Magnetic Hyperthermia Research Articles

Numerical simulation of heat transfer and nanoparticle transport in a nanofluid within a tumour surrounding a blood vessel

A Newtonian nanofluid containing suspended nanoparticles can substantially improve heat transfer due to enhanced energy transport mechanisms. This theoretical study investigates heat and mass transfer in biological tissues using such a nanofluid under a magnetic field. These properties have promising medical and engineering applications. The nonlinear governing equations were transformed into ordinary differential equations using similarity variables and numerically solved with MATLAB boundary value problem solver bvp4c, subject to appropriate boundary conditions. Results demonstrated increasing the heat source parameter dramatically raised tumor interstitial temperature. This heating, along with improved nanoparticle accumulation within the tumor due to the thermal effects, are together essential for effective hyperthermia treatment. The model provides new insights into tuning heat and mass transport mechanisms in biological tissues via nanofluids for therapeutic applications. Therefore, the findings of this study may improve the efficacy of thermal therapy in treating cancer.

NIR-Responsive Methotrexate-Modified Iron Selenide Nanorods for Synergistic Magnetic Hyperthermic, Photothermal, and Chemodynamic Therapy.

Breast cancer is a malignant tumor with a high mortality rate among women. Therefore, it is necessary to develop novel therapies to effectively treat this disease. In this study, iron selenide nanorods (FeSe2 NRs) were designed for use in magnetic hyperthermic, photothermal, and chemodynamic therapy (MHT/PTT/CDT) for breast cancer. To illustrate their efficacy, FeSe2 NRs were modified with the chemotherapeutic agent methotrexate (MTX). MTX-modified FeSe2 (FeSe2-MTX) exhibited excellent controlled drug release properties. Fe2+ released from FeSe2 NRs induced the release of •OH from H2O2 via a Fenton/Fenton-like reaction, enhancing the efficacy of CDT. Under alternating magnetic field (AMF) stimulation and 808 nm laser irradiation, FeSe2-MTX exerted potent hyperthermic and photothermal effects by suppressing tumor growth in a breast cancer nude mouse model. In addition, FeSe2 NRs can be used for magnetic resonance imaging in vivo by incorporating their superparamagnetic characteristics into a single nanomaterial. Overall, we presented a novel technique for the precise delivery of functional nanosystems to tumors that can enhance the efficacy of breast cancer treatment.

Economic and Accessible Portable Homemade Magnetic Hyperthermia System: Influence of the Shape, Characteristics and Type of Nanoparticles in Its Effectiveness.

Currently, one of the main causes of death in the world is cancer; therefore, it is urgent to obtain a precocious diagnosis, as well as boost research and development of new potential treatments, which should be more efficient and much less invasive for the patient. Magnetic hyperthermia (MH) is an emerging cancer therapy using nanoparticles, which has proved to be effective when combined with chemotherapy, radiotherapy and/or surgery, or even by itself, depending on the type and location of the tumor's cells. This article presents the results obtained by using a previously developed economic homemade hyperthermia device with different types of magnetite nanoparticles, with sizes ranging between 12 ± 5 and 36 ± 11 nm and presenting different shapes (spherical and cubic particles). These magnetic nanoparticles (MNPs) were synthesized by three different methods (co-precipitation, solvothermal and hydrothermal processes), with their final form being naked, or possessing different kinds of covering layers (polyethylene glycol (PEG) or citric acid (CA)). The parameters used to characterize the heating by magnetic hyperthermia, namely the Specific Absorption Rate (SAR) and the intrinsic loss power (ILP), have been obtained by two different methods. Among other results, these experiments allowed for the determination of which synthesized MNPs showed the best performance concerning hyperthermia. From the results, it may be concluded that, as expected, the shape of MNPs is an important factor, as well as the time that the MNPs can remain suspended in solution (which is directly related to the concentration and covering layer of the MNPs). The MNPs that gave the best results in terms of the SAR were the cubic particles covered with PEG, while in terms of total heating the spherical particles covered with citric acid proved to be better.

