Magnetic Nanoparticle Nanoformulations for Alternative Therapy of Cancer by Magnetic/Superparamagnetic Hyperthermia

Abstract

Superparamagnetic hyperthermia, obtained by increasing the temperature to 42-43 °C in tumor tissue where magnetic nanoparticles are found, as a result of superparamagnetic relaxation, following the application of an external alternating magnetic field at a frequency of hundreds of kiloherz, is an alternative method that is noninvasive and apparently lacking toxicity and that has real potential as a cancer therapy. However, magnetic nanoparticles used as thermal mediators play a very important role in the efficacy of the method in the irreversible destruction of tumors. The NPs must meet a number of physical and magnetic characteristics in order to obtain the maximum hyperthermal effect, but also a reduced or even lack of toxicity on healthy cells. This chapter presents just this aspect of biocompatibility/cytotoxicity and nanoformulations of magnetic nanoparticles for their use in superparamagnetic hyperthermia. We will consider the recent nanoformulations that could be used successfully in superparamagnetic hyperthermia, tested in vitro and in vivo, as well as current trends in dual therapy, thermochemotherapy, or thermoradiotherapy.