PROTEIN IMMOBILIZATION TO POLYSTYRENE VIA LONG POLY(ETHYLENE GLYCOL) CHAINS

Human albumin has been attached to 24-hole polystyrene plates via branched poly(ethylene glycol) (PEG) spacer arms. A tetraepoxide of PEG of molecular weight (1.4-1.5) x 10(4) g/mol was reacted with the protein in solution allowing approximately one-third of the oxirane rings to react. The protein conjugate was then coupled to the long, cationic polymer poly(ethylene imine) (PEl), and the protein-PEG-PEl adduct was subsequently adsorbed to preoxidized polystyrene. The amount of albumin bound was almost as high as the amount obtained by simple adsorption to unmodified polystyrene. Since the protein is linked to the surface via long, hydrophilic and noncharged chains, interactions between the biomolecule and the surface is minimized.