacial structures are formed at the interface. We argue that hydrophobic forces and electrostatic interactions play important rules for the association between DPPC and HA. Surface pressure area isotherms were used to determine the influence of HA on the phase behavior of DPPC while electrophoretic mobility measurements were used to gain insight into the binding of calcium ions to DPPC vesicles and hyaluronan.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2016
National Category
Materials Engineering Chemical Sciences Physical Sciences
Identifiers
urn:nbn:se:kth:diva-183346 (URN)10.1039/c5sm01708d (DOI)000369746800010 ()26508354 (PubMedID)2-s2.0-84954134754 (Scopus ID)
Note

QC 20160307

Available from: 2016-03-07 Created: 2016-03-07 Last updated: 2017-11-30Bibliographically approved
5. The influence of hyaluronan on the structure of a DPPC-bilayer under high pressures
Open this publication in new window or tab >>The influence of hyaluronan on the structure of a DPPC-bilayer under high pressures
Show others...
2016 (English)In: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 142, p. 230-238Article in journal (Refereed) Published
Abstract [en]

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.

Keyword
Lubrication, Synovial joint, Vesicle fusion, Supported DPPC bilayer, Hyaluronan, High pressure, X-ray reflectivity
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-187770 (URN)10.1016/j.colsurfb.2016.02.040 (DOI)000375169600028 ()26954090 (PubMedID)
Funder
EU, FP7, Seventh Framework Programme, 312284
Note

QC 20160530

Available from: 2016-05-30 Created: 2016-05-30 Last updated: 2017-11-30Bibliographically approved

Open Access in DiVA

fulltext(2613 kB)80 downloads
File information
File name FULLTEXT01.pdfFile size 2613 kBChecksum SHA-512
02210be60d5d63a153d393254de3389ad0927427e385168e8b727f2ede39089546e8a79ee46224216f0f1acb134472db00423e722852c960ca61339ae35a8cb4
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Raj, Akanksha
By organisation
Surface and Corrosion Science
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 80 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 262 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf