title: Hemocompatibility Comparison of Biomedical Grade Polymers Using Rabbit Thrombogenicity Model for Preparing Nonthrombogenic Nitric Oxide Releasing Surfaces.
abstract: Nitric oxide (NO) is an endogenous vasodilator as well as natural inhibitor of platelet adhesion/activation. Nitric oxide releasing (NOrel) materials can be prepared by doping an NO donor species, such as diazeniumdiolated dibutylhexanediamine (DBHD/N2O2), within a polymer coating. The inherent hemocompatibility properties of the base polymer can also influence the efficiency of such NO release coatings. In this study, four biomedical grade polymers were evaluated in a 4 h rabbit model of thrombogenicity for their effects on extracorporeal circuit thrombus formation and circulating platelet count. At the end of 4 h, Elast-Eon E2As was found to preserve 58% of baseline platelets versus 48, 40, and 47% for PVC/DOS, Tecophilic SP-60D-60, and Tecoflex SG80A, respectively. Elast-Eon also had significantly lower clot area of 5.2 cm2compared to 6.7, 6.1, and 6.9 cm2for PVC/DOS, SP-60D-60, and SG80A, respectively. Based on the results obtained for the base polymer comparison study, DBHD/N2O2-doped E2As was evaluated in short-term (4 h) rabbit studies to observe the NO effects on prevention of clotting and preservation of platelet function. Platelet preservation for this optimal NO release formulation was 97% of baseline after 4 h, and clot area was 0.9 cm2compared to 5.2 cm2for controls, demonstrating that combining E2As with NO release provides a truly advanced hemocompatible polymer coating for extracorporeal circuits and potentially other blood contacting applications.
authors.affiliation: Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI USA.
authors.forename: Hitesh
authors.initials: H
authors.lastname: Handa
authors.affiliation: Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI USA.
authors.forename: Terry C
authors.initials: TC
authors.lastname: Major
authors.affiliation: Department of Chemistry, University of Michigan, Ann Arbor, MI USA.
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Brisbois
authors.affiliation: Department of Internal Medicine, University of Michigan, Ann Arbor, MI USA.
authors.forename: Kagya A
authors.initials: KA
authors.lastname: Amoako
authors.affiliation: Department of Chemistry, University of Michigan, Ann Arbor, MI USA.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Meyerhoff
authors.affiliation: Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI USA.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Bartlett
keywords: Diazeniumdiolate; Extracorporeal Circulation; Nitric Oxide; PLGA; Platelets