Physicochemical Properties of Magnetic Nanoparticles: Implications for Biomedical Applications In Vitro and In Vivo

Magnetic and superparamagnetic iron oxide nanoparticles are emerging as promising candidates for various applications in biology and medicine, and especially in oncology. These applications, however, require that a specific set of physical, chemical, and biological properties be combined in a given sample of nanoparticles for them to act as intended. Some of these properties are fundamental: They strictly determine the nanoparticles' behavior both in vitro and in vivo. These properties are the charge, the solution stability and zeta potential, and the coating of the nanoparticles. A certain combination of these properties may satisfy a researcher in an in vitro study, but other properties should also be considered when in vivo applications are planned. For in vivo experiments, additional determinants of the quality of nanoparticles are their size, shape, modifications with targeting moieties, and degradation/excretion pathways. All these properties are in the focus of the present review.