Magnetic fluid hyperthermia (MFH) is a minimally invasive procedure that destroys cancer cells. It is based on a superparamagnetic heat phenomenon and consists in feeding a ferrofluid into a tumor, and then applying an external electromagnetic field, which leads to apoptosis. The strength of the magnetic field, optimal dose of the ferrofluid, the volume of the tumor and the safety standards have to be taken into consideration when MFH treatment is planned. In this study, we have presented the novel complementary investigation based both on the experiments and numerical methodology connected with female breast cancer. We have conducted experiments on simplified female breast phantoms with numerical analysis and then we transferred the results on an anatomically-like breast model.

The manipulation of magnetic nanoparticles (MNPs) using an external magnetic field, has been successfully demonstrated in various biomedical applications. Some have utilised this non-invasive external stimulus and there is an potential to build on this platform. The focus of this study is to understand the manipulation of MNPs by a time-varying static magnetic field and how, at different frequencies and displacement, this can alter cellular function. Here we explore, using numerical modeling, the physical mechanism which underlies this process, and we discuss potential improvements for its use in biomedical applications. From our data and other related studies, we infer that such phenomenon largely depends on the magnetic field gradient, magnetic susceptibility and size of the MNPs, magnet array oscillating frequency, viscosity of the medium surrounding MNPs, and distance between the magnetic field source and MNPs. Additionally, we demonstrate cytotoxicity in neuroblastoma (SH-SY5Y) and hepatocellular carcinoma (HepG2) cells in vitro induced by MNPs exposed to a magnetic field gradient and oscillating at various frequencies and displacement amplitudes. Even though this technique reliably produces MNP endocytosis and/or cytotoxicity, a better understanding is required to develop this system for precision manipulation of MNPs, ex vivo.

The paper presents the investigation of magnetic nanoparticles (MNPs) dedicated to hyperthermia application. The crystal structure and size distributions have been determined by means of transmission electron microscope (TEM) and X-ray diffraction (XRD). Magnetic properties of the nanoparticles were tested by Mössbauer spectroscopy together with calorimetric experiments. The Mössbauer spectroscopic study of MNPs revealed the existence of a superparamagnetic phase. The relative contribution of the relaxing component to the total spectrum at room temperature was about 10%. The heating effect of these MNPs under alternating magnetic field was examined. The temperature increase has reached 5°C in 10 min. The preliminary temperature rise suggests that the investigated materials are applicable for hyperthermia.

Electromagnetic hyperthermia as a potent adjuvant for conventional cancer therapies can be considered valuable in modern oncology, as its task is to thermally destroy cancer cells exposed to high-frequency electromagnetic fields. Hyperthermia treatment planning based on computer in silico simulations has the potential to improve the localized heating of breast tissues through the use of the phased-array dipole applicators. Herein, we intended to improve our understanding of temperature estimation in an anatomically accurate female breast phantom embedded with a tumor, particularly when it is exposed to an eight-element dipole antenna matrix surrounding the breast tissues. The Maxwell equations coupled with the modified Pennes’ bioheat equation was solved in the modelled breast tissues using the finite-difference time-domain (FDTD) engine. The microwave (MW) applicators around the object were modelled with shortened half-wavelength dipole antennas operating at the same 1 GHz frequency, but with different input power and phases for the dipole sources. The total input power of an eight-dipole antenna matrix was set at 8 W so that the temperature in the breast tumor did not exceed 42 °C. Finding the optimal setting for each dipole antenna from the matrix was our primary objective. Such a procedure should form the basis of any successful hyperthermia treatment planning. We applied the algorithm of multi for multi-objective optimization for the power and phases for the dipole sources in terms of maximizing the specific absorption rate (SAR) parameter inside the breast tumor while minimizing this parameter in the healthy tissues. Electro-thermal simulations were performed for tumors of different radii to confirm the reliable operation of the given optimization procedure. In the next step, thermal profiles for tumors of various sizes were calculated for the optimal parameters of dipole sources. The computed results showed that larger tumors heated better than smaller tumors; however, the procedure worked well regardless of the tumor size. This verifies the effectiveness of the applied optimization method, regardless of the various stages of breast tumor development.

Purpose: We describe the design and application of a new apparatus for applying Radiofrequency (RF) electromagnetic fields to cells in culture on a microscope stage. This new design enables real-time studies of the actuation of magnetic nanoparticles bound to membrane receptors or internalised within cells together with the study of magnetic fluid hyperthermia (MFH)-associated effects. Materials and methods: RF coils were fabricated and electromagnetic simulations were performed along with compatibility evaluations and calorimetric experiments using this apparatus at discreet frequencies between 100 kHz and 1 MHz. Cell killing via MFH was investigated in a neuroblastoma tumour cell line. Results: Simulations and evaluations showed that the field intensity and homogeneity experienced by the cells within the chamber is best with a planar coil configuration. The incubation chamber was suitable for cell culture and the design was compatible with mountings on different makes of microscopes as it mimics a standard 96/24/6 tissue-culture well plate. Successful calorimetric and MFH cytotoxicity proof-of-principle experiments were performed and are presented. Conclusions: We conclude from these experiments that alternating magnetic field (AMF)-mediated activation and magnetic fluid hyperthermia (MFH) research will benefit from this RF coil that fits inside an incubation chamber, mounted onto a microscope. This new design could be used to assist real-time MFH studies in vitro.