title: Blood compatibility assessment of polymers used in drug eluting stent coatings.
abstract: Differences in thrombosis rates have been observed clinically between different drug eluting stents. Such differences have been attributed to numerous factors, including stent design, injury created by the catheter delivery system, coating application technologies, and the degree of thrombogenicity of the polymer. The relative contributions of these factors are generally unknown. This work focuses on understanding the thrombogenicity of the polymer by examining mechanistic interactions with proteins, human platelets, and human monocytes of a number of polymers used in drug eluting stent coatings, in vitro. The importance for blood interactions of adsorbed albumin and the retention of albumin was suggested by the data. Microscopic imaging and immunostaining enhanced the interpretation of results from the lactate dehydrogenase cell counting assay and provided insight into platelet interactions, total quantification, and morphometry. In particular, highly spread platelets may be surface-passivating, possibly inhibiting ongoing thrombotic events. In many of the assays used here, poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) showed a differentiated protein deposition pattern that may contribute to the explanation of the consistently thromboresistant blood-materials interaction for fluororpolymers cited in literature. These results are supportive of one of several possible factors contributing to the good thromboresistant clinical safety performance of PVDF-HFP coated drug eluting stents.
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, Washington 98195.
authors.forename: Luisa Mayorga
authors.initials: LM
authors.lastname: Szott
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, Washington 98195.
authors.forename: Colleen A
authors.initials: CA
authors.lastname: Irvin
authors.affiliation: Abbott Vascular, Innovation Incubator, Santa Clara, California 95052.
authors.forename: Mikael
authors.initials: M
authors.lastname: Trollsas
authors.affiliation: Abbott Vascular, Innovation Incubator, Santa Clara, California 95052.
authors.forename: Syed
authors.initials: S
authors.lastname: Hossainy
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, Washington 98195 and Department of Chemical Engineering, University of Washington, Seattle, Washington 98195.
authors.forename: Buddy D
authors.initials: BD
authors.lastname: Ratner
mesh_terms: D020099:Coated Materials, Biocompatible; D054855:Drug-Eluting Stents; D006801:Humans; D008422:Materials Testing; D015539:Platelet Activation
chemical_list: D020099:Coated Materials, Biocompatible