



@article {3285,
	title = {Selective albumin-binding surfaces modified with a thrombin-inhibiting peptide},
	journal = {Acta Biomaterialia},
	volume = {10},
	year = {2014},
	note = {Export Date: 21 November 2014},
	month = {2014},
	pages = {1227 - 1237},
	abstract = {Blood-contacting medical devices have been associated with severe clinical complications, such as thrombus formation, triggered by the activation of the coagulation cascade due to the adsorption of certain plasma proteins on the surface of biomaterials. Hence, the coating of such surfaces with antithrombotic agents has been used to increase biomaterial haemocompatibility. Biomaterial-induced clotting may also be decreased by albumin adsorption from blood plasma in a selective and reversible way, since this protein is not involved in the coagulation cascade. In this context, this paper reports that the immobilization of the thrombin inhibitor D-Phe-Pro-D-Arg-D-Thr-CONH 2 (fPrt) onto nanostructured surfaces induces selective and reversible adsorption of albumin, delaying the clotting time when compared to peptide-free surfaces. fPrt, synthesized with two glycine residues attached to the N-terminus (GGfPrt), was covalently immobilized onto self-assembled monolayers (SAMs) having different ratios of carboxylate-hexa(ethylene glycol)- and tri(ethylene glycol)-terminated thiols (EG6-COOH/EG3) that were specifically designed to control GGfPrt orientation, exposure and density at the molecular level. In solution, GGfPrt was able to inactivate the enzymatic activity of thrombin and to delay plasma clotting time in a concentration-dependent way. After surface immobilization, and independently of its concentration, GGfPrt lost its selectivity to thrombin and its capacity to inhibit thrombin enzymatic activity against the chromogenic substrate n-p-tosyl-Gly-Pro-Arg-p-nitroanilide. Nevertheless, surfaces with low concentrations of GGfPrt could delay the capacity of adsorbed thrombin to cleave fibrinogen. In contrast, GGfPrt immobilized in high concentrations was found to induce the procoagulant activity of the adsorbed thrombin. However, all surfaces containing GGfPrt have a plasma clotting time similar to the negative control (empty polystyrene wells), showing resistance to coagulation, which is explained by its capacity to adsorb albumin in a selective and reversible way. This work opens new perspectives to the improvement of the haemocompatibility of blood-contacting medical devices. {\textcopyright} 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.},
	keywords = {Albumin, Blood compatibility, Clotting, Surface modification, Thrombin},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84895067841\&partnerID=40\&md5=8486186625f8f4f1cbc538bb3e34dd82},
	author = {Freitas, S.C. and Maia, S. and Figueiredo, A.C. and Gomes, P. and Pereira, P.J.B. and Barbosa, M.A. and Martins, M.C.L.}
}
@booklet {2190,
	title = {Bioengineered surfaces to improve the blood compatibility of biomaterials through direct thrombin inactivation},
	howpublished = {Acta BiomaterialiaActa Biomater.},
	year = {2012},
	note = {Export Date: 21 November 2012Source: ScopusArticle in Pressdoi: 10.1016/j.actbio.2012.07.020Language of Original Document: EnglishCorrespondence Address: Martins, M.C.L.; INEB - Instituto de Engenharia Biom{\'e}dica, Universidade do Porto, Rua do Campo Alegre 823, 415email: cmartins@ineb.up.pt},
	month = {2012///},
	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{\textquoteright}s potential to improve the hemocompatibility of biomaterials used in the production of blood-contacting devices. {\textcopyright} 2012 Acta Materialia Inc.
