Accordingly, both aPTT and PT tests were performed to check the capacity of our C22G1 self-assembled dendrimers to reverse the effect of heparin (Figure 5d). The experimental clotting time of pure plasma was equal to 35.7 s according to the intrinsic (aPTT) assay and to 12.8 s when measured by the PT assay. When heparin was added to plasma, the clotting time reduced to ~0, as expected from the anticoagulant activity exerted by the polyanion. On further addition of C22G1 nanomicelles, however, although for some reasons still unknown the clotting time measured by the aPTT assay increased to 81.8 s, the PT assay yielded a clotting time of 13.1, very close to that of native plasma, supporting the concept that the self-assembled C22G1 dendrimers are endowed of functional heparin reversal in the most biologically relevant environment.