Highly Hydrophilic Oleylamine-Modified Superparamagnetic Iron Oxide Nanoparticles for Biomedical Applications

Superparamagnetic iron oxide nanoparticles (SPIONs) are becoming important vehicles for biomedical applications. This study demonstrates a new strategy based on a “haircut” reaction, aiming at the design of highly hydrophilic and functional nanoparticles. The as-synthesized SPIONs have a diameter of ∼4 nm and reveal super-organophilic behavior due to their surface modification by oleylamine molecules present on their surface (o-SPIONs). The “trimming”, which is applied on the oleylamine molecule double bond, produces shorter chains terminated by carboxyl groups, with the resulting nanoparticles exhibiting high hydrophilicity, dispersibility in water, and functionality (h-SPIONs). The biological behavior of h-SPIONs is studied against three different cell lines and reveals a selective cytotoxic effect against cancer cells. This novel method of engineering the surface properties of nanoparticles can lead to the development of a new generation of functional nanomaterials. In addition, h-SPIONs can evolve into a new and expanding family of magnetic nanomaterials in future biomedical systems.