Non-contact Mn1-xNixFe2O4 ferrite nano-heaters for biological applications - heat energy generated by NIR irradiation

Mn1-xNixFe2O4 nanoparticles with primary particle size of 6 nm +/- 4 nm were synthesized using fast and effective microwave stimulated technique without addition of surfactants or other specific agents to open more flexible post-surface modification potential. Structural, chemical and morphological characterization were performed using XRD, SEM-EDS and TEM techniques. DLS and absorption measurements were performed in order to evaluate hydrodynamic size of particles/objects and nanoparticles dispersion stability upon addition of stabilizing agents in water. The J774. E murine macrophage and U2OS human osteosarcoma cells exposed to particle dispersions revealed high loading of macrophages and moderate loading of osteosarcoma cells. Difference was ascribed to phagocytic activity of macrophages and their explicit role in elimination of particulate matter under in vivo conditions. It was shown that the effective heat generation can be achieved with Mn1-xNixFe2O4 magnetic ferrites by using NIR light irradiation instead of AC magnetic field reaching temperatures suitable for application in hyperthermia-based therapies.