Towards a versatile platform based on magnetic nanoparticles for in vivo applications

Magnetic nanoparticles have attracted wide attention because of their usefulness as contrast agents for magnetic resonance imaging (MRI) or colloidal mediators for cancer magnetic hyperthermia. This paper examines these in vivo applications through an understanding of the problems involved and the current and future possibilities for resolving them. A special emphasis is made on magnetic nanoparticle requirements from a physical viewpoint, the factors affecting their biodistribution and the solutions envisaged for enhancing their half-life in the blood compartment and targeting tumour cells. Then, our synthesis strategies are presented and focused on covalent platforms based on maghemite and dextran and capable to be tailorderivatized by surface molecular chemistry. The opportunity of taking advantage of temperature-dependence of magnetic properties of some complex oxides for controlling the in vivo temperature is also discussed.