Protein adsorption onto zirconia modified with terminally grafted polyvinylpyrrolidone

The potential effectiveness of poly(vinyl pyrrolidone) (PVP) as a zirconia surface modifier for protein adsorption reduction was investigated using ly sozyme (LYS). The relatively small size of LYS (45 x 30 x 30 Angstrom) allo wed for testing the adequacy of the graft polymerization method for produci ng a dense surface chain coverage to exclude LYS from direct interaction wi th the zirconia surface. The study demonstrated that a PVP brush layer is c apable of reducing lysozyme adsorption. Overall, the maximum adsorption cap acity decreased (by up to about 76%) due to surface modification with incre asing polymer/silane surface coverage ratio (mol/mol). Adsorption reduction , due to protein exclusion from the surface by the tethered polymer layer, increased significantly when the distance between surface chains was less t han the large axis of LYS (i.e., 45 Angstrom). The present results are enco uraging and suggest further consideration of polymer-modified ceramic surfa ces for reducing fouling of ceramic membranes during protein ultrafiltratio n and producing ceramic biocompatible surfaces for biomedical applications, (C) 2001 Academic Press.