Self-regulated cobalt zinc ferrite system as a potential nanoplatform for the synergistic effect of hyperthermia-chemo agent for cancer therapy

Magnetic hyperthermia (MH) has been studied for almost seventy-five years, but its efficacy in clinical applications is still fiercely contested. Despite this, few magnetic nanosystems are approved for clinical usage due to their strong affinity as drug carriers. The most important condition for hyperthermia applications for successful cancer therapy is magnetic nanoparticles with a controlled heating pattern (42-46 °C) for a prolonged timeframe. In the current study, cobalt-zinc nanoferrites (MNPs) having a Curie temperature of 46 ℃ with a tunable heating profile was loaded with Doxorubicin (DOX) through a surface conjugation technique (DOX-Cs-MNPs), and characterized by using multiple techniques. The magnetic hyterises (M-H) curves revealed the occurrence of superparamagnetism in the MNPs with extremely low coercivity; further, the DOX-loaded nanoparticles exhibited enhanced saturation magnetization. More importantly, the MNPs showed that they could maintain a therapeutic temperature for an indefinite amount of time. High drug loading affinity (86 %) was observed on MNPs with pH and temperature-controlled release. Under in vitro conditions, the biocompatible DOX-Cs-MNPs caused substantial apoptosis in MCF-7 cells (72 %) with overall cell death of 95 %. The distinctive MNPs thus have the potential to be used in clinical applications.