title: Rheopexy of synovial fluid and protein aggregation.
abstract: Bovine synovial fluid and albumin solutions of similar concentration are rheopectic (stress increases with time in steady shear). This unusual flow characteristic is caused by protein aggregation, and the total stress is enhanced by entanglement of this tenuous protein network with the long-chain polysaccharide sodium hyaluronate under physiological conditions. Neutron scattering measurements on albumin solutions demonstrate protein aggregation and all measurements are consistent with a weak dipolar attraction energy (of order 3kT) that is most likely augmented by hydrophobic interactions and/or disulfide bond formation between proteins. Protein aggregation appears to play an important role in the mechanical properties of blood and synovial fluid. We also suggest a connection between the observed rheopexy and the remarkable lubrication properties of synovial fluid.
authors.affiliation: The Pennsylvania State University, Department of Materials Science and Engineering and the Materials Research Institute, University Park, PA 16802, USA.
authors.forename: Katherine M N
authors.initials: KM
authors.lastname: Oates
authors.forename: Wendy E
authors.initials: WE
authors.lastname: Krause
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Jones
authors.forename: Ralph H
authors.initials: RH
authors.lastname: Colby
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000032:analysis / Q000737:chemistry*; D002417:Cattle; D008153:Lubrication; D046912:Multiprotein Complexes / Q000032:analysis / Q000737:chemistry; D012212:Rheology / Q000379:methods; D012710:Serum Albumin, Bovine / Q000032:analysis / Q000737:chemistry; D013582:Synovial Fluid / Q000737:chemistry*; D013997:Time Factors; D014783:Viscosity
chemical_list: D001798:Blood Proteins; D046912:Multiprotein Complexes; D012710:Serum Albumin, Bovine