Speaker
Description
Nanotechnology in biomedical applications has enabled the creation of novel systems with unique characteristics that combine the properties of biomolecules and iron oxide nanoparticles (IONPs) [1], enhancing treatment effectiveness and reducing costs. IONPs, valued for their specific magnetic properties and low toxicity, offer a promising approach to overcoming challenges in magnetic hyperthermia. However, their practical application is hindered by low heating power (per unit mass of nanoparticles), which contradicts the expected superparamagnetic behavior of IONPs. This discrepancy is attributed to polydispersity in IONP sizes within real samples or altered magnetic properties due to finite size effects. The solution to this problem is multicore magnetic IONPs resembling flower-like structures. In these nanoflowers (NFs), IONP cores are embedded within a polymer or organic coating, and their unique structure significantly enhances magnetic properties, including strong magnetic responses arising from complex internal magnetic ordering [2].
In this study, single-core and multicore IONPs were synthesized using two methods: coprecipitation and the polyol method. A comprehensive physicochemical characterization of the synthesized nanoparticles was performed to determine their structural, morphological, magnetic, and surface properties. The TEM images revealed that single-core IONPs were roughly spherical with an average diameter of $10$ nm, while NFs displayed a flower-like morphology with a diameter of $30$ nm. Additionally, the surface area and porosity of the samples were analyzed using nitrogen physisorption measurements at $77$ K, based on adsorption-desorption isotherms. The superparamagnetic behavior of both IONPs and NFs at room temperature was confirmed using a SQUID magnetometer. Moreover, the induction heating ability of both samples under an alternating magnetic field was studied by specific absorption rate (SAR) measurements. The results showed that SAR values increased with the applied magnetic field $H$, reaching up to $\approx 7.9$ $\mathrm{kA\,m^{-1}}$. Notably, NFs exhibited significantly higher SAR values than single-core IONPs, confirming their potential as efficient nano-heaters for magnetic hyperthermia applications.
Acknowledgements
This work was funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09I03-03-V04-00296.
References
[1] Y. Q. Meng et al., “Recent trends in preparation and biomedical applications of iron oxide nanoparticles,” Journal of Nanobiotechnology, vol. 22, no. 1. Springer Science and Business Media LLC, Jan. 08, 2024. https://doi.org/10.1186/s12951-023-02235-0
[2] A. A. Kuznetsov et al., “Multicore-based ferrofluids in zero field: initial magnetic susceptibility and self-assembly mechanisms,” Soft Matter, vol. 19, no. 24. Royal Society of Chemistry (RSC), pp. 4549–4561, 2023. https://doi.org/10.1039/d3sm00440f