Effect of heavy Dy3+ doping on the magnetic, structural, morphological, and optical characteristics of CuDyxFe2-xO4 nanoparticles

The present study explored the impacts of dysprosium (Dy³⁺) doping on the structure, optical, and magnetic characteristics of CuDyxFe2-xO4 nanospinel ferrites synthesized via a hydrothermal method. X-ray diffraction revealed a tetragonal spinel matrix with increasing Dy³⁺ content, accompanied by a secondary Dy2O3 phase at higher dopant levels for x ≥ 0.1. Crystallite size and microstrain increased with doping, while infrared spectroscopy confirmed the spinel structure and distinct vibrational modes. Interestingly, saturation magnetization displayed a non-monotonic trend, first rising due to spin polarization and cation redistribution, then decreasing with higher Dy³⁺ content attributable to the Dy2O3 phase and larger grains. Coercivity exhibited a maximum at x = 0.2, reflecting the interplay between magnetocrystalline anisotropy, canting angles, and domain wall pinning. These findings highlight the complex interplay between Dy³⁺ doping and the resulting properties, paving the way for tailored CuDyxFe2-xO4 nanospinel ferrites functionalities. . Further research involving advanced techniques and targeted dopant levels holds promise for optimizing properties for diverse technological applications such as magnetic storage, microwave devices, sensors, and hyperthermia treatment.

Model predictive control (MPC) applied to a simplified model, magnetic nanoparticle hyperthermia (MNPH) treatment process

Magnetic nanoparticle hyperthermia (MNPH) has emerged as a promising cancer treatment that complements conventional ionizing radiation and chemotherapy. MNPH involves injecting iron-oxide nanoparticles into the tumor and exposing it to an alternating magnetic field (AMF). Iron oxide nanoparticles produce heat when exposed to radiofrequency AMF due to hysteresis loss. Minimizing the non-specific heating in human tissues caused by exposure to AMF is crucial. A pulse-width-modulated AMF has been shown to minimize eddy-current heating in superficial tissues. This project developed a control strategy based on a simplified mathematical model in MATLAB SIMULINK® to minimize eddy current heating while maintaining a therapeutic temperature in the tumor. A minimum tumor temperature of 43 [°C] is required for at least 30 [min] for effective hyperthermia, while maintaining the surrounding healthy tissues below 39 [°C]. A model predictive control (MPC) algorithm was used to reach the target temperature within approximately 100 [s]. As a constrained MPC approach, a maximum AMF amplitude of 36 [kA/m] and increment of 5 [kA/m/s] were applied. MPC utilized the AMF amplitude as an input and incorporated the open-loop response of the eddy current heating in its dynamic matrix. A conventional proportional integral (PI) controller was implemented and compared with the MPC performance. The results showed that MPC had a faster response (30 [s]) with minimal overshoot (1.4 [%]) than PI controller (115 [s] and 5.7 [%]) response. In addition, the MPC method performed better than the structured PI controller in its ability to handle constraints and changes in process parameters.

Magnetic nanoparticles in square-wave fields for breakthrough performance in hyperthermia and magnetic particle imaging

Driving immobilized, single-domain magnetic nanoparticles at high frequency by square wave fields instead of sinusoidal waveforms leads to qualitative and quantitative improvements in their performance both as point-like heat sources for magnetic hyperthermia and as sensing elements in frequency-resolved techniques such as magnetic particle imaging and magnetic particle spectroscopy. The time evolution and the frequency spectrum of the cyclic magnetization of magnetite nanoparticles with random easy axes are obtained by means of a rate-equation method able to describe time-dependent effects for the particle sizes and frequencies of interest in most applications to biomedicine. In the presence of a high-frequency square-wave field, the rate equations are shown to admit an analytical solution and the periodic magnetization can be therefore described with accuracy, allowing one to single out effects which take place on different timescales. Magnetic hysteresis effects arising from the specific features of the square-wave driving field results in a breakthrough improvement of both the magnetic power released as heat to an environment in magnetic hyperthermia treatments and the magnitude of the third harmonic of the frequency spectrum of the magnetization, which plays a central role in magnetic particle imaging.

