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Friction, lubrication, and polymer transfer between UHMWPE and CoCrMo hip‐implant materials: A fluorescence microscopy study
Author(s) -
Crockett Rowena,
Roba Marcella,
Naka Marco,
Gasser Beat,
Delfosse Daniel,
Frauchiger Vinzenz,
Spencer Nicholas D.
Publication year - 2008
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.32036
Subject(s) - materials science , quenching (fluorescence) , lubrication , composite material , tribology , synovial fluid , polymer , friction coefficient , fluorescence , optics , medicine , physics , alternative medicine , pathology , osteoarthritis
The friction coefficients of CoCrMo sliding against UHMWPE and CoCrMo were measured in solutions of albumin and synovial fluid containing fluorescently labeled albumin. No fluorescence could be observed on the CoCrMo disc following incubation in labeled albumin or after sliding against CoCrMo. This was due to quenching of the fluorophore by the metal and indicated that a protein film thicker than 10 nm was not formed on the surface. A more complicated behavior was observed for UHMWPE sliding against CoCrMo. For each lubricating solution and at each load, a bimodal distribution of steady‐state friction values was observed, the friction coefficient either remaining constant or decreasing during the early stages of the measurement. As no quenching of the fluorophores occurred on the UHMWPE surface, the fluorescence labeling method could be used to reveal polyethylene (PE) transfer and to show that it correlates with the friction coefficient: Low friction coefficients corresponded to a low density of PE spots on the CoCrMo surface. In addition, it was found that the friction coefficients for UHMWPE sliding against CoCrMo in synovial fluid were not significantly different from those in phosphate‐buffered saline (PBS), but that the addition of albumin to PBS did cause a significant increase in the friction coefficient. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009