title: Thermally cross-linked PNVP films as antifouling coatings for biomedical applications.
abstract: Protein repellent coatings are widely applied to biomedical devices in order to reduce the nonspecific adhesion of plasma proteins, which can lead to failure of the device. Poly(N-vinylpyrrolidone) (PNVP) is a neutral, hydrophilic polymer with outstanding antifouling properties often used in these applications. In this paper, we characterize for the first time a cross-linking mechanism that spontaneously occurs in PNVP films upon thermal annealing. The degree of cross-linking of PNVP films and their solubility in water can be tailored by controlling the annealing, with no need for additional chemical treatment or irradiation. The physicochemical properties of the cross-linked films were investigated by X-ray photoelectron spectroscopy, infrared spectroscopy, neutron and X-ray reflectometry, ellipsometry, and atomic force microscopy, and a mechanism for the thermally induced cross-linking based on radical formation was proposed. The treated films are insoluble in water and robust upon immersion in harsh acid environment, and maintain the excellent protein-repellent properties of unmodified PNVP, as demonstrated by testing fibrinogen and immunoglobulin G adsorption with a quartz crystal microbalance. Thermal cross-linking of PNVP films could be exploited in a wide range of biotechnological applications to give antifouling properties to objects of any size, essentially making this an alternative to high-tech surface modification techniques.
authors.affiliation: School of Chemistry, Building F11, The University of Sydney, New South Wales 2006, Australia.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Telford
authors.forename: Michael
authors.initials: M
authors.lastname: James
authors.forename: Laurence
authors.initials: L
authors.lastname: Meagher
authors.forename: Chiara
authors.initials: C
authors.lastname: Neto
mesh_terms: D000327:Adsorption; D001798:Blood Proteins / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D006358:Hot Temperature; D008567:Membranes, Artificial; D018625:Microscopy, Atomic Force; D009502:Neutrons; D056951:Photoelectron Spectroscopy; D011145:Polyvinyls / Q000737:chemistry*; D011759:Pyrrolidines / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
chemical_list: D001798:Blood Proteins; D020099:Coated Materials, Biocompatible; D003432:Cross-Linking Reagents; D008567:Membranes, Artificial; D011145:Polyvinyls; D011759:Pyrrolidines; C505150:poly(N-vinylpyrrolidine)