title: Taking advantage of unspecific interactions to produce highly active magnetic nanoparticle-antibody conjugates.
abstract: Several strategies for linking antibodies (Abs) through their Fc region in an oriented manner have been proposed at the present time. By using these strategies, the Fab region of the Ab is available for antigen molecular recognition, leading to a more efficient interaction. Most of these strategies are complex processes optimized mainly for the functionalization of surfaces or microbeads. These methodologies imply though the Ab modification through several steps of purification or the use of expensive immobilized proteins. Besides, the functionalization of magnetic nanoparticles (MNPs) turned out to be much more complex than expected due to the lack of stability of most MNPs at high ionic strength and non-neutral pH values. Therefore, there is still missing an efficient, easy and universal methodology for the immobilization of nonmodified Abs onto MNPs without involving their Fab regions during the immobilization process. Herein, we propose the functionalization of MNPs via a two-steps strategy that takes advantage of the ionic reversible interactions between the Ab and the MNP. These interactions make possible the orientation of the Ab on the MNP surface before being attached in an irreversible way via covalent bonds. Three Abs (Immunoglobulin G class) with very different isoelectric points (against peroxidase, carcinoembryonic antigen, and human chorionic gonadotropin hormone) were used to prove the general applicability of the strategy here proposed and its utility for the development of more bioactive NPs.
authors.affiliation: Biofunctionalization of Nanoparticles and Surfaces (BioNanoSurf), Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, Campus Río Ebro, Edifício I+D, Mariano Esquillor, s/n, 50018 Zaragoza, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Puertas
authors.forename: Pilar
authors.initials: P
authors.lastname: Batalla
authors.forename: María
authors.initials: M
authors.lastname: Moros
authors.forename: Ester
authors.initials: E
authors.lastname: Polo
authors.forename: Pablo
authors.initials: P
authors.lastname: Del Pino
authors.forename: José M
authors.initials: JM
authors.lastname: Guisan
authors.forename: Valeria
authors.initials: V
authors.lastname: Grazú
authors.forename: Jesús M
authors.initials: JM
authors.lastname: de la Fuente
mesh_terms: D000327:Adsorption; D000906:Antibodies / Q000737:chemistry*; D015374:Biosensing Techniques; D006063:Chorionic Gonadotropin / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D018796:Immunoconjugates / Q000737:chemistry; D007128:Immunoglobulin Fragments / Q000737:chemistry; D007477:Ions; D008027:Light; D008280:Magnetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D012542:Scattering, Radiation; D013499:Surface Properties
chemical_list: D000906:Antibodies; D006063:Chorionic Gonadotropin; D018796:Immunoconjugates; D007128:Immunoglobulin Fragments; D007477:Ions