A Biologically Active Surface Enzyme Assembly that Attenuates Thrombus Formation
Activation of hemostatic pathways by blood‐contacting materials remains a major hurdle in the development of clinically durable artificial organs and implantable devices. Here, it is postulated that surface‐induced thrombosis may be attenuated by the reconstitution onto blood contacting surfaces of bioactive enzymes that regulate the production of thrombin, a central mediator of both coagulation and platelet activation cascades. Thrombomodulin (TM), a transmembrane protein expressed by endothelial cells, is an established negative regulator of thrombin generation in the circulatory system. Traditional techniques to covalently immobilize enzymes on solid supports may modify residues contained within or near the catalytic site, thus reducing the bioactivity of surface enzyme assemblies. In this report, a molecular engineering and bioorthogonal chemistry approach to site‐specifically immobilize a biologically active recombinant human TM fragment onto the luminal surface of small diameter prosthetic vascular grafts is presented. Bioactivity and biostability of TM modified grafts is confirmed in vitro and the capacity of modified grafts to reduce platelet activation is demonstrated using a non‐human primate model. These studies indicate that molecularly engineered interfaces that display TM actively limit surface‐induced thrombus formation.
Document Type: Research Article
Affiliations: 1: Departments of Biomedical Engineering and Surgery, Georgia Institute of Technology and Emory University, Atlanta, GA 30322, USA 2: Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, and the Wyss Institute of Biologically Inspired, Engineering of Harvard University, Boston, MA 02115, USA 3: Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97006, USA 4: Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
Publication date: 2011-12-20