IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Biomaterials Thursday Sessions
       Session BI-ThM

Paper BI-ThM6
Reversible Adsorption/Desorption of Proteins from a Thermally Switching Polymer Monolayer

Thursday, November 1, 2001, 10:00 am, Room 102

Session: Protein Surface Interaction
Presenter: D.L. Huber, Sandia National Laboratories
Authors: D.L. Huber, Sandia National Laboratories
M.A. Samara, Sandia National Laboratories
B.C. Bunker, Sandia National Laboratories
R.A. Manginell, Sandia National Laboratories
C.M. Matzke, Sandia National Laboratories
G. Dulleck, Sandia National Laboratories
Correspondent: Click to Email
The phase transitions of poly(N-isopropyl acrylamide) (poly NIPAM) hydrogels have been studied extensively for a number of years. We have investigated the thermal transitions of the linear polymer bound to silicon oxide surfaces. The poly NIPAM monolayers are grown from a self assembled monolayer of free radical initiators, and their properties towards protein adsorption are studied as a function of temperature using IR and UV-visible spectroscopies, as well as ellipsometry and fluorescence microscopy. At room temperature, the monolayers are swollen with water and are extremely resistant to protein adhesion, but at elevated temperatures ( above 35C) the polymer collapses and expels a large portion of the water. The collapsed polymer monolayers are capable of quickly adsorbing a protein monolayer. The layer of adsorbed protein can be completely desorbed by cooling the polymer to below its transition temperature. A well prepared monolayer has been shown to be capable of repeated adsorption and desorption cycles with no degradation of the effect. Poly NIPAM monolayers have been grown onto a microchip based platform containing micron scale resistive heaters capable of precisely controlling the surface temperature, and the adsorption and desorption of fluorescently labelled proteins monitored using flurorescence microscopy. Possible applications of on chip structures, as well as the adsorption/desorption kinetics will be discussed.