Multicore iron oxide nanoparticles for magnetic hyperthermia and combination therapy against cancer cells

HypothesisMulticore flower-like iron oxide nanoparticles (IONPs) are among the best candidates for magnetic hyperthermia applications against cancers. However, they are rarely investigated in physiological environments and their efficacy against cancer cells has been even less studied. The combination of magnetic hyperthermia, using multicore IONPs, with selected bioactive molecules should lead to an enhanced activity against cancer cells. ExperimentsMulticore IONPs were synthesized by a seeded-growth thermal decomposition approach. Then, the cytotoxicity, cell uptake, and efficacy of the magnetic hyperthermia approach were studied with six cancer cell lines: PANC1 (pancreatic carcinoma), Mel202 (uveal melanoma), MCF7 (breast adenocarcinoma), MB231 (triple-negative breast cancer line), A549 (lung cancer), and HCT116 (colon cancer). Finally, IONPs were modified with a chemotherapeutic drug (SN38) and tumor suppressor microRNAs (miR-34a, miR-182, let-7b, and miR-137), to study their activity against cancer cells with and without combination with magnetic hyperthermia. FindingsTwo types of multicore IONPs with very good heating abilities under magnetic stimulation have been prepared. Their concentration-dependent cytotoxicity and internalization have been established, showing a strong dependence on the cell line and the nanoparticle type. Magnetic hyperthermia causes significant cell death that is dramatically enhanced in combination with the bioactive molecules.

Nanoarchitectonic Engineering of Thermal-Responsive Magnetic Nanorobot Collectives for Intracranial Aneurysm Therapy.

Stent-assisted coiling is a main treatment modality for intracranial aneurysms (IAs) in clinics, but critical challenges remain to be overcome, such as exogenous implant-induced stenosis and reliance on antiplatelet agents. Herein, an endovascular approach is reported for IA therapy without stent grafting or microcatheter shaping, enabled by active delivery of thrombin (Th) to target aneurysms using innovative phase-change material (PCM)-coated magnetite-thrombin (Fe3O4-Th@PCM) FTP nanorobots. The nanorobots are controlled by an integrated actuation system of dynamic torque-force hybrid magnetic fields. With robust intravascular navigation guided by real-time ultrasound imaging, nanorobotic collectives can effectively accumulate and retain in model aneurysms constructed in vivo, followed by controlled release of the encapsulated Th for rapid occlusion of the aneurysm upon melting the protective PCM (thermally responsive in a tunable manner) through focused magnetic hyperthermia. Complete and stable aneurysm embolization is confirmed by postoperative examination and 2-week postembolization follow-up using digital subtraction angiography (DSA), contrast-enhanced ultrasound (CEUS), and histological analysis. The safety of the embolization therapy is assessed through biocompatibility evaluation and histopathology assays. This strategy, seamlessly integrating secure drug packaging, agile magnetic actuation, and clinical interventional imaging, avoids possible exogenous implant rejection, circumvents cumbersome microcatheter shaping, and offers a promising option for IA therapy.

