Adsorption of glycated proteins by boronic copolymer-coated adsorbents

The presence of glycated proteins in the plasma of diabetic patients may play a role in serious complications such as nephritis, retinosis, and nerve disorders. We evaluated the adsorption properties of copolymers of styreneboronic acid and styrenesulfonic acid for glycated protein and glycated lipoprotein. Porous glass with pore sizes of 50 and 100nm and cellulose gel were coated with or bound to the copolymer of styreneboronic acid, styrenesulfonic acid, and glycidyl methacrylate. These adsorbents showed selective adsorptivity for glycated albumin and glycated lipoprotein, depending on their boronic acid content. Copolymer composition affects the adsorption properties in a different manner for glycated albumin and glycated lipoprotein, suggesting that not only boronic acid but also sulfonic acid moieties play an important role in adsorption. The copolymer of styreneboronic acid and hydroxyethyl methacrylate had a smaller adsorption capacity than the copolymer of styreneboronic acid and styrenesulfonic acid without positive participation of the hydroxyethyl methacrylate moiety, which also showed the need for sulfonic acid in selective adsorption. Furthermore, these adsorbents had less capacity to activate the intrinsic blood coagulation cascade. Therefore, it may be possible to use these adsorbents to prevent the complications of diabetes by plasmapheresis.