Construction of a variable frequency ac magnetic field device and magnetic hyperthermia applications on ferrite nanoparticles

Öztürk, Seçkin
Magnetic hyperthermia is a promising therapeutic method for cancer treatment. This method is based on the intratumoral deposition of biocompatible magnetic nanoparticles followed by exposure to a high-frequency electromagnetic field. Research in this field continues to intensify. Within the scope of this thesis, a variable frequency magnetic hyperthermia system has been developed for research in magnetic fluid hyperthermia. The developed system can apply an alternative magnetic field in the frequency range of 20 to 80 kHz with amplitudes up to 2 kA/m. With a temperature measurement accuracy of 0.1°C and software developed during operation, the SAR (Specific Absorption Rate) values can be measured with high accuracy even under low heating conditions. Thus, an experimental setup has been obtained that allows the testing of the Linear Response Theory under low magnetic fields. The magnetic nanoparticles required for testing the developed system were also produced within the scope of this study and characterized using chemical, crystallographic, and magnetic methods. The characterization results indicated a wide distribution of magnetic properties for the obtained materials. The produced and characterized particles were subjected to experiments using the developed hyperthermia system. The results obtained from the experiments were compared with physical models to confirm the functionality of the system. In hyperthermia studies, the multitude of parameters that can affect heating and their direct or indirect interdependencies make it challenging to draw systematic conclusions from experimental studies. To overcome this challenge, it is necessary to increase the diversity of experimental studies. Although there are numerous theoretical studies on the Linear Response Theory under low magnetic fields, experimental studies are rarely encountered. It is believed that the hyperthermia system developed during the study will contribute diversity of experiments in this research area. With its low magnetic field intensity and precise temperature measurement capabilities, the system could provide insights into challenging aspects that are often difficult to explain.
Citation Formats
S. Öztürk, “Construction of a variable frequency ac magnetic field device and magnetic hyperthermia applications on ferrite nanoparticles,” Ph.D. - Doctoral Program, Middle East Technical University, 2023.