title: Protein binding properties of surface-modified porous polyethylene membranes.
abstract: In this study, we quantified the adsorption of immunoglobulin G (IgG) protein onto several polyelectrolyte-modified sintered porous polyethylene (PPE) membranes. The polymer surfaces had both cationic and anionic charges obtained via the adsorption of polyethylenimine (PEI) and polyacrylic acid (PAA), respectively, onto plasma-activated PPE. The amount of IgG adsorption was determined by measuring the gamma radiation emitted by [125I]-IgG radio labeled protein. By studying the impact of pH and ionic strength on IgG adsorption, we attempted to characterize the role and nature of the electrostatic interactions involved in the adsorption process to better understand how these interactions were influenced by the charge and structure of immobilized polyelectrolyte complexes at modified membrane surfaces. We were able to show that surface modification of PPE membranes with adsorbed PEI monolayers and PEI-PAA bilayers can greatly improve the IgG binding ability of the membrane under optimized conditions. We also showed that the observed improvement in the IgG binding is derived from electrostatic interactions between IgG and the polyelectrolyte surface. In addition, we found that the greatest IgG adsorption occurred when the IgG and the surface possessed predominantly opposite charges, rather than when the surface possessed the greatest electrostatic charge. Finally, we have found that the molecular weight of the terminating polyelectrolyte has a noticeable effect upon the electrostatic interactions between IgG and the PEI-PAA bilayer-modified PPE surfaces.
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
authors.forename: George
authors.initials: G
authors.lastname: Greene
authors.forename: Harish
authors.initials: H
authors.lastname: Radhakrishna
authors.forename: Rina
authors.initials: R
authors.lastname: Tannenbaum
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000327:Adsorption; D000838:Anions; D001672:Biocompatible Materials / Q000737:chemistry*; D002412:Cations; D004573:Electrolytes / Q000737:chemistry; D005720:Gamma Rays; D006863:Hydrogen-Ion Concentration; D007074:Immunoglobulin G / Q000737:chemistry; D007477:Ions; D008051:Lipid Bilayers; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008970:Molecular Weight; D020959:Polyethylene / Q000737:chemistry*; D011094:Polyethyleneimine / Q000737:chemistry; D011095:Polyethylenes; D011108:Polymers / Q000737:chemistry; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry*; D055672:Static Electricity; D013499:Surface Properties
chemical_list: D000180:Acrylic Resins; D000838:Anions; D001672:Biocompatible Materials; D002412:Cations; D004573:Electrolytes; D007074:Immunoglobulin G; D007477:Ions; D008051:Lipid Bilayers; D046911:Macromolecular Substances; D011095:Polyethylenes; D011108:Polymers; D011506:Proteins; C006903:carbopol 940; D020959:Polyethylene; D011094:Polyethyleneimine