Effect of moringa oleifera with pure and Zn-doped Mn and Ni nanoferrites for hyperthermia applications

Nanoferrites like spinel manganese ferrite (MnFe2O4) and inverse spinel nickel ferrite (NiFe2O4) have an efficient heating deportment to the destruction of neoplasm. The incorporation of Moringa oleifera (MO) leaf extracts with magnetic nanoparticles as heat mediators is an effective approach for treating magnetic hyperthermia. This study investigated the potential heating behavior of bare, Zn-doped MnFe2O4 and NiFe2O4 nanoparticles (NPs) with Moringa oleifera leaf extracts as magnetic hyperthermia agents. High-resolution transmission electron microscopy showed the spherical-like morphology of MnFe2O4 NPs with no impurities in the EDX spectra. X-ray diffraction spectra confirmed the cubic spinel and inverse spinel structure for MnFe2O4 and NiFe2O4 NPs, respectively. Magnetic properties of the prepared nanoferrites exhibit low coercivity values (in the range of 13–18 Oe representing superparamagnetic behavior. Further, the binding energies of the prepared nanoferrites were revealed by X-ray photoelectron spectroscopy. The effective magnetic anisotropy constant (Keff) was calculated to be around 3.9–5.9 kJ/m3 by electron spin resonance. An increased specific surface area (120.69 m2/g) and wider porosity (17.053 nm) were observed for MnFe2O4/MO NPs through Brunauer-Emmett-Teller (BET) analysis. Thermal properties were investigated by measuring the effective specific absorption rate in an alternating magnetic field ranging from 23 to 31 * 10−9 W/g Oe2 Hz. Results indicated that the green synthesized MnFe2O4/MO NPs are promising agents for magnetic hyperthermia applications in cancer therapy.

Influence of preparation method on structural, optical and magnetic properties of synthesized Zn0.5Mg0.5−xNixFe2O4 nano-ferrite

Structural, optical, and magnetic properties of ferrite series with chemical formula Zn0.5NixMg0.5−xFe2O4 (x = 0.0, 0.1, 0.2, 0.3 and 0.4) were investigated. Co-precipitation and sol–gel methods were used to synthesis the samples and to investigate further the influence of these preparation methods on the properties of Zn0.5NixMg0.5−xFe2O4 nano-ferrites. X-ray diffraction and Fourier-transform infrared spectroscopy revealed that the samples crystallize in a cubic spinel structure with space group Fd3m:1. The crystallite size of Zn0.5NixMg0.5−xFe2O4 nanoparticles was decreased from 19.15 to 11.65 nm with increasing Ni content for the samples of co-precipitation method, while the opposite behavior was observed in case of sol–gel method which was increased from 13.90 to 21.90 nm. Moreover, the optical investigation by UV-visible spectroscopy revealed that the energy band gap of the samples of co-precipitation method ranged (6.04–6.08) eV compared to (4.44–4.50) eV of sol–gel method. For both methods, substitution of Ni+2 by Mg+2 in Zn0.5NixMg0.5−xFe2O4 affects the remanent magnetization (Mr), coercivity (Hc) and saturation magnetization (Ms) suggesting the super-paramagnetic behavior of the samples. The substitution of Ni resulted in small values of coercivity ranged 0.758 to 164.62 Oe. The Ms was ranged 20.39 to 127.57 emu g−1 and an enhancement in magnetization was observed which increases the value of Ms that was found to be maximum with x = 0.4 of co-precipitation method (127.57 emu g−1). The magnetic behavior of synthesized Ni doped nanoparticles makes them suitable candidate for sensing and high-frequency applications and for use in hyperthermia treatment. The characterization outcomes may recommend that co-precipitation method is preferred over sol–gel method for refined structure and preferable properties of Zn0.5NixMg0.5−xFe2O4 nanoparticles.

The Role of Nanomedicine in Benign Gynecologic Disorders.

