Research on the potential treatment of degenerative osteoarthritis by thiol-modified hyaluronic acidWEI

Chang-zheng; WU Yi; SONG Rui-rui; JIANG Li-xia

doi:10.3969/j.issn.2095-252X.2015.11.006

Abstract：Objective To synthesize a thiol modiifed hyaluronic acid with a certain ability of scavenging free radicals and to provide theory basis for the clinical treatment of osteoarthritis.Methods Sodium hyaluronic acid ( HA ) as raw material, 1- ( 3-dimethylaminopropyl ) -3- ethylcarbodiimide hydrochloride ( EDC ) was used to activate the carboxyl of HA and cystamin dihydrochloride was introduced to crosslink the HA hydrogel. Subsequently, dithiothreitol ( DTT ) was used to deoxidize the disulifde linkage into thiol and the thiol-HA was achieved.Results The thiol content of thiol-HA was 24.19%. The reducing capacity, the rate of hydroxyl radical scavenging and the rate of superoxide anion clearance were chosen to evaluate the antioxidant activities of the thiol-HA. The experimental results showed that the reducing force of the thiol-modiifed HA was equivalent with ( 4.15±0.21 ) % of vitamin C at the same concentration. Meanwhile, the concentration of the thiol-HA at 50% of the hydroxyl free radical scavenging was about 5 mg / ml. 10 mg / ml of the sample was added, the oxidation rate of pyrogallol was decreased to 20% of its autoxidation rate (P<0.05 ).Conclusions The articular cartilage is well lubricated by the injection of hyaluronic acid. Better oxidation resistance is achieved by the modiifcation of thiol. As a hydrogen donor, free radicals are quenched by thiol compounds which are oxidized to stable disulfide bond without chain reaction. In this research, sodium hyaluronate is modiifed by thiol with its oxidation resistance, therefore a certain antioxidant property is achieved with the ability of scavenging free radicals. And a theory basis is provided for the further clinical application.