Gellan sulfate selectively suppresses the activation of hemocoagulation factors XI and XII

In this study, gellan sulfate (GS), a novel anticoagulant, was prepared by mixing deacetylated gellan and the dimethylformamide/sulfur trioxide (DMF-SO3) complex; this complex was prepared by adding varying volumes of chlorosulfonic acid (ClSO3H) to DMF. The anticoagulant properties of GS were measured by determining the coagulation time, prothrombin time (PT), and activated partial thromboplastin time (aPTT) of normal whole blood samples and by analyzing the activation of hemocoagulation factors V, VIII, IX, X, and XII. We found that 0.04 mg/mL of GS with 40% sulfonation exhibits anticoagulant properties. GS selectively suppressed the activation of hemocoagulation factors XI and XII in the initial steps of the contact activation pathway. On the basis of our results, it can be concluded that the mechanism underlying the anticoagulation effects of GS was different from that of heparin. In addition, GS did not react with other hemocoagulation factors such as factors IX and X, and its activity was independent of antithrombin.