title: Application of quartz crystal microbalance to study the impact of pH and ionic strength on protein-silicone oil interactions.
abstract: In this study, we have used quartz crystal microbalance (QCM) to quantitate the adsorption of a protein on silicone oil coated surfaces as a function of protein concentration, pH and ionic strength using a 5 MHz quartz crystal. Protein adsorption isotherms were generated at different solution pH and ionic strengths. Surface saturation concentrations were selected from adsorption isotherms and used to generate adsorption profiles from pH 3.0 to 9.0, and at ionic strengths of 10 mM and 150 mM. At low ionic strength (10mM) and pH 5.0 (close to the isoelectric point of the protein), maximum adsorption of protein to the silicone oil surface was observed. At higher ionic strength (150 mM), no significant pH influence on adsorption was observed. QCM could be used as a reliable technique to study the binding of proteins to silicone oil coated surfaces.
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, University of Connecticut, 69N Eagleville Road, Unit 3092, Storrs, CT 06269, USA.
authors.forename: Nitin
authors.initials: N
authors.lastname: Dixit
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Maloney
authors.forename: Devendra S
authors.initials: DS
authors.lastname: Kalonia
mesh_terms: D000327:Adsorption; D004349:Drug Packaging; D005079:Excipients / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007141:Immunoglobulin Fc Fragments / Q000737:chemistry / Q000235:genetics; D007267:Injections; D007526:Isoelectric Point; D007700:Kinetics; D054327:Lubricants / Q000737:chemistry*; D009994:Osmolar Concentration; D011506:Proteins / Q000008:administration & dosage / Q000737:chemistry*; D058525:Quartz Crystal Microbalance Techniques; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D012827:Silicone Oils / Q000737:chemistry*; D055672:Static Electricity; D013499:Surface Properties; D013678:Technology, Pharmaceutical
chemical_list: D005079:Excipients; D007141:Immunoglobulin Fc Fragments; D054327:Lubricants; D011506:Proteins; D011993:Recombinant Fusion Proteins; D012827:Silicone Oils