AVS 45th International Symposium
    Biomaterial Interfaces Group Monday Sessions
       Session BI-MoM

Paper BI-MoM1
Effect of Surface Rheology on Anti-Adhesive Properties of Water-Soluble Thin Films

Monday, November 2, 1998, 8:20 am, Room 326

Session: Protein Solid-Surface Interactions
Presenter: J.W. Schneider, Naval Research Laboratory
Authors: J.W. Schneider, Naval Research Laboratory
W.R. Barger, Naval Research Laboratory
J.-B.D. Green, Naval Research Laboratory
R.F. Brady, Jr., Naval Research Laboratory
G.U. Lee, Naval Research Laboratory
Correspondent: Click to Email
Thin films of water-soluble polymers, including poly (ethylene oxide), have been used to improve the biofouling resistance and biocompatibility of surfaces. Their effectiveness has been traced to strong associations with water, leading to short-ranged, repulsive hydration forces, and to steric stabilization forces, which are related to the restriction of surface mobility as potential adherends approach them. With the rational molecular design of anti-bioadhesive coatings in mind, we work to decouple each of these effects by making sensitive nano-scale force measurements on organized monolayers hosting oligomers of controlled molecular weight and surface density. In this work, we employ the atomic force microscope (AFM) in two modes to obtain these two surface characteristics. Surface rheological properties, which are a measure of the propensity for steric stabilization, are obtained by driving the AFM tip across a frequency spectrum and measuring the phase and amplitude of the cantilever response as a function of probe/surface separation distance. Short-range forces are measured by operating the AFM in conventional static force modulation mode. AFM tips are functionalized to reflect pertinent biological chemistry using thiol SAM's terminated by carboxylic acids, amine groups, and the monosaccharide sialic acid.