Surface modification of polyaniline film by grafting of poly(ethylene glycol) for reduction in protein adsorption and platelet adhesion

Chemical modification of emeraldine (EM) base films via UV-induced surface graft copolymerization with methoxy-poly(ethylene glycol) monomethacrylate (PEGMA) macromonomer had been carried out in aqueous media. In all cases, the graft concentration of the PEGMA polymer on EM surface increased with increasing UV graft copolymerization time and PEGMA macromonomer concentration. The surface-modified EM films were characterized by contact angle, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) measurements. The pristine EM base film, the PEGMA-graft copolymerized EM film, and their respective protonated counterparts on protein adsorption and platelet adhesion were studied in detail. The protein adsorption and platelet adhesion on EM surfaces were studied by dye-interaction method and scanning electron microscopy (SEM), respectively. The EM film with a high concentration of surface-grafted poly(ethylene glycol) (PEG) was very effective in reducing protein adsorption and platelet adhesion. The effectiveness in reducing protein adsorption and platelet adhesion was further enhanced through doping or protonation of the EM and the PEG-modified EM films.