| Autor: |
Sun K; Materials Science and Engineering Department, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801., Shoaib T; Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830., Rutland MW; KTH Royal Institute of Technology, Department of Chemistry, Stockholm SE-100 44, Sweden; School of Chemistry, University of New South Wales, Sydney 2052, Australia; Laboratoire de Tribologie et Dynamique des Systèmes, École Centrale de Lyon, Lyon 69130, France; and Bioeconomy and Health, Materials and Surface Design, RISE Research Institutes of Sweden, Stockholm, Sweden., Beller J; University of Tennessee, Knoxville, Tennessee 37996., Do C; Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830., Espinosa-Marzal RM; Materials Science and Engineering Department, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801. |
| Abstrakt: |
Interactions between molecules in the synovial fluid and the cartilage surface may play a vital role in the formation of adsorbed films that contribute to the low friction of cartilage boundary lubrication. Osteoarthritis (OA) is the most common degenerative joint disease. Previous studies have shown that in OA-diseased joints, hyaluronan (HA) not only breaks down resulting in a much lower molecular weight (MW), but also its concentration is reduced ten times. Here, we have investigated the structural changes of lipid-HA complexes as a function of HA concentration and MW to simulate the physiologically relevant conditions that exist in healthy and diseased joints. Small angle neutron scattering and dynamic light scattering were used to determine the structure of HA-lipid vesicles in bulk solution, while a combination of atomic force microscopy and quartz crystal microbalance was applied to study their assembly on a gold surface. We infer a significant influence of both MW and HA concentrations on the structure of HA-lipid complexes in bulk and assembled on a gold surface. Our results suggest that low MW HA cannot form an amorphous layer on the gold surface, which is expected to negatively impact the mechanical integrity and longevity of the boundary layer and could contribute to the increased wear of the cartilage that has been reported in joints diseased with OA. |
