Cobalt-ferrite magnetic nanoparticles (MNPs) exhibiting three distinct morphologies: spherical, cubic, and octopod-like, with perfect shape resolution and a very narrow size distribution, were successfully synthesised by the thermal decomposition method. The influence of particle shape on the structural, magnetic, and magneto-thermal properties was systematically investigated. The magneto-thermal performance was evaluated under AC fields with varying amplitudes and frequencies and quantified using the SAR and ILP parameters. A pronounced dependence of heating efficiency on particle morphology was observed. Cubic nanoparticles exhibited the highest magneto-thermal performance, reaching SAR values up to 411 W/g at applied field ∼20 kA/m and 728 kHz, whereas spherical nanoparticles showed negligible heating, and octopod particles exhibited intermediate performance. These differences are interpreted within the framework of linear response theory, highlighting the roles of effective magnetic anisotropy and interparticle interactions in governing the magneto-thermal response. The response of A549 and HT-29 cancer cells to cobalt-ferrite nanoparticles was found to be strongly concentration-dependent. At a concentration of 100 µg/mL, cubic nanoparticles exhibited the weakest inhibitory effect, while lower concentrations were well tolerated without a significant morphology-dependent effect. Overall, the results underline the importance of morphology control in the design of efficient and biocompatible cobalt-ferrite nanoparticles for magnetic hyperthermia applications.
Nagy et al. (2026) studied this question.