Nanomedicine has revolutionized drug delivery in the last two decades. Nanoparticles appear to be a promising drug delivery platform in the treatment of various gynecological disorders including uterine leiomyoma, endometriosis, polycystic ovarian syndrome (PCOS), and menopause. Nanoparticles are tiny (mean size < 1000 nm), biodegradable, biocompatible, non-toxic, safe, and relatively inexpensive materials commonly used in imaging and the drug delivery of various therapeutics, such as chemotherapeutics, small molecule inhibitors, immune mediators, protein peptides and non-coding RNA. We performed a literature review of published studies to examine the role of nanoparticles in treating uterine leiomyoma, endometriosis, PCOS, and menopause. In uterine leiomyoma, nanoparticles containing 2-methoxyestradiole and simvastatin, promising uterine fibroid treatments, have been effective in significantly inhibiting tumor growth compared to controls in in vivo mouse models with patient-derived leiomyoma xenografts. Nanoparticles have also shown efficacy in delivering magnetic hyperthermia to ablate endometriotic tissue. Moreover, nanoparticles can be used to deliver hormones and have shown efficacy as a mechanism for transdermal hormone replacement therapy in individuals with menopause. In this review, we aim to summarize research findings and report the efficacy of nanoparticles and nanotherapeutics in the treatment of various benign gynecologic conditions.

Synthesis, Surface Modification and Magnetic Properties Analysis of Heat-Generating Cobalt-Substituted Magnetite Nanoparticles.

Here, we present the results of the synthesis, surface modification, and properties analysis of magnetite-based nanoparticles, specifically Co0.047Fe2.953O4 (S1) and Co0.086Fe2.914O4 (S2). These nanoparticles were synthesized using the co-precipitation method at 80 °C for 2 h. They exhibit a single-phase nature and crystallize in a spinel-type structure (space group Fd3¯m). Transmission electron microscopy analysis reveals that the particles are quasi-spherical in shape and approximately 11 nm in size. An observed increase in saturation magnetization, coercivity, remanence, and blocking temperature in S2 compared to S1 can be attributed to an increase in magnetocrystalline anisotropy due to the incorporation of Co ions in the crystal lattice of the parent compound (Fe3O4). The heating efficiency of the samples was determined by fitting the Box-Lucas equation to the acquired temperature curves. The calculated Specific Loss Power (SLP) values were 46 W/g and 23 W/g (under HAC = 200 Oe and f = 252 kHz) for S1 and S2, respectively. Additionally, sample S1 was coated with citric acid (Co0.047Fe2.953O4@CA) and poly(acrylic acid) (Co0.047Fe2.953O4@PAA) to obtain stable colloids for further tests for magnetic hyperthermia applications in cancer therapy. Fits of the Box-Lucas equation provided SLP values of 21 W/g and 34 W/g for CA- and PAA-coated samples, respectively. On the other hand, X-ray photoelectron spectroscopy analysis points to the catalytically active centers Fe2+/Fe3+ and Co2+/Co3+ on the particle surface, suggesting possible applications of the samples as heterogeneous self-heating catalysts in advanced oxidation processes under an AC magnetic field.

Study of biopolymer encapsulated Eu doped Fe3O4 nanoparticles for magnetic hyperthermia application

An exciting prospect in the field of magnetic fluid hyperthermia (MFH) has been the integration of noble rare earth elements (Eu) with biopolymers (chitosan/dextran) that have optimum structures to tune specific effects on magnetic nanoparticles (NPs). However, the heating efficiency of MNPs is primarily influenced by their magnetization, size distribution, magnetic anisotropy, dipolar interaction, amplitude, and frequency of the applied field, the MNPs with high heating efficiency are still challenging. In this study, a comprehensive experimental analysis has been conducted on single-domain magnetic nanoparticles (SDMNPs) for evaluating effective anisotropy, assessing the impact of particle-intrinsic factors and experimental conditions on self-heating efficiency in both noninteracting and interacting systems, with a particular focus on the dipolar interaction effect. The study successfully reconciles conflicting findings on the interaction effects in the agglomeration and less agglomerated arrangements for MFH applications. The results suggest that effective control of dipolar interactions can be achieved by encapsulating Chitosan/Dextran in the synthesized MNPs. The lower dipolar interactions successfully tune the self-heating efficiency and hold promise as potential candidates for MFH applications.

