An original route to stabilize and functionalize magnetite nanoparticles for theranosis applications

A versatile method for the introduction of cyano groups onto the surface of iron oxide nanoparticles has been developed. This protocol is based on the hydrolysis and the condensation of cyanoethyltrimethoxysilane (CES) on the magnetite surface. The optimal concentration of silane coupling agent was determined ([Fe]/[CN] ratio=0.4) in order to obtain an appropriate surface density of activating groups on the nanoparticles. The size distribution of the particles was also optimized by a magnetic size sorting procedure. An adequate surface with cyano groups could facilitates their use in biomedical applications by improving the cellular labeling and the cell targeting.

Research Highlights
► Cyano groups facilitate the bioapplications.
► Magnetic size sorting improves the monodispersity.
► The stabilization can be controlled by relaxometry.