Thrombin generation. (A) PPXbd and (B) generation 1.0 dendrimer delay thrombin generation in human plasma containing activated platelets. Real-time thrombin generation in plasma was quantified using calibrated automated thrombogram assays (Thrombinoscope; Diagnostica Stago). PPXbd (500 μg/mL), 20 μg/mL dendrimer, or saline was added to freshly drawn, citrated human blood, from which platelet-rich plasma was prepared and the platelet concentration adjusted to 150 000/μL. To some platelet-rich plasmas, TRAP was added at 10μM to activate platelets. After 5 minutes, FluCa reagent (fluorogenic substrate + CaCl₂) was added and thrombin generation was quantified. Parallel assays were performed on the same platelet-rich plasmas not pretreated with TRAP, but in which clotting was triggered using FluCa reagent that also contained 5pM tissue factor (TF). Thrombin generation parameters are plotted as mean ± SE (for 5 donors assayed in triplicate). Indicated P values are from paired t tests with and without inhibitor.