It is known that grafted polymer chains have a strong effect on the interaction of surfaces with blood and biological fluids. Our approach to developing biocompatible surfaces is to synthesize relatively large, surfactant-free solid polymer latex beads based on polystyrene and provide them with a reactive copolymer shell to allow grafting of acrylate-based monomers and co-monomers. These provide model, polymer-bearing surfaces which are then evaluated via biocompatibility reactions with proteins and cells. By assaying the number of reacted surface groups and the amount of monomer incorporated the molecular weights of the grafts are determined. The surfaces are then characterized by traditional (NMR), surface chemical (XPS) and non-traditional approaches (particle electrophoresis; contact angles in phase separated aqueous two phase mixtures) to provide unique descriptions of the grafted chain phase and its effects on biocompatibility. The grafted beads are further evaluated as high resolution chromatographic media by packing them in HPLC columns and measuring plate heights and partit ion coefficients for biomolecules, the latter parameter providing a further characterization of the grafted layer.
