title: Zinc-decorated silica-coated magnetic nanoparticles for protein binding and controlled release.
abstract: The aim of this study was to be able to reversibly bind histidine-rich proteins to the surface of maghemite magnetic nanoparticles via coordinative bonding using Zn ions as the anchoring points. We showed that in order to adsorb Zn ions on the maghemite, the surface of the latter needs to be modified. As silica is known to strongly adsorb zinc ions, we chose to modify the maghemite nanoparticles with a nanometre-thick silica layer. This layer appeared to be thin enough for the maghemite nanoparticles to preserve their superparamagnetic nature. As a model the histidine-rich protein bovine serum albumin (BSA) was used. The release of the BSA bound to Zn-decorated silica-coated maghemite nanoparticles was analysed using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). We demonstrated that the bonding of the BSA to such modified magnetic nanoparticles is highly reversible and can be controlled by an appropriate change of the external conditions, such as a pH decrease or the presence/supply of other chelating compounds.
authors.affiliation: National Institute of Chemistry Slovenia, Hajdrihova 19, 1000 Ljubljana, Slovenia.
authors.forename: Marjan
authors.initials: M
authors.lastname: Bele
authors.forename: Gorazd
authors.initials: G
authors.lastname: Hribar
authors.forename: Stanislav
authors.initials: S
authors.lastname: Campelj
authors.forename: Darko
authors.initials: D
authors.lastname: Makovec
authors.forename: Vladka
authors.initials: V
authors.lastname: Gaberc-Porekar
authors.forename: Milena
authors.initials: M
authors.lastname: Zorko
authors.forename: Miran
authors.initials: M
authors.lastname: Gaberscek
authors.forename: Janko
authors.initials: J
authors.lastname: Jamnik
authors.forename: Peter
authors.initials: P
authors.lastname: Venturini
mesh_terms: D004591:Electrophoresis, Polyacrylamide Gel; D008280:Magnetics; D053758:Nanoparticles; D011485:Protein Binding; D012822:Silicon Dioxide / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D012822:Silicon Dioxide; D015032:Zinc