Protein adsorption on 18-alkyl chains immobilized on hydroxyl-terminated self-assembled monolayers

Citation

Gonçalves, Inês Castro; Martins, Maria Cristina L.; Barbosa, Mário A.; & Ratner, Buddy D. (2005). Protein adsorption on 18-alkyl chains immobilized on hydroxyl-terminated self-assembled monolayers. Biomaterials, 26(18), 3891-3899.

Abstract

Surfaces of devices that contact blood accumulate adsorbed and denatured proteins perhaps triggering activation of the coagulation system. A renewable layer of albumin would biologically "passivate" the surface and prevent thrombus formation. Based on the approach of selectively binding albumin to fatty acids, different percentages of a compound with 18 carbons (C18) were immobilized on OH-terminated self-assembled monolayers (SAMs). Fourier transform infrared reflection absorption spectroscopy (IRAS), ellipsometry, contact angle (and surface free energy) and X-ray photoelectron spectroscopy (XPS) measurements were used to characterize these surfaces and proved that there is an efficient immobilization of C18. There is an increase of the thickness and hydrophobicity of SAMs with an increasing percentage of C18. Adsorption of human serum albumin (HSA) was evaluated using radiolabelled (125)I-HSA and IRAS. This study showed a gradual increase of HSA adsorption with the increase of surface hydrophobicity. Regarding competitive binding and exchangeability of albumin towards fibrinogen, it was proved, by radiolabelling, that SAMs prepared from solutions with 2.5% C18 presented considerable adsorption in a selective and reversible way.

Keyword(s)

Adsorption
Coated Materials, Biocompatible
Crystallization
Fibrinogen
Humans
Hydroxyl Radical
Materials Testing
Protein Binding
Serum Albumin
Sulfhydryl Compounds
Surface Properties

Reference Type

Journal Article

Secondary Title

Biomaterials

Author(s)

Gonçalves, Inês Castro
Martins, Maria Cristina L.
Barbosa, Mário A.
Ratner, Buddy D.

Year Published

2005

Volume Number

Issue Number

Pages

3891-3899