title: Hyaluronic acid hydrogel in the treatment of osteoarthritis.
abstract: In order to overcome the problem of rapid clearance of the polysaccharide hyaluronic acid (Hyal) in the treatment of osteoarthritis (OA), a 50% cross-linked Hyal hydrogel (Hyal 50%) was synthesised. The 50% refers to the amount of COOH groups of the polysaccharide involved in the cross-linking reaction. i.e. 50% of the total amount. The rheological behaviour of the Hyal 50% hydrogel, and in particular the possibility to inject it through a needle, was studied. The results obtained demonstrated that the hydrogel injected through the needle still behaved like a gel, although it showed a reduction of the dynamic moduli. The most appropriate sterilisation technique for this kind of hydrogel was also evaluated. Liophilised Hyal 50% samples were sterilised by steam, Ethylene Oxide (EtO) and gamma-rays. EtO and gamma-rays did not modify the characteristics of the hydrogel in terms of swellability and morphology. Lastly, the in vivo effect of Hyal 50% hydrogel in the treatment of chondral defect in rabbit knee was also studied. The results obtained showed the Hyal 50% injections improved chondrocytes density and matrix appearance. Furthermore, the permanence in situ of the hydrogel was longer than that of the linear Hyal.
mesh_terms: D016475:3T3 Cells; D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D001672:Biocompatible Materials; D002358:Cartilage, Articular / Q000166:cytology; D003432:Cross-Linking Reagents; D005027:Ethylene Oxide / Q000378:metabolism; D006820:Hyaluronic Acid / Q000494:pharmacology*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry / Q000494:pharmacology*; D051379:Mice; D008855:Microscopy, Electron, Scanning; D010003:Osteoarthritis / Q000188:drug therapy*; D011134:Polysaccharides / Q000737:chemistry; D011817:Rabbits; D013997:Time Factors
chemical_list: D000276:Adjuvants, Immunologic; D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D011134:Polysaccharides; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D006820:Hyaluronic Acid; D005027:Ethylene Oxide