The effect of immobilization of thrombin inhibitors onto self-assembled monolayers on the adsorption and activity of thrombin

• Type: Article in International Scientific Journal
• Date: 2010

Authors

Freitas, SC (Author) Other; Mário Adolfo Barbosa (Author) FEUP; Martins, MCL (Author) Other

Journal

Title: Biomaterials

Vol. 31

Pages: 3772-3780

ISSN: 0142-9612

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 16 Citations

Scopus - 17 Citations

Other information

Authenticus ID: P-003-6W0

DOI: 10.1016/j.biomaterials.2010.01.097

Abstract (EN): 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-SAM5 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9