AVS 53rd International Symposium
    Biomaterial Interfaces Friday Sessions
       Session BI-FrM

Paper BI-FrM7
Fibronectin Adsorption onto Tantalum-Oxide Examined by QCM-D and Elipsometry: The Influence of Nano-Roughness

Friday, November 17, 2006, 10:00 am, Room 2014

Session: Biomolecular Surface Characterization II
Presenter: M.B. Hovgaard, University of Aarhus, Denmark
Authors: M.B. Hovgaard, University of Aarhus, Denmark
K. Rechendorff, University of Aarhus, Denmark
F. Besenbacher, University of Aarhus, Denmark
M. Foss, University of Aarhus, Denmark
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The adsorption of fibronectin onto tantalum-oxide is investigated probing the effects of a nano-rough, stochastic morphology on the structure and functionality of an adsorbed protein layer. Nano-rough substrates were produced by e-gun evaporation of tantalum onto standard QCM-D substrates at oblique incidence deposition, allowing the production of self-affine surfaces@footnote 1@ with ~ 4 nm RMS roughness as characterized by AFM. A comparative study of the protein adsorption onto flat versus nano-rough substrates was conducted using Ellipsometry and QCM-D. A characterization of the adsorbed layers was facilitated by variation of the protein concentration and monitoring of the specific versus non-specific antibody adsorption along with utilizing the different sensitivity of the two techniques.This including a direct comparison between the dry(Ellipsometry) and hydrated(QCM-D) surface densities further extended by the viscoelastic properties(QCM-D) of the adsorbed layers. Results show a significant influence of the nano-roughness on saturation coverage and the viscoelastic properties of the resulting protein layer. Compared to the flat morphology, the saturated protein films on the rough substrates show higher surface densities (area-effect) and non-trivial effects such as a more rigid packing (lower QCM-D dissipation) and decreased specific antibody adsorption, both indicating a changed protein configuration. @FootnoteText@ @footnote 1@ K. Rechendorff, M.B.Hovgaard, M.Foss, F.Besenbacher Appl. Phys. Lett. 87, 073105 (2005).