AVS 46th International Symposium
    Surface Science Division Thursday Sessions
       Session SS1+AS+BI-ThM

Paper SS1+AS+BI-ThM7
Protein Adsorption to Model Surfaces: Probe Adhesion Between Fibrinogen and Patterned SAMs

Thursday, October 28, 1999, 10:20 am, Room 606

Session: Self-Assembled Monolayers
Presenter: L.F. Pardo, Clemson University
Authors: L.F. Pardo, Clemson University
T.B. Boland, Clemson University
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Interactions between blood and an artificial surface induce a rapid, thrombogenic response believed to be mediated by protein adsorption. In this study, atomic force microscopy (AFM) was used to measure directly non-specific forces between proteins and functionalized surfaces. A protein-modified AFM cantilever tip was used to probe of interactions between a model substrate and a single protein. Model surfaces consisted of both simple and microcontact-printed, -OH, -COOH, and -CH3 terminated self-assembled monolayers (SAMs) of alkanethiols on gold. Fibrinogen was used as the model protein due to its significance in biomaterial-mediated inflammatory responses. It was tethered to the probe tip using a synthetic polypeptide (polyserine). Various approaches were taken to link polyserine to a self-assembled monolayer on a gold substrate. Ellipsometric and vibrational spectroscopic measurements indicated that successive carbodiimide activation of a carboxyl-terminated alkanethiol and polyserine allowed for the successful formation of a polyserine-tethered fibrinogen film. The SAMs, polyserine and fibrinogen films were characterized by ellipsometry and contact angle measurements. Both AFM images and measurements will be presented and discussed. An understanding of how fibrinogen interacts under model conditions will give insight into more complicated real systems.