Synthesis, physico-chemical properties, and AC induction heating of polycaprolactone-coated bio-compatible Fe3O4 nanoparticles

Ex-situ functionalization of Fe3O4 nanoparticles, synthesized using a coprecipitation method, with bio-compatible polycaprolactone (PCL) polymer is reported in this study. The formation of the crystalline structure of Fe3O4 is confirmed from the X-ray diffraction patterns. The presence of the PCL polymer on the surface of the coated MNPs is confirmed using Fourier transform infrared and X-ray photoelectron spectroscopy techniques and thermogravimetric analysis. Scanning and transmission electron microscopy imaging studies reveal the nearly spherical morphology of the synthesized nanoparticles. Room temperature magnetization measurements show the superparamagnetic nature of the PCL coated nanoparticles with high saturation magnetizations varying from ∼61–66 emu/g. Further, the room temperature coercivity is found to be reduced by ∼78 % for the PCL coated nanoparticles, which is attributed to the lowering of the interparticle interactions upon surface functionalization. Magnetic fluid hyperthermia studies on the PCL coated nanoparticles dispersed in ∼1 wt% agar gel shows significant alternating magnetic field induced heating efficiency, with temperature rise in the vicinity of the hyperthermia limit (∼42 °C). The highest specific absorption rate is found to be ∼85.4 ± 3.9 W/gFe, indicating an intrinsic loss power of ∼0.62 nHm2kg−1, which is significantly higher than the previously reported values for PCL coated Fe3O4 MNPs. The field induced heating efficiency is found to be correlated with the saturation magnetization of the PCL coated nanoparticles. In vitro cytotoxicity studies on human breast cancer (MCF-7) cell lines confirm the superior bio-compatibility of the PCL coated Fe3O4 nanoparticles. Superior field induced heating efficiency, coupled with good bio-compatibility makes the PCL functionalized Fe3O4 nanoparticles a potential candidate for magnetic fluid hyperthermia.

Curie temperature and magnetic permeability regulation of Cr–Mg co-doped NiCuZn ferrite for tumor hyperthermia

The controllable Curie temperature and high magnetic permeability of NiCuZn ferrites make them promising candidates for magnetic thermal medium. However, the temperature control of existing NiCuZn ferrite materials is not accurate enough to achieve the low Curie temperature required for tumor hyperthermia. In order to further achieve the desired Curie temperature and facilitate the advancement of temperature control materials for tumor hyperthermia, Cr–Mg co-doped NiCuZn ferrite was studied. The study investigated the influence of varying concentrations of Cr3+ on the crystal structure and magnetic properties of Mg–NiCuZn ferrites. The results of structural characterization demonstrate that Cr–Mg co-doped NiCuZn ferrites exhibit high density and uniform distribution of elements. The introduction of Cr3+ leads to a reduction in lattice parameters and a preference for octahedral B-sites. The hysteresis loop results show that the saturation magnetization first increases and then decreases with the increase of Cr3+ concentration. Ni0.09Mg0.20Cu0.14Zn0.60Fe1.89Cr0.050O3.94 ferrite at 0.30 wt% of Bi2O3 exhibits optimal magnetic characteristics, including a saturation magnetization of ∼36.7 emu/g, low coercivity of ∼0.07 kA/m, high permeability of ∼982.43 @1 MHz, and an appropriate Curie temperature of 45.59 °C. Such permeability and Curie temperature can be used in the body cavity perfusion hyperthermia and deep thermal therapy.

