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

Paper BI-FrM10
Low-Fouling Amine-Terminated Poly(ethylene Glycol) Thin Layers and Effect of Immobilization Conditions on Their Mechanical and Physicochemical Properties

Friday, November 17, 2006, 11:00 am, Room 2014

Session: Biomolecular Surface Characterization II
Presenter: Y. Martin, Université de Sherbrooke, Canada
Authors: Y. Martin, Université de Sherbrooke, Canada
P. Vermette, Université de Sherbrooke, Canada
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The physicochemical and mechanical properties of amine-terminated covalently-bound poly(ethylene glycol) (PEG) layers are dependent on fabrication methods. Particularly, the use of a theta solvent yields dense bound PEG layers with properties not well described by traditional models. The polymer concentration is also known to be important for the layer properties. In this study, NHS-PEG-tBoc molecules of molecular weight 3,400 were immobilized on plasma-generated primary amine-containing surfaces at different concentrations and using different solvents including theta solvents. Light diffraction techniques were used in an attempt to understand the influence of polymer aggregation kinetics in a theta solvent on the final properties of the fabricated PEG layers. The polymer layer properties were characterized using X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) in force mode, quartz crystal microbalance (QCM) and fluorescence microscopy. Results show that polymer concentration in solution is an important indicator of final layer properties, and that the use of a theta solvent induces complex aggregation phenomena in solution, dependant on PEG concentration, yielding layers with unique properties such as greatly variable low-fouling potential or water trapping attributes. The PEG layers fabricated through the process described in this article are also shown to be chemically reactive, paving the way for the immobilization of bio-active molecules.