title: Some conceptual thoughts toward nanoscale oriented friction in a model of articular cartilage.
abstract: This work presents a conceptual framework as to how a deficit in the synovial-fluid content, exemplified by hyaluronan or any other amphiphilic species, is capable of decisively altering the complex lubrication and wear conditions observed clinically in articular cartilage. The effect is revealed in (non)stationary regimes if the cartilage is subjected to some normal periodic load, revealing over its exploitation time increasingly dissipative, in general entropy-addressing, characteristics. It can be hypothesized that a Grotthuss-type proton transport physiology-concerning mechanism in channel-like, phospholipid-water cartilage's articulating nanospaces will be responsible for the expression of the lubrication mode. The corresponding wear involving overall change is then manifested adequately in the stationary regime, and in a viable system-parametric correlation with its lubrication counterpart. Certain analytic formulae for the nanoscale oriented coefficient of friction, involving generically H-bonds breaking mechanism, and pointing to some local-viscosity context, have been proposed for fitting the experimental data and clinical observations involving proton management at articular cartilage surfaces.
authors.affiliation: University of Technology and Life Sciences, Institute of Mathematics and Physics, PL-85796 Bydgoszcz, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Gadomski
authors.forename: Piotr
authors.initials: P
authors.lastname: Bełdowski
authors.forename: J Miguel
authors.initials: JM
authors.lastname: Rubì
authors.forename: Wiesław
authors.initials: W
authors.lastname: Urbaniak
authors.forename: Wayne K
authors.initials: WK
authors.lastname: Augé
authors.forename: Ivan
authors.initials: I
authors.lastname: Santamarìa-Holek
authors.forename: Zenon
authors.initials: Z
authors.lastname: Pawlak
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000502:physiology*; D017276:Friction / Q000502:physiology; D006820:Hyaluronic Acid / Q000502:physiology*; D008954:Models, Biological; D013582:Synovial Fluid / Q000502:physiology*
chemical_list: D006820:Hyaluronic Acid
keywords: Articular-cartilage lubrication and wear; Hyaluronan; Proton conductance; Surface-active phospholipids