Sulfated hyaluronic acid as heparin-like material: physicochemical and biological characterization

Hyaluronic acid was partially sulfated and a polymer containing a precise number of sulfate groups for each repeating unit was prepared. The properties of this macromolecule in aqueous solution were studied at different pH levels by using potentiometric, viscosimetric techniques and were compared with that of the native hyaluronic acid, partially esterified hyaluronic acid and heparin. The influence of sulfate groups on the macromolecule is evident in the protonation constant and in the conformation of the polymer. This material exhibits an antithrombotic effect as evidenced by the lengthening of both the thrombin time and the whole blood clotting time. Moreover, the absence of hemolysis and the growth and shape of endothelial cells put in contact with the sulfated hyaluronic acid indicate that this polymer is a promising heparin-like compound.