Synthesis and Evaluation of Fe3O4 Nanorods: Photothermal, Photo-Fenton and InVitro Biological Assessment

Abstract

IONPs are widely investigated for biomedical applications due to their magnetic, catalytic and biocompatible properties. Among these systems, anisotropic IONPs have gained increasing attention because their elongated morphology can enhance several properties such as light absorption, surface reactivity and interactions with biological systems, making them promising candidates for alternative cancer therapies. In this work, the influence of composition on the photothermal, photocatalytic and biological performance of anisotropic IONPs was investigated using two rod sizes and two iron oxide compositions. Structural characterization by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and UV-vis spectroscopy confirmed the successful synthesis of the particles. Photocatalytic experiments showed an efficient degradation of methylene blue (MB) under light irradiation and H2O2, with magnetic rods displaying significantly higher degradation activity than their precursors. Similarly, photothermal studies under 808 nm laser irradiation revealed a strong concentration-dependent heating response for the reduced IONRs, while the non-reduced rods exhibited limited heating. The biological performance of these systems was evaluated using in vitro cell viability assays with two non-tumoral (3T3 fibroblasts and HaCaT keratinocytes) cell lines and two tumoral (A431 squamous cell carcinoma and MCF-7 human breast adenocarcinoma) cell lines. Cytotoxicity assays revealed a cell-dependent response, and further photothermal treatment reduced the viability of the A431 tumoral cell line after 808 nm laser irradiation. Overall, the larger rod particles exhibited the best photothermal and photocatalytic performance, highlighting their potential as multifunctional platforms for future studies.