title: Comparative study of hyaluronic derivatives: rheological behaviour, mechanical and chemical degradation.
abstract: Depolymerisation by oxytetracycline (OTC) as well as the progressive cleavage of hyaluronic acid induced by ultrasound was investigated in nine commercially available hyaluronic polymers. Sample solutions differed in molecular weight, from 500 to 7000 kDa, and in their source. The hyaluronic acid concentration in each sample was analysed by HPLC. The concentration range was over 8.39-10.18 mg ml(-1) in samples with a nominal concentration of 1%, and 14.05 mg ml(-1) in one sample with a nominal concentration of 1.5%. It was found that stability was dependent on both molecular weight and the concentration of the samples. The rheological parameters n (power law index) and K (consistency coefficient) were good predictors regarding the degradation behaviour. Although many factors are involved in obtaining a therapeutic response, the results obtained in this work support the notion that both mechanical and chemical degradation are reduced in hyaluronate solutions with low molecular weight, the final concentration of the product being a critical factor.
authors.affiliation: Department of Physiology, University of Leon, Leon 24071, Spain.
authors.forename: J G
authors.initials: JG
authors.lastname: Prieto
authors.forename: M M
authors.initials: MM
authors.lastname: Pulido
authors.forename: J
authors.initials: J
authors.lastname: Zapico
authors.forename: A J
authors.initials: AJ
authors.lastname: Molina
authors.forename: M
authors.initials: M
authors.lastname: Gimeno
authors.forename: P
authors.initials: P
authors.lastname: Coronel
authors.forename: A I
authors.initials: AI
authors.lastname: Alvarez
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002138:Calibration; D002845:Chromatography; D002851:Chromatography, High Pressure Liquid; D004548:Elasticity; D006820:Hyaluronic Acid / Q000737:chemistry*; D016014:Linear Models; D019563:Mechanics; D008970:Molecular Weight; D010118:Oxytetracycline / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D011312:Pressure; D012212:Rheology; D013010:Sonication; D013696:Temperature; D013997:Time Factors; D014783:Viscosity
chemical_list: D001672:Biocompatible Materials; D011108:Polymers; D006820:Hyaluronic Acid; D010118:Oxytetracycline