A micromagnetic perspective on magnetic particle hyperthermia
Abstract
Magnetic particle hyperthermia uses heat generated by magnetic nanoparticles under alternating magnetic fields to selectively target and treat cancer cells. Its success relies on precise temperature control in tissues, which is only measurable at the macroscale but is strongly influenced by microscale dynamics. Since direct experimental access to these dynamics is limited, computational modeling has become essential for bridging this gap. Traditional models often rely on simplified assumptions, which struggle to capture detailed particle behavior in realistic conditions. Numerical frameworks based on magnetization dynamics, such as micromagnetism, offer more accurate heat generation predictions, providing deeper insights into interparticle interactions, field effects, and thermal behavior, ultimately advancing hyperthermia treatments.
In this talk, I will present a method we developed for estimating the heat dissipation of individual, interacting particles at nonzero temperatures [1] and use it to digitally mirror aggregates observed in biological tissues to study their heat release [2]. Our findings reveal that for clusters larger than 50 particles, the average heat per particle stabilizes, enabling reliable predictions for larger aggregates. Additionally, we identified practical rules of thumb for estimating heat dissipation in fractal clusters, simplifying hyperthermia treatment planning by linking microscale behavior to macroscale heating outcomes.
Finally, recent studies demonstrate that non-harmonic waveforms, such as square or trapezoidal fields, can significantly improve heating efficiency in magnetic hyperthermia compared to traditional sinusoidal fields [3]. Our work [4] extends this by examining the individual particle heat release within clusters. We find that square wave excitations not only generate more heat but also ensure more uniform heat dissipation, reducing the risk of localized overheating or “hot spots” . These findings further strengthen the case for adopting non-harmonic excitations in practical applications, offering a clear advantage over conventional sinusoidal approaches.
Reference:
[1] J. Leliaert, J. Ortega-Julia, D. Ortega, “Individual particle heating of interacting magnetic nanoparticles at nonzero temperature” Nanoscale, 13, 14734-14744 (2021)
[2] J. Ortega-Julia, D. Ortega, J. Leliaert, “Estimating the heating of complex nanoparticle aggregates for magnetic hyperthermia” Nanoscale, 15, 10342-10350 (2023)
[3] P. Allia, G. Barrera, and P. Tiberto, “Nonharmonic driving fields for enhancement of nanoparticle heating efficiency in magnetic hyperthermia,” Physical Review Applied 12, 034041 (2019)
[4] J. Ortega-Julia, D. Ortega, J. Leliaert, “Magnetic heating of interacting nanoparticles under different driving field waveforms” Journal of Applied Physics, 135, 054301 (2024)
We invite you to follow the seminar online in case you cannot make it in person.
- Meeting number: 2780 541 4369
- Meeting password: 5QGyZqzep23