Effects of hyaluronan on proteoglycan content of osteoarthritic chondrocytes in vitro

Purpose: To investigate the effect of hyaluronic acid (HA) on proteoglycan (PG) concentration in alginate cultures of human osteoarthritic chondrocytes and to analyze whether HA exhibit anti-degradative effects in the presence of the cytokine IL-1β. Methods: Cartilage samples from ten patients with osteoarthritis of the knee were harvested and chondrocytes were cultivated in alginate beads. Four groups were cultured: control group with and without IL-1β (500 pg/ml) and HA group ( 100 μg/ ml ) with and without IL-1β (500 pg/ml). PG concentration was estimated by a dimethylmethylene blue assay. To assess cell proliferation, we measured DNA content fluorometrically. Results: The proliferation rate (DNA) was unchanged in all culture groups. In the control-group PG/ DNA ( ng/ ng) concentration was 27.1±7.2. Supplementation of the medium with HA decreased PG concentration to 25.3±6.9 (p