},
	keywords = {Coagulation, Hemocompatibility, Protein adsorption, Surface functionalization, Thrombin},
	isbn = {17427061 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84865246462\&partnerID=40\&md5=278b2e7d1427a6032eba9ecbd01c3872},
	author = {Freitas, S.C. and Cereija, T.B. and Figueiredo, A.C. and Os{\'o}rio, H. and Pereira, P.J.B. and Barbosa, M.A. and Martins, M.C.L.}
}
@article {2279,
	title = {The effect of immobilization of thrombin inhibitors onto self-assembled monolayers on the adsorption and activity of thrombin},
	journal = {BiomaterialsBiomaterials},
	volume = {31},
	year = {2010},
	note = {Cited By (since 1996): 7Export Date: 21 November 2012Source: ScopusCODEN: BIMADdoi: 10.1016/j.biomaterials.2010.01.097PubMed ID: 20153046Language of Original Document: EnglishCorrespondence Address: Martins, M.C.L.; INEB - Instituto de Engenharia Biom{\'e}dica, Divis{\~a}o de Biomateriais, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal; email: cmartins@ineb.up.ptChemicals/CAS: thrombin, 9002-04-4; Albumins; Gold, 7440-57-5; Immobilized Proteins; Iodine Radioisotopes; Peptides; Solutions; Thrombin, 3.4.21.5References: Gorbet, M.B., Sefton, M.V., Biomaterial-associated thrombosis: roles of coagulation factors, complement, platelets and leukocytes (2004) Biomaterials, 25 (26), pp. 5681-5703;Ratner, B.D., Hoffman, A.F., Schoen, F.J., Lemons, J.L., (2004) Biomaterials science - an introduction to materials in medicine. 2nd ed., , Elsevier Academic Press, San Diego, CA, USA; 
Bode, W., Structure and interaction modes of thrombin (2006) Blood Cells Mol Dis, 36 (2), pp. 122-130; 
Huntington, J.A., Molecular recognition mechanisms of thrombin (2005) J Thromb Haemost, 3 (8), pp. 1861-1872; 
Schwienhorst, A., Direct thrombin inhibitors - a survey of recent developments (2006) Cell Mol Life Sci, 63 (23), pp. 2773-2791; 
Tseng, P.-Y., Rele, S.S., Sun, X.-L., Chaikof, E.L., Membrane-mimetic films containing thrombomodulin and heparin inhibit tissue factor-induced thrombin generation in a flow model (2006) Biomaterials, 27 (12), pp. 2637-2650; 
Sperling, C., Salchert, K., Streller, U., Werner, C., Covalently immobilized thrombomodulin inhibits coagulation and complement activation of artificial surfaces in vitro (2004) Biomaterials, 25 (21), pp. 5101-5113; 
Lin, J.C., Tseng, S.M., Surface characterization and platelet adhesion studies on polyethylene surface with hirudin immobilization (2001) J Mater Sci Mater Med, 12 (9), pp. 827-832; 
Wendel, H.P., Ziemer, G., Coating-techniques to improve the hemocompatibility of artificial devices used for extracorporeal circulation (1999) Eur J Cardiothorac Surg, 16 (3), pp. 342-350; 
Werner, C., Maitz, M.F., Sperling, C., Current strategies towards hemocompatible coatings (2007) J Mater Chem, 17 (32), pp. 3376-3384; 
Weitz, J.I., Crowther, M., Direct thrombin inhibitors (2002) Thromb Res, 106 (3), pp. V275-V284; 
Di Nisio, M., Middeldorp, S., B{\"u}ller, H.R., Direct thrombin inhibitors (2005) N Engl J Med, 353 (10), pp. 1028-1040; 
Stone, S.R., Hofsteenge, J., Kinetics of the inhibition of thrombin by hirudin (1986) Biochemistry, 25 (16), pp. 4622-4628; 
Grutter, M.G., Priestle, J., Rahuel, J., Grossenbacher, H., Bode, W., Hofsteenge, J., Crystal structure of the thrombin-hirudin complex: a novel mode of serine protease inhibition (1990) EMBO J, 9 (8), pp. 2361-2365; 
Lahann, J., Pl{\"u}ster, W., Klee, D., Gattner, H.G., H{\"o}cker, H., Immobilization of the thrombin inhibitor r-hirudin conserving its biological activity (2001) J Mater Sci Mater Med, 12 (9), pp. 807-810; 
Phaneuf, M.D., Berceli, S.A., Bide, M.J., Quist, W.C., LoGerfo, F.W., Covalent linkage of recombinant hirudin to poly(ethylene terephthalate) (Dacron): creation of a novel antithrombin surface (1997) Biomaterials, 18 (10), pp. 755-765; 
