Analysis of hyaluronic acid in synovial fluid by reversed-phase liquid chromatography

Quantitative analysis of hyaluronan in human synovial fluid using capillary electrophoresis

The glycosaminoglycan, hyaluronan, can be detected in human synovial fluid by capillary electrophoresis (CE). Variations in peak shape make this technique unsuitable for quantitative analysis of hyaluronan in raw synovial fluid. Quantitative analysis was achieved by hydrolysis of the polymeric hyaluronan to the tetrasaccharide by the action of testicular hyaluronidase and separation of the product using CE. A UV detector operating at 200 nm was used. The X-ray contrast material, omnipaque, a propriety aqueous solution of iohexol was used as internal standard. A second peak in the electropherogram of synovial fluid was quantified. The variation in concentrations of these two components correlate with the arthritic disease state of a joint.

Depolymerization reactions of hyaluronic acid in solution

Samples of microbial sodium hyaluronate were degraded by heating, ultrasonication ultraviolet (UV) and gamma-ray irradiation and enzymatic treatment. The weight-average molecular weight, Mw, of hyaluronate in 0.15 M NaCl and 0.06 M Na2HPO4 was determined by gel filtration with UV detection. The Mw of the degraded samples varied from 8 x 10(4) to 1.38 x 10(6). Depolymerization processes can be described by linear relationship (1/Mw)2 = f(t) in the case of ultrasonic treatment and by non-linear relationships in the cases of heating and UV irradiation at 257 nm. Gamma-ray irradiation and enzymatic treatment caused chemical degradation and depolymerization to oligosaccharides, respectively.

Assay of synovial fluid hyaluronic acid using high-performance liquid chromatography of hyaluronidase digests

A high-performance liquid chromatographic method for the determination of hyaluronic acid levels in synovial fluids has been developed. The hyaluronidase sample digests, containing an internal standard (benzoic acid), were separated on a reversed-phase octadecylsilyl column eluted with 0.01 M tetrabutylammonium phosphate-acetonitrile (83:17, v/v) at pH 7.35. The determination was made on 1:10 diluted samples, by using a calibration curve from 50 to 500 micrograms/ml of human umbilical cord hyaluronic acid. For validation, the synovial fluids were simultaneously analysed by this method and a radiometric method: a high correlation was found between the two (correlation coefficient 0.94). The proposed method can be used to determine specifically the high hyaluronic acid levels of synovial fluids without interferences from other glycosaminoglycans or non-steroidal anti-inflammatory drug treatment.