Selective protein adsorption modulates platelet adhesion and activation to oligo(ethylene glycol)-terminated self-assembled monolayers with C18 ligands

• Type: Article in International Scientific Journal
• Date: 2009

Authors

Ines C Goncalves (Author) Other; Cristina C L Martins (Author) Other; Mario A Barbosa (Author) FEUP; Esmaeel Naeemi (Author) Other; Buddy D Ratner (Author) Other

Journal

Title: Journal of Biomedical Materials Research - Part A

Vol. 89A No. 3

Pages: 642-653

ISSN: 1549-3296

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 17 Citations

ISI Web of Science

Scopus - 18 Citations

Scientific classification

FOS: Engineering and technology > Environmental biotechnology

CORDIS: Technological sciences > Engineering > Biomaterial engineering

Other information

Authenticus ID: P-003-JNM

DOI: 10.1002/jbm.a.32011

Abstract (EN): This study focuses on the selective binding of albumin to a nanostructured surfaces to inhibit other blood proteins from adsorbing thereby reducing platelet adhesion and activation. Tetra (ethylene-glycol)-terminated self-assembled monolayers (EG4 SAMs) with different percentages of C18 ligands on the Surface were characterized by contact angle measurements, X-ray photoelectron microscopy, infrared reflection-absorption spectroscopy, and ellipsometry. A specific surface (2.5% C18 SAM) was found to be selective for human serum albumin (HSA) in the presence of both albumin and fibrinogen (HFG). The importance of this concentration of C18 ligands was stressed in reversibility studies since that Surface exchanged almost all the preadsorbed HSA by HSA in solution, but not by HFG. The effect of protein adsorption in the subsequent adhesion and activation of platelets was studied by pre-immersing the surfaces in albumin and plasma before contact with platelets. Scanning electron microscopy and glutaraldehyde induced fluorescence technique images showed that as surfaces got more hydrophobic due to the immobilization of C18 ligands, the number of adherent platelets increased and their morphology changed from round to fully spread. Pre-immersion in HSA led to an 80% decrease in platelet adhesion and reduction of activation. Pre-immersion in 1% plasma was only relevant in 2.5% C18 SAMs since this was the only surface that demonstrated less adhesion of platelets comparing with buffer pre-immersion. However, they still adsorb more platelets then when HSA was preadsorbed. This was confirmed in competition studies between HSA and plasma that suggested that other plasma proteins were also adsorbing to this surface. (C) 2008 Wiley Periodicals, Inc. J Biomed Mater Res 89A: 642-653, 2009

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12