Speakers - 2026

Ferrite-based magnetic nanoparticles (MNPs) represent a novel class of engineered nanomaterials with growing attention across disciplines such as physics, chemistry, biology, medicine, materials science, and engineering. Their exceptional physical, optical, magnetic, and electrical properties make them highly attractive for diverse applications ranging from magnetic fields and microwave absorption to biomedical uses. Composed primarily of iron oxides in combination with metals such as manganese and zinc, these nanoparticles exhibit strong magnetic properties that open avenues for magnetic resonance imaging, targeted drug delivery, and cancer therapy through magnetic hyperthermia. However, the very features that make ferrite nanoparticles so promising also raise concerns regarding their interactions with biological systems and potential safety implications. Although publications related to the synthesis and application of various MNPs have increased tremendously in the last few years, the importance of conducting comprehensive safety assessments of MNPs has been significantly overlooked. To address this gap, in the present study, we investigated the potential genotoxic activity of three MNPs, citric-coated γFe2O3, Zn0.7Fe2.3O4, and Mn0.4Fe2.6O4, in vitro, thereby contributing to a better understanding of their possible health risks in biomedical applications. Our study was conducted using a 3D cell model (spheroids) derived from the human hepatocellular carcinoma cell line (HepG2). By using 3D cell models, we can better mimic in vivo physiology, providing more reliable insights into the safety and toxicological profiles of nanoparticles, ultimately improving the predictive power of nanotoxicology research and guiding the development of safer nanotechnologies. Cytotoxicity was evaluated by measuring intracellular ATP levels, while genotoxicity was assessed by the comet assay and flow cytometry targeting γH2AX (for double-strand breaks) and pH3 (for mitotic cells), markers of clastogenic and aneugenic activity, respectively. In addition, generation of reactive oxygen species (ROS) was measured by DCFH-DA assay, and malondialdehyde (MDA), as a marker of lipid peroxidation, was used to further evaluate the oxidative stress. Furthermore, the influence on DNA damage and oxidative stress response genes was analysed by qPCR. To evaluate nanoparticle uptake and localisation at both the spheroid and single cell level, transmission electron microscopy (TEM) was used. Three-day-old spheroids were exposed to graded concentrations of MNPs (up to 250 µg/mL) for 2 to 96 hours, depending on the endpoint. Zn0.7Fe2.3O4 and Mn0.4Fe2.6O4 exhibited higher cytotoxicity than γFe2O3 at 24 and 96 hours. While the comet assay indicated significant DNA damage after 96 hours, no increase in γH2AX or pH3 levels was detected. A dose- and time-dependent increase in ROS generation was observed only for γFe2O3, while there was no significant increase in MDA formation. Gene expression analysis revealed no significant deregulation across samples and concentrations at 24 hours; however, after 96 hours, a broader deregulation pattern emerged, most notably an upregulation of BCL2 in samples Zn0.7Fe2.3O4 and Mn0.4Fe2.6O4. TEM analysis revealed limited penetration of MNPs, mainly restricted to outer spheroid layers. Overall, ferrite nanoparticle effects were both time- and composition-dependent, underscoring the need for extended exposure studies in 3D cell models. Further research is required to clarify long-term impacts and guide the safe biomedical use of these materials.

The audience take away from presentation:

• While nanomaterial innovation and use are rapidly accelerating, with new materials being developed at an exponential rate across many industries, safety assessment is not keeping pace with this growth, creating a critical knowledge and regulatory gap.
• Understanding nanomaterial toxicity is essential to protect human health and the environment – nanotechnology goes hand in hand with nanotoxicology.
• Advanced in vitro models and testing approaches are critical tools for improving the relevance, speed, and ethical standards of nanotoxicology research.
• Strengthening testing frameworks is urgent to ensure responsible and sustainable nanotechnology development.