title: Bioengineering of a novel small diameter polyurethane vascular graft with covalently bound recombinant hirudin.
abstract: Development of a small diameter prosthetic vascular graft with surface based antithrombin properties should aid in maintaining early graft patency in small vessel reconstruction. The purpose of this study was to bind covalently a basecoat protein (canine serum albumin [CSAJ) and a potent antithrombin agent (recombinant hirudin [rHir]) to 4 mm inner diameter poly(carbonate urea) urethane grafts with reactive carboxylic acid groups (cPU). 125I-CSA was covalently bound to 1 cm length segments of cPU grafts using the carbodimide cross-linker, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). To bind 125I-rHir covalently, CSA was modified with the heterobifunctional cross-linker sulfosuccinimidyl 4-(N-maleimidomethyl) cyclohexane-1-carboxylate (sulfo-SMCC) before linkage to the cPU surface with EDC (cPU-CSA-SMCC). 125I-rHir was modified with Traut's reagent and reacted with the cPU-CSA-SMCC surface, covalently linking 125I-rHir to surface bound CSA. 125I-CSA binding to the cPU graft surface (34,235 ng/segment) was ninefold, sevenfold, and 10-fold greater than controls with nonspecifically bound 125I-CSA. Covalent linkage of 125I-rHir to the cPU-CSA-SMCC surface (9,974 ng/segment) was 172, 192, and 142-fold greater than controls with nonspecifically bound 125I-rHir. Surface antithrombin properties were characterized using a chromogenic assay to measure residual thrombin activity. Evaluation of surface antithrombin activity showed significantly greater 131I-thrombin inhibition and binding by the cPU surface with covalently bound 125I-rHir, as compared with controls. Release of 125I-rHir from the cPU surface was minimal as compared with controls. Therefore, rHir can be covalently linked to a novel small diameter polyurethane vascular graft surface while maintaining its potent antithrombin properties.
authors.affiliation: Department of Surgery, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Phaneuf
authors.forename: D J
authors.initials: DJ
authors.lastname: Dempsey
authors.forename: M J
authors.initials: MJ
authors.lastname: Bide
authors.forename: M
authors.initials: M
authors.lastname: Szycher
authors.forename: W C
authors.initials: WC
authors.lastname: Quist
authors.forename: F W
authors.initials: FW
authors.lastname: LoGerfo
mesh_terms: D001807:Blood Vessel Prosthesis; D006629:Hirudins; D011140:Polyurethanes; D011474:Prosthesis Design; D011994:Recombinant Proteins; D013917:Thrombin
chemical_list: D006629:Hirudins; D011140:Polyurethanes; D011994:Recombinant Proteins; D013917:Thrombin