Journal of Thrombosis and Thrombolysis

, Volume 35, Issue 1, pp 48–56

The effect of surface contact activation and temperature on plasma coagulation with an RNA aptamer directed against factor IXa

  • Anandi Krishnan
  • Erwin A. Vogler
  • Bruce A. Sullenger
  • Richard C. Becker
Article

Abstract

The anticoagulant properties of a novel RNA aptamer that binds FIXa depend collectively on the intensity of surface contact activation of human blood plasma, aptamer concentration, and its binding affinity for FIXa. Accordingly, anticoagulation efficiency of plasma containing any particular aptamer concentration is low when coagulation is strongly activated by hydrophilic surfaces compared to the anticoagulation efficiency in plasma that is weakly activated by hydrophobic surfaces. Anticoagulation efficiency is lower at hypothermic temperatures possibly because aptamer-FIXa binding decreases with decreasing temperatures. Experimental results demonstrating these trends are qualitatively interpreted in the context of a previously established model of anticoagulation efficiency of thrombin-binding DNA aptamers that exhibit anticoagulation properties similar to the FIXa aptamer. In principle, FIXa aptamer anticoagulants should be more efficient and therefore more clinically useful than thrombin-binding aptamers because aptamer binding to FIXa competes only with FX that is at much lower blood concentration than fibrinogen (FI) that competes with thrombin-binding aptamers. Our findings may have translatable relevance in the application of aptamer anticoagulants for clinical conditions in which blood is in direct contact with non-biological surfaces such as those encountered in cardiopulmonary bypass circuits.

Keywords

Factor IXa inhibition FIXa aptamer Activator surfaces Contact activation Coagulation Recalcification clot time 

Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  • Anandi Krishnan
    • 1
  • Erwin A. Vogler
    • 2
  • Bruce A. Sullenger
    • 3
  • Richard C. Becker
    • 1
    • 3
  1. 1.Duke Clinical Research InstituteDuke University Medical CenterDurhamUSA
  2. 2.Departments of Materials Science & Engineering and BioengineeringThe Pennsylvania State UniversityUniversity ParkUSA
  3. 3.Departments of Surgery and Medicine and Duke Translational Research InstituteDuke University Medical CenterDurhamUSA

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