Wyers, M.C., Phaneuf, M.D., Rzucidlo, E.M., Contreras, M.A., Logerfo, F.W., Quist, W.C., In~vivo assessment of a novel Dacron surface with covalently bound recombinant hirudin (1999) Cardiovasc Pathol, 8 (3), pp. 153-159; 
Maraganore, J.M., Bourdon, P., Jablonski, J., Ramachandran, K.L., Fenton Ii, J.W., Design and characterization of hirulogs: a novel class of bivalent peptide inhibitors of thrombin (1990) Biochemistry, 29 (30), pp. 7095-7101; 
Maraganore, J.M., Chao, B., Joseph, M.L., Jablonski, J., Ramachandran, K.L., Anticoagulant activity of synthetic hirudin peptides (1989) J Biol Chem, 264 (15), pp. 8692-8698; 
Sun, X., Sheardown, H., Tengvall, P., Brash, J.L., Peptide modified gold-coated polyurethanes as thrombin scavenging surfaces (2000) J Biomed Mater Res, 49 (1), pp. 66-78; 
Bain, C.D., Troughton, E.B., Tao, Y.T., Evall, J., Whitesides, G.M., Nuzzo, R.G., Formation of monolayer films by the spontaneous assembly of organic thiols from solution onto gold (1989) J Am Chem Soc, 111 (1), pp. 321-335; 
Herrwerth, S., Eck, W., Reinhardt, S., Grunze, M., Factors that determine the protein resistance of oligoether self-assembled monolayers - internal hydrophilicity, terminal hydrophilicity, and lateral packing density (2003) J Am Chem Soc, 125 (31), pp. 9359-9366; 
Lottenberg, R., Christensen, U., Jackson, C.M., Coleman, P.L., Assay of coagulation proteases using peptide chromogenic and fluorogenic substrates (1981) Meth Enzymol, 80 (PART C), pp. 341-361; 
Martins, M.C.L., Ratner, B.D., Barbosa, M.A., Protein adsorption on mixtures of hydroxyl- and methyl-terminated alkanethiols self-assembled monolayers (2003) J~Biomed Mater Res A, 67 A (1), pp. 158-171; 
Martins, M.C.L., Curtin, S.A., Freitas, S.C., Salgueiro, P., Ratner, B.D., Barbosa, M.A., Molecularly designed surfaces for blood deheparinization using an immobilized heparin-binding peptide (2009) J Biomed Mater Res A, 88 (1), pp. 162-173; 
(1993) Iodine-125. A guide to radioiodination techniques, , Amersham Life Science, Little Chalfort; 
Rahmelow, K., Hubner, W., Ackermann, T., Infrared absorbances of protein side chains (1998) Anal Biochem, 257 (1), pp. 1-11; 
Barth, A., The infrared absorption of amino acid side chains (2000) Prog Biophys Mol Biol, 74 (3-5), pp. 141-173; 
Li, L., Chen, S., Zheng, J., Ratner, B.D., Jiang, S., Protein adsorption on oligo(ethylene glycol)-terminated alkanethiolate self-assembled monolayers: the molecular basis for nonfouling behavior (2005) J Phys Chem B, 109 (7), pp. 2934-2941; 
Beamson, G., Briggs, D., (1992) High resolution XPS of organic polymers, , John Wiley and Sons, Ltd;, New York; 
Adden, N., Gamble, L.J., Castner, D.G., Hoffmann, A., Gross, G., Menzel, H., Phosphonic acid monolayers for binding of bioactive molecules to titanium surfaces (2006) Langmuir, 22 (19), pp. 8197-8204; 
Sousa, S.R., Moradas-Ferreira, P., Saramago, B., Viseu Melo, L., Barbosa, M.A., Human serum albumin adsorption on TiO 2 from single protein solutions and from plasma (2004) Langmuir, 20 (22), pp. 9745-9754; 
Di Cera, E., Thrombin interactions (2003) Chest, 124 (SUPPL. 3), pp. 11S-17S; 
Markwardt, F., Historical perspective of the development of thrombin inhibitors (2002) Pathophysiol Haemost Thromb, 32 (SUPPL. 3), pp. 15-22; 
Hearn, M.T., 1,1'-Carbonyldiimidazole-mediated immobilization of enzymes and affinity ligands (1987) Methods Enzymol, 135, pp. 102-117; 
St{\"o}llner, D., Scheller, F.W., Warsinke, A., Activation of cellulose membranes with 1,1'-carbonyldiimidazole or 1-cyano-4-dimethylaminopyridinium tetrafluoroborate as a basis for the development of immunosensors (2002) Anal Biochem, 304 (2), pp. 157-165; 
