In-vitro cytotoxicity of biocompatible Fe-Ti-Nb-B magnetic nanoparticles in alternating magnetic fields

The need for curing various incurable diseases is demanding not only new types of materials, which preferably will mimic the nature functionalities, but also the understanding of their properties in relation with their microstructure. In this context, the use of magnetic hyperthermia for curing cancer appears to be an extremely viable one. Fe oxides nanoparticles with superparamagnetic behavior (SPIONs) are extensively used in clinical tests involving magnetic hyperthermia. Among the concerns about SPIONs use in magnetic hyperthermia tests, one should mention: the preservation of the stability of Fe oxide NPs against oxidation, the limitations imposed to stop the heating of Fe-oxides (mainly Fe₃O₄) at moderate temperatures (below 47°C), and, most importantly, the capacity to retain the temperature in the range of 41-46°C, which requires a very rigorous control of the power of the high frequency generator. To overcome these issues, we have developed a new type of ferromagnetic nanoparticles (the saturation magnetization is higher compared with Fe-oxides and the hysteresis losses are reduced as well), with the nominal composition Fe_79.7-xTi_xNb_0.3B₂₀ (x = 12÷20 at.%), with low Curie temperatures compared with SPIONs, which can be tailored easily and precisely in the 0-70°C by modifying the Ti content, with an accuracy of less than 1°C, more suitable for self-regulating magnetic hyperthermia.