Fibrinogen adsorption and platelet lysis characterization of fluorinated surface-modified polyetherurethanes

Authors

  • T.M. Massa,

    1. Department of Chemical Engineering and Applied Science, University of Toronto, Ontario, Canada
    2. Institute of Biomaterials and Biomedical Engineering, University of Toronto, Ontario, Canada
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  • W.G. McClung,

    1. Department of Chemical Engineering and Pathology, McMaster University, Hamilton, Ontario, Canada
    2. Department of Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
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  • M.L. Yang,

    1. Department of Biomaterials, Faculty of Dentistry, University of Toronto, Ontario, Canada
    2. Interface Biologics, Toronto, Ontario, Canada
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  • J.Y.C. Ho,

    1. Interface Biologics, Toronto, Ontario, Canada
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  • J.L. Brash,

    1. Department of Chemical Engineering and Pathology, McMaster University, Hamilton, Ontario, Canada
    2. Department of Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
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  • J.P. Santerre

    Corresponding author
    1. Department of Chemical Engineering and Applied Science, University of Toronto, Ontario, Canada
    2. Institute of Biomaterials and Biomedical Engineering, University of Toronto, Ontario, Canada
    3. Department of Biomaterials, Faculty of Dentistry, University of Toronto, Ontario, Canada
    • Department of Chemical Engineering and Applied Science, University of Toronto, Ontario, Canada
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Abstract

A polyetherurethane (PU) was modified using fluorinated surface-modifying macromolecules (SMMs). A double radiolabel method was used simultaneously to measure the number of adhered platelets (51Cr) and the quantity of adsorbed Fg (125I), in a cone-and-plate instrument. The objectives were to determine if adsorbed Fg levels correlated to platelet adhesion on the surfaces, and to assess if any reductions in platelet adhesion for the SMM-treated surfaces resulted from surface-induced platelet lysis, rather than changes directly related to lower platelet activation and attachment on the novel surfaces. Platelet lysis was determined from lactate dehydrogenase (LDH) and unbound 51Cr released into plasma isolated from whole blood exposed to test materials. The corresponding Fg adsorption, evaluated under the same platelet adhesion conditions, did not account for the reduced platelet adhesion on the treated surfaces. LDH and 51Cr platelet release were very low and indicated no statistically significant differences between the materials. It was therefore concluded that platelet lysis did not contribute to the reduction in platelet adhesion characteristic observed on the SMM-treated surfaces. More importantly, the work emphasizes that the platelet activation cannot be inferred to by assessing the quantity of fibrinogen as is commonly done in the literature. The finding suggests a much more complex mechanism of action for the SMM surface modifiers. On-going work is investigating other Fg parameters such as protein binding affinity and protein conformational state in order to establish the mechanism by which the fluorinated surface modifiers may be reducing platelet adhesion via intermediary changes in initial protein adsorption. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res 2007

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