Achieving hemostasis in anticoagulated patients is an increasingly important clinical issue. Poly-N-acetylglucosamine (pGlcNAc) nanofibers activate platelets by β3 subunit (CD61) and the von Willebrand receptor GP1b (CD42b) integrin signaling for generation of a prothrombotic surface membrane. Recombinant coagulation factor VIIa (rFVIIa) functions in hemophilia A and B by catalyzing formation of the Xa/Va complex on the surface of activated platelets. These observations suggest that pGlcNAc nanofibers may amplify the activity of rFVIIa in hemophilic blood