Enhancing magnetic hyperthermia in ferrite nanoparticles through shape anisotropy and surface hybridization

Magnetic hyperthermia has been studied for the past two decades in cancer treatments as the local heat generated by magnetic nanoparticles under applied alternating magnetic fields is sufficient to kill cancer cells. More recently, it has been explored for controlling biological signaling through heat-sensitive transmembrane channels. It is of great interest to produce magnetic nanoparticles with high heat transducing efficiency to minimize potential off-target heating effects. Here, we describe shape anisotropy and particle hybridization as possible routes to augment magnetic hyperthermia in ferrite nanoparticles. Zinc substituted magnetite core and core-shell cubic nanoparticles with different sizes were synthetized. It was found that nanoparticles shape and composition are altered from cubic to flower-like, and to a more franklinite rich phase as size increased. Hybridization with a cobalt shell allowed to enhance nanoparticle magnetic coercivity and specific power loss. The optimized core-shell nanoparticles were tested to induce cellular activity in hippocampal neurons. TOPICAL HEADING Inorganic Materials: Synthesis and Processing.