Competitive plasma protein adsorption onto fluorinated polyimide surfaces

A series of fluorinated polyimides cured at different temperatures was prepared, and plasma protein adsorption and platelet adhesion onto the polyimide films were evaluated in vitro using scanning electron microscopy, a micro-bicinchoninic acid protein assay, and a gold-colloid-labeled immunoassay. In particular, we focused on competitive plasma protein adsorption onto polyimide film because elucidation of the competitive adsorption mechanism is needed for a good understanding of in vivo biocompatibility of polyimide. Interestingly, the trend of IgG adsorption onto the polyimide surface measured in human plasma was completely contrary to that observed with IgG dissolved in PBS, and the adsorption increased with an increase in the curing temperature. We propose that the human plasma F(c) region in IgG might selectively adsorb onto polyimide film cured at high temperatures because of competitive plasma protein adsorption to the surface.