Hybrid complexes of high and low molecular weight: evaluation using an in vitro model of osteoarthritis.

Hyaluronan (HA) is central in joint and cartilage functions and to restore synovial fluid viscosity. In patients with osteoarthritis (OA), molecular weight (MW) and concentration of hyaluronic acid (HA) are reduced, diminishing joint lubrication. IL-1β treatment was used to mimic osteoarthritis in a chondrocytes based in vitro model. The aim of our research, using this model and human chondrocytes was to assess the anti-inflammatory effect of H/L-HA hybrid complexes (SINOVIAL-HL®) in comparison with HA at high (H-HA) and low molecular weight (L-HA) separately used, through the evaluation of specific biomarkers involved in cartilage degradation and correlated to osteoarthritis. Specifically, TNF-α and IL-6 mRNA were evaluated by qRT-PCR. Cytokines levels were measured using Bio-plex assays and COMP-2 through immunofluorescence staining and western blot. H/L-HA significantly reduced inflammation biomarkers respect to both L-HA or H-HA separately considered at transcriptional and protein level.