Magnetic hyperthermia with magnetite nanoparticles: electrostatic and polymeric stabilization

In this work, magnetic hyperthermia, i.e., heating induced by an alternating magnetic field acting on a magnetic suspension, is considered in three main aspects. The first one regards the implementation of a simple device for producing AC magnetic fields. The second contribution concerns the comparison of the hyperthermia response (measured by the specific absorption rate (SAR)) of magnetite nanoparticles of two different sizes and of raw particles vs. polyelectrolyte-coated ones. An improvement is observed of the SAR values when the pH is fixed away from the isoelectric point or when the ionic strength is kept at low values. The addition of a polymer enhances significantly the stability of the suspensions and so does with the SAR values. Finally, we describe the implementation of a sort of magnetic hyperthermia applicator, avoiding the necessity of placing the magnetic sample inside the coil and making it of more practical use.