| Title | Bioengineered surfaces to improve the blood compatibility of biomaterials through direct thrombin inactivation |
| Publication Type | Miscellaneous |
| Year of Publication | 2012 |
| Authors | Freitas, SC, Cereija, TB, Figueiredo, AC, Osório, H, Pereira, PJB, Barbosa, MA, Martins, MCL |
| ISBN Number | 17427061 (ISSN) |
| Keywords | Coagulation, Hemocompatibility, Protein adsorption, Surface functionalization, Thrombin |
| Abstract | Thrombus formation, due to thrombin generation, is a major problem affecting blood-contacting medical devices. This work aimed to develop a new strategy to improve the hemocompatibility of such devices by the immobilization of a naturally occurring thrombin inhibitor into a nanostructured surface. Boophilin, a direct thrombin inhibitor from the cattle tick Rhipicephalus microplus, was produced as a recombinant protein in Pichia pastoris. Boophilin was biotinylated and immobilized on biotin-terminated self-assembled monolayers (SAM) via neutravidin. In order to maintain its proteinase inhibitory capacity after surface immobilization, boophilin was biotinylated after the formation of a boophilin-thrombin complex to minimize the biotinylation of the residues involved in thrombin-boophilin interaction. The extent of boophilin biotinylation was determined using matrix-assisted laser desorption/ionization-time of flight/time of flight mass spectrometry. Boophilin immobilization and thrombin adsorption were quantified using quartz crystal microbalance with dissipation. Thrombin competitive adsorption from human serum was assessed using 125I-thrombin. Thrombin inhibition and plasma clotting time were determined using spectrophotometric techniques. Boophilin-coated SAM were able to promote thrombin adsorption in a selective way, inhibiting most of its activity and delaying plasma coagulation in comparison with boophilin-free surfaces, demonstrating boophilin's potential to improve the hemocompatibility of biomaterials used in the production of blood-contacting devices. © 2012 Acta Materialia Inc.
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| URL | http://www.scopus.com/inward/record.url?eid=2-s2.0-84865246462&partnerID=40&md5=278b2e7d1427a6032eba9ecbd01c3872 |
