Minimization of protein adsorption on poly(vinylidene fluoride)

Surfaces covered with polyethylene glycol (PEG) have been shown to be biocompatible because PEG yields nonimmunogenicity, nonantigenicity and protein rejection. To produce a biocompatible surface coating, we have developed a method for grafting PEG onto modified poly(vinylidene fluoride) (PVDF) films. The first step was to create carboxy groups on the PVDF surface following covalente coupling of polyethylenimine (PEI) to achieve high density of amino groups. These surface amines were reacted with formyl-terminated PEG's with various molecular weight. The modified PVDF surface was characterized by means of static contact angle measurements, infrared (IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The influence of the chain length on lysozyme repellence was investigated by means of surface-MALDI-Tof mass spectrometry (Surface-MALDI-Tof-MS). Lysozyme adsorption was significantly suppressed on the PEG 5000 modified PVDF surface.