Work

Supramolecular synergy in the boundary lubrication of synovial joints

Year: 2015

Type: article

Abstract: Hyaluronan, lubricin and phospholipids, molecules ubiquitous in synovial joints, such as hips and knees, have separately been invoked as the lubricants responsible for the remarkable lubrication of articular cartilage; but alone, these molecules cannot explain the extremely low friction at the high pressures of such joints. We find that surface-anchored hyaluronan molecules complex synergistically with phosphatidylcholine lipids present in joints to form a boundary lubricating layer, which, with coefficient of friction μ≈0.001 at pressures to over 100 atm, has a frictional behaviour resembling that of articular cartilage in the major joints. Our findings point to a scenario where each of the molecules has a different role but must act together with the others: hyaluronan, anchored at the outer surface of articular cartilage by lubricin molecules, complexes with joint phosphatidylcholines to provide the extreme lubrication of synovial joints via the hydration-lubrication mechanism.

Source: Nature Communications

DOI: 10.1038/ncomms7497

Authors: Jasmine Seror, Linyi Zhu, Ronit Goldberg, Anthony J. Day, Jacob Klein

Institutions: Weizmann Institute of Science, Chinese Academy of Sciences, Institute of Chemistry, Wellcome Centre for Cell-Matrix Research, University of Manchester

Language: English

Topic: Lubricants and Their Additives

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $5,719

Funders: Wellcome Trust, National Natural Science Foundation of China, Israel Science Foundation