Scale-Dependent Rheology of Synovial Fluid Lubricating Macromolecules.

Autor: Martin-Alarcon L; Biomedical Engineering Graduate Program, University of Calgary, Calgary, AB, T2N 1N4, Canada., Govedarica A; Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada., Ewoldt RH; Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA., Bryant SL; Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada., Jay GD; Department of Emergency Medicine - Warren Alpert Medical School & School of Engineering, Brown University, Providence, RI, 02912, USA., Schmidt TA; Biomedical Engineering Department, University of Connecticut Health Center, Farmington, CT, 06030, USA., Trifkovic M; Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB, T2N 1N4, Canada.
Jazyk: angličtina
Zdroj: Small (Weinheim an der Bergstrasse, Germany) [Small] 2024 May; Vol. 20 (21), pp. e2306207. Date of Electronic Publication: 2023 Dec 31.
DOI: 10.1002/smll.202306207
Abstrakt: Synovial fluid (SF) is the complex biofluid that facilitates the exceptional lubrication of articular cartilage in joints. Its primary lubricating macromolecules, the linear polysaccharide hyaluronic acid (HA) and the mucin-like glycoprotein proteoglycan 4 (PRG4 or lubricin), interact synergistically to reduce boundary friction. However, the precise manner in which these molecules influence the rheological properties of SF remains unclear. This study aimed to elucidate this by employing confocal microscopy and multiscale rheometry to examine the microstructure and rheology of solutions containing recombinant human PRG4 (rhPRG4) and HA. Contrary to previous assumptions of an extensive HA-rhPRG4 network, it is discovered that rhPRG4 primarily forms stiff, gel-like aggregates. The properties of these aggregates, including their size and stiffness, are found to be influenced by the viscoelastic characteristics of the surrounding HA matrix. Consequently, the rheology of this system is not governed by a single length scale, but instead responds as a disordered, hierarchical network with solid-like rhPRG4 aggregates distributed throughout the continuous HA phase. These findings provide new insights into the biomechanical function of PRG4 in cartilage lubrication and may have implications in the development of HA-based therapies for joint diseases like osteoarthritis.
(© 2023 The Authors. Small published by Wiley‐VCH GmbH.)
Databáze: MEDLINE
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