Combined mild magnetic hyperthermia and calcium ion regulation for enhanced immunotherapy of orthotopic liver cancer

Cancer immunotherapy relies on immune cells activation to fight malignancies. Liver serves as the important organs with abundant immune cells. However, in the process of liver tumor development, immune cells lose original function of fighting tumors affected by tumor immunosuppressive microenvironment. Here, a hyaluronic acid-modified calcium phosphate-coated magnetic nanoparticles (named as MSCH) is used to remodel immunosuppressive microenvironment of liver tumors to multiple activate immune cells based on mild magnetic hyperthermia therapy (MHT) and calcium ions regulation strategy. In detail, intra-tumoral acidic microenvironment and mild MHT effectively promote calcium ions release from MSCH to activate casepase-1, resulting in tumor-associated macrophages (TAMs) M1 polarization. Meanwhile, mild MHT significantly upregulate RAE-1ɛ proteins expression in liver cancer cells, ligands for natural killer group 2 member D (NKG2D), resulting in natural killer (NK) cell activation. Moreover, the synergistic effect of mild MHT and calcium overload in cancer cells enables tumor immunogenic cell death (ICD) to activate robust adaptive immune responses. Most importantly, the mild MHT featuring excellent deep tissue penetration ensures the heat accumulation in liver tumors. The multi-activated immune cells therapy strategy based on mild MHT and calcium ions regulation has demonstrated excellent therapeutic effects for orthotopic liver cancer tumor.

Superparamagnetic iron oxide nanoparticles functionalized by biocompatible ligands with enhanced high specific absorption rate for magnetic hyperthermia

This study introduces a novel green nanocomposite system of iron oxide coated with secondary metabolites (Fe3O4@SM) and compares it with commonly used materials for hyperthermia cancer treatment. Fe3O4@SM magnetic nanoparticles were synthesized through a simple co-precipitation process using metal precursors, followed by heating in pressure reactor to obtain superparamagnetic nanoparticles (Hc = 36.5–54.1 Oe at 300 K). These nanoparticles were subsequently coated with plant-based phytochemicals. XRD analysis confirmed the presence of magnetite iron oxide nanoparticles. SEM images further confirmed the spherical shape of the synthesized nanoparticles, exhibiting a face-centered cubic (FCC) iron oxide structure with sizes ranging from 12±7–85±15 nm. Characterization through dynamic light scattering (DLS) and zeta potential (ζ) analysis demonstrated colloidal stability, with a polydispersity index (PDI) ranging from 0.226 to 0.436 and zeta potential values ranging from −29.761–1.85 mV. The surface of the nanoparticles was analyzed using GC-MS, which identified bioactive functional groups including ester (42.79 %), terpene (20.69 %), hydrocarbons (17.4 %), and carboxylic (12.37 %) compounds. Compared to Fe3O4 and Fe3O4@GO, Fe3O4@SM exhibited a higher rate of temperature increase within the therapeutic range, reaching Tmax = 45°C with a heating rate (dT/dt) of 0.273 °C/s and specific absorption rate (SAR) of 230.6 W/g at 304 kHz and 400 Oe. In vitro assays utilizing a triple negative breast cancer microenvironment confirmed the non-toxicity of these materials through a DNS assay. The developed nanoparticles offer dual mechanisms of action, combining thermal and chemo effects, making them promising candidates for hyperthermia cancer treatment.

Ca2+ Overload Decreased Cellular Viability in Magnetic Hyperthermia without a Macroscopic Temperature Rise.

Magnetic hyperthermia is a crucial medical engineering technique for treating diseases, which usually uses alternating magnetic fields (AMF) to interplay with magnetic substances to generate heat. Recently, it has been found that in some cases, there is no detectable temperature increment after applying an AMF, which caused corresponding effects surprisingly. The mechanisms involved in this phenomenon are not yet fully understood. In this study, we aimed to explore the role of Ca2+ overload in the magnetic hyperthermia effect without a perceptible temperature rise. A cellular system expressing the fusion proteins TRPV1 and ferritin was prepared. The application of an AMF (518 kHz, 16 kA/m) could induce the fusion protein to release a large amount of iron ions, which then participates in the production of massive reactive oxygen radicals (ROS). Both ROS and its induced lipid oxidation enticed the opening of ion channels, causing intracellular Ca2+ overload, which further led to decreased cellular viability. Taken together, Ca2+ overload triggered by elevated ROS and the induced oxidation of lipids contributes to the magnetic hyperthermia effect without a perceptible temperature rise. These findings would be beneficial for expanding the application of temperature-free magnetic hyperthermia, such as in cellular and neural regulation, design of new cancer treatment methods.

