Induction Heating Efficiency of Water‐Dispersible Polyethylene Glycol‐Coated Cobalt Ferrite Nanoparticles Prepared Using Microwave‐Assisted Coprecipitation Technique

Controllable preparation of biocompatible magnetic nanoparticles (MNPs) with high saturation magnetization is essential for the rapid adaptation of magnetic fluid hyperthermia (MFH)‐based cancer therapy. With this objective, this work reports a microwave‐assisted synthesis of polyethylene glycol (PEG)‐coated CoFe 2 O 4 MNPs of average crystallite size of ≈13.3 ± 1.2 nm, and saturation magnetization of ≈66.6 emu g −1 . The synthesis scheme is optimized to tune the size of the MNPs to enable room temperature ferrimagnetism, which enabled hysteresis hysteresis‐mediated heating, in addition to the Brownian relaxation, when exposed to alternating magnetic field (AMF). This results in the augmentation of the MFH efficiency, sans significant agglomeration in aqueous dispersions. Fourier transform infrared spectroscopy, and dynamic light scattering confirm the presence of PEG moieties, which imparted electrostatic stabilization (zeta potential ≈−26 ± 3 mV) in aqueous medium, thereby ensuring long‐term colloidal stability, even after repeated exposures to the AMF. In vitro cytotoxicity studies indicate that the PEG‐coated MNPs are biocompatible in nature. Systematic MFH studies further reveal that the PEG‐coated CoFe 2 O 4 MNPs cause a temperature rise beyond the hyperthermia threshold of ≈42 °C within ≈120 s of bio‐medically safe AMF exposure (amplitude‐frequency product ≤ 4.2 × 10 9 Am −1 s −1 ). The highest specific absorption rate is found to be ≈326.16 ± 15.07 W g Fe −1 . These findings highlight the suitability of the of PEG‐coated CoFe 2 O 4 MNPs for MFH.