Lactose-Modified Hyaluronic Acid Molecule Attenuates In Vitro Chondrocyte Inflammation

Background: Osteoarthritis (OA) is a chronic degenerative whole joint disease characterized by cartilage breakdown and inflammation. Galectin-3 (Gal-3), a β-galactoside-binding lectin secreted into the extracellular space, binds to glycosylated components of the extracellular matrix (ECM), modulating cell–matrix interactions and inflammation. This study aims to evaluate the anti-inflammatory effects of Hylach®, a hyaluronic acid (HA) derivative conjugated with lactose-based residues that bind Gal-3, on in vitro inflamed primary human chondrocytes. Methods: Chondrocyte viability, after both Hylach® and HA treatments at different concentrations was assessed using the MTT assay. Two-dimensional and 3D cell cultures exposed to the conditioned medium (CM) of activated U937 monocytes and subsequently treated with Hylach or HA, were analyzed for the expression of IL-1β, IL-6, TNF-α, and Gal-3 at different time points (4, 10, and 24 h). Results: HA and Hylach® did not affect cell viability at any of the tested concentrations. Both molecules reduced the overexpression of Gal-3 and pro-inflammatory molecules in 2D inflamed cell cultures, at both gene and protein levels. Notably, IL-1β, IL-6 and Gal-3 showed a more pronounced inhibitory effect at 4 h, with Hylach demonstrating a stronger reduction compared to native HA. Moreover, in inflamed 3D chondrocyte cultures, Hylach® but not HA, significantly reduced IL-1β, TNF-α and Gal-3 gene expression. Conclusions: Hylach® exerts an early and more potent anti-inflammatory effect in inflamed 2D and 3D chondrocyte cultures when compared to HA. These findings suggest that targeting Gal-3 through selective HA derivatives may represent a promising strategy for modulating both inflammation and matrix remodelling in OA.