Recent Developments in Magnetic Hyperthermia Therapy (MHT) and Magnetic Particle Imaging (MPI) in the Brain Tumor Field: A Scoping Review and Meta-Analysis.

Magnetic hyperthermia therapy (MHT) is a promising treatment modality for brain tumors using magnetic nanoparticles (MNPs) locally delivered to the tumor and activated with an external alternating magnetic field (AMF) to generate antitumor effects through localized heating. Magnetic particle imaging (MPI) is an emerging technology offering strong signal-to-noise for nanoparticle localization. A scoping review was performed by systematically querying Pubmed, Scopus, and Embase. In total, 251 articles were returned, 12 included. Articles were analyzed for nanoparticle type used, MHT parameters, and MPI applications. Preliminary results show that MHT is an exciting treatment modality with unique advantages over current heat-based therapies for brain cancer. Effective application relies on the further development of unique magnetic nanoparticle constructs and imaging modalities, such as MPI, that can enable real-time MNP imaging for improved therapeutic outcomes.

ESHO 1–85. Hyperthermia as an adjuvant to radiation therapy in the treatment of locally advanced breast carcinoma. A randomized multicenter study by the European Society for Hyperthermic Oncology

BackgroundThe ESHO protocol 1–85 is a multicenter randomized trial initiated by the European Society for Hyperthermic Oncology with the aim to investigate the value of hyperthermia (HT) as an adjuvant to radiotherapy (RT) in treatment of locally advanced breast carcinoma. The trial is one of the largest studies of hyperthermia in radiotherapy but has not been previously published. Patients and methodsBetween February 1987 and November 1993, 155 tumors in 151 patients were included. Tumors were stratified according to institution and size (T2-3/T4) and randomly assigned to receive radiotherapy alone (2 Gy/fx, 5 fx/wk) to a total dose of 65–70 Gy, incl. boost, or the same radiotherapy followed once weekly by hyperthermia (aimed for 43 °C for 60 min). Radiation was given with high voltage photons or electrons. The primary endpoint was persistent complete response (local control) in the treated area. ResultsA total of 146 tumors in 142 patients were evaluable, with a median observation time of 19 (range 1–134) months. Seventy tumors were randomized to RT alone and 76 to RT + HT. Size was T4 in 92, and T2-3 in 54 tumors, respectively. The compliance to RT was good with all but 4 patients fulfilling the planned RT treatment. The tolerance to HT was fair, but associated with moderate to severe pain and discomfort in 15 % of the treatments. In 84 % of the heated patients a least one heat treatment achieved the target temperature, but the temperature variation was large. Addition of heat did not significantly increase the acute nor late radiation reactions.Overall, the 5-year actuarial local failure rate was 57 %. Univariate analysis showed a significant influence of hyperthermia (RT alone 68 % versus RT + HT 50 %, p = 0.04, and T-size (T4 75 % versus T2-3 36 %, p < 0.01). A Cox multivariate analysis showed the same factors to be the only significant prognostic parameters: hyperthermia (HR: 0.61 [0.38–0.98], and small tumor strata (HR: 0.46 [0.26–0.92]. Consequentially, more patients given RT + HT (36 %) survived without disease (DFS), than after RT alone (19 %), p = 0.021) ConclusionA randomized multicenter trial investigating the addition of a weekly hyperthermia treatment to radiotherapy of patients with locally advanced breast cancer significantly enhanced the 5-year tumor control and yielded more patients surviving free from cancer. The results substantiate the potential clinical benefit of hyperthermic oncology.