Silica-coated magnetic nanorods with zwitterionic surface functionalization to overcome non-specific protein adsorption
Sirine El Mousli, Yves Dorant, Enzo Bertuit, Emilie Secret, Jean‐Michel Siaugue
Abstract
Anisotropic magnetic nanoparticles are receiving growing interest for biomedical applications due to their interesting properties, particularly for MRI and magnetic hyperthermia. In this work, a two-step, relatively simple synthesis pathway of magnetite nanorods was optimised. A ligand from the catechol family, known for its high iron oxide surface affinity, was used to transfer them into aqueous phase. The magnetite nanorods were then coated with a layer of fluorescent silica, whose surface was functionalised in two ways: either by short poly(ethylene glycol) (PEG) chains or by sulfobetaine zwitterionic molecules. A wide range of techniques were used to thoroughly characterise their physical structure, magnetic properties and dispersion characteristics. Finally, a study of the adsorption of a fluorescent model protein revealed that zwitterionic sulfobetaine molecules were more effective than PEG chains in limiting the non-specific adsorption of this protein.