Enriched Gellan Gum hydrogel as visco-supplement.

Viscosupplementation, i.e. intra-articular injection of hyaluronic acid derivatives, is considered as the most effective treatment for patients with mild to moderate osteoarthritis. Even if hyaluronic acid is still considered as the gold standard, research is now focusing on the development of new products with enhanced injectability and yet reasonable viscoelastic behavior for OA treatment. A Gellan Gum (GG) hydrogel was synthesized and coated with crosslinked polyvinyl alcohol (PVA) to protect the polysaccharide from degradation during sterilization and improve its performance for the foreseen application. Thermal analyses indicated that mixed hydrogel showed a higher degree of structuring than the bare polysaccharide core without losing its swelling properties, thanks to the hydrophylicity of both coating and cross-linking agent. The PVA coating increased elastic and viscous moduli of the polysaccharide core conferring it a higher resistance to shear and compression and better thixotropic properties. Despite the double crosslinking, hydrogel was injectable. Cytocompatibility towards chondrocytes was verified.