Optimum nanoscale design in ferrite based nanoparticles for magnetic particle hyperthermia

Abstract

The study demonstrates the multiplex enhancement of the magnetic hyperthermia response in ferrites by nanoscale design and tuning without sparing the biocompatibility of iron-oxide. We propose core/shell nanoparticles with a 7–9 nm ferrite core, either magnetically soft MnFe₂O₄ or hard CoFe₂O₄, encapsulated by a 2–3 nm Fe₃O₄ shell providing a core/shell interface. In this case, the exchange interaction between core and shell dramatically affects the macroscopic magnetic behavior and, at the same time, a biocompatible shell prevents interactions of the toxic cores with their environment. The tunable, yet superior, magnetic hyperthermia response is proven by an increase of the specific loss power by a factor of 24 for CoFe₂O₄–Fe₃O₄ core/shell particles. This gain is directly connected with the magnetic coupling strength at the core/shell interface and opens the possibility of further optimization.