Synthesis of Ca2+ substituted cobalt zinc ferrite nanoparticles for magnetic induction hyperthermia

Magnetic induction hyperthermia has great potential in cancer treatment. However, the low heating efficiency of the magnetic nanoparticles (MNPs) with self-regulated temperature capability limits its clinical application. Here, the self-regulated temperature MNPs of Ca-doped Co-Zn ferrite MNPs (CaxCo0.5-xZn0.5Fe2O4, 0 <= x <= 0.20), with high heating efficiency, were successfully synthesized by co-precipitation method followed by heat treatment. Noticeably, the x = 0.1 suspension sample can self-stabilize the temperature for high-temperature hyperthermia, whereas x = 0.2 suspension sample can self-stabilize the temperature suitable for conventional hyperthermia under an alternating magnetic field of 32 kA/m and 100 kHz. In vitro cell experiments indicate that the MNPs have good biocompatibility. The results demonstrate that optimized saturation magnetization (sigma(S)) and tunable Curie temperature (Tc) enhance both the heating efficiency and thermal safety of the nanoparticles during magnetic induction hyperthermia treatment.