Martins, M.C.L., Naeemi, E., Ratner, B.D., Barbosa, M.A., Albumin adsorption on Cibacron Blue F3G-A immobilized onto oligo(ethylene glycol)- terminated self-assembled monolayers (2003) J Mater Sci Mater Med, 14 (11), pp. 945-954; 
Dee, K.C., Puleo, D.A., Bizios, R., (2002) An introduction to tissue-biomaterial interactions, , Wiley-Liss, Inc; 
Malmsten, M., Lassen, B., Competitive adsorption at hydrophobic surfaces from binary protein systems (1994) J Colloid Interface Sci, 166 (2), pp. 490-498
},
	month = {2010///},
	pages = {3772 - 3780},
	abstract = {Thrombus formation is the major problem associated with biomaterials for blood contact medical devices. The immobilization of inhibitors to thrombin, a serine protease that plays a central role on the coagulation system, on the surface of biomaterials should be a good strategy to avoid blood clotting and increase their hemocompatibility. The aim of this work is the design of a nanostructured surface with capacity to adsorb and inactivate thrombin. The pentapeptide sequence d-Phenylalanine-Proline-Arginine-Proline-Glycine (fPRPG), that was described as a thrombin inhibitor, was immobilized onto tetra(ethylene glycol) terminated self-assembled monolayers (EG4-SAMs). Surface containing different amounts of fPRPG were prepared using different concentrations of N,N'-Carbonyldiimidazole (CDI) during immobilization. The efficiency of fPRPG immobilization was followed using ellipsometry, contact angle measurements, Infrared reflection absorption spectroscopy (IRRAS) and X-ray photoelectron spectroscopy (XPS). Thrombin adsorption was quantified using radiolabelled thrombin and its activity in solution and after adsorption on the developed surfaces was assessed using a chromogenic assay. It was found that, although the immobilization of fPRPG on to EG4-SAMs does not increase its selectivity to thrombin, the activity of the adsorbed thrombin was inhibited in a peptide concentration dependent way. We concluded that SAMs with fPRPG immobilized in high amounts can be used as thrombin-inhibitor surfaces, which is a good step on the development of new surfaces for blood contact devices. {\textcopyright} 2010 Elsevier Ltd. All rights reserved.},
	keywords = {Absorption spectroscopy, Adsorption, adsorption kinetics, Albumins, Amino Acid Sequence, Amino acids, Angle measurement, article, Biomaterials, Blood, Blood clotting, Blood contact, Carbonyldiimidazole, Coagulation, Coagulation system, concentration (parameters), Concentration-dependent, Contact angle, D-phenylalanine, ellipsometry, Ethylene, Ethylene Glycol, ethylene glycol derivative, gold, Hemocompatibility, Humans, imidazole derivative, Immobilized Proteins, Infrared reflection absorption spectroscopy, infrared spectroscopy, Iodine Radioisotopes, isotope labeling, Medical Devices, monolayer culture, nanoanalysis, Nanostructured surface, peptide, Peptide immobilization, Peptides, phenylalanylprolylarginylprolylglycine, Phosphatases, priority journal, Protein adsorption, protein assembly, protein function, protein immobilization, quantitative study, Sams, Self assembled monolayers, Self-assembled monolayers, Serine protease, Solubility, Solutions, Spectroscopy, Fourier Transform Infrared, Surface functionalization, Surface Properties, Tetra, tetra(ethylene glycol), Thrombin, thrombin inhibitor, Thrombin inhibitors, Thrombus formation, unclassified drug, X ray photoelectron spectroscopy},
	isbn = {01429612 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77649271932\&partnerID=40\&md5=f7180daf23d326319cf6d8dbf0eac77c},
	author = {Freitas, S.C. and Barbosa, M.A. and Martins, M.C.L.}
}
