Modification of Si(100) surface by the grafting of poly(ethylene glycol) for reduction in protein adsorption and platelet adhesion

The modification of argon plasma-pretreated single-crystal Si(100) wafer su rfaces via the UV-induced graft polymerization of poly(ethylene glycol) met hacrylate (PEGMA) macromonomer (molecular weight similar to 340) for biomat erials applications was explored. The modified Si(100) surfaces were charac terized by X-ray photoelectron spectroscopy and atomic force microscopy. Su rface peroxide concentrations resulting from the argon plasma treatment and subsequent atmospheric exposure were determined by a coupling reaction wit h diphenylpicrylhydrazyl. The results suggested that a short plasma treatme nt time of 10 s and brief air exposure were sufficient for generating an op timum amount of peroxides and hydroperoxides for the subsequent W-induced g raft polymerization. The graft concentration of the PEGMA polymer increased with increasing PEGMA macromonomer concentration for the graft polymerizat ion and with increasing W graft polymerization time. The PEGMA graft-polyme rized silicon surface with a high poly(ethylene glycol) graft concentration was very effective in preventing protein adsorption and platelet adhesion. The grafted PEGMA polymer layer on the Si(100) surface exhibited fairly go od stability during storage in a buffer solution. (C) 2001 John Wiley & Son s, Inc.