Magnetic Hyperthermia Treatment Research Articles

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.

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.

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.

Magnetite nanoparticles: an emerging adjunctive tool for the improvement of cancer immunotherapy.

Cancer immunotherapy has emerged as a groundbreaking field, offering promising and transformative tools for oncological research and treatment. However, it faces several limitations, including variations in cancer types, dependence on the tumor microenvironments (TMEs), immune cell exhaustion, and adverse reactions. Magnetic nanoparticles, particularly magnetite nanoparticles (MNPs), with established pharmacodynamics and pharmacokinetics for clinical use, hold great promise in this context and are now being explored for therapeutic aims. Numerous preclinical studies have illustrated their efficacy in enhancing immunotherapy through various strategies, such as modulating leukocyte functions, creating favorable TMEs for cytotoxic T lymphocytes, combining with monoclonal antibodies, and stimulating the immune response via magnetic hyperthermia (MHT) treatment (Front Immunol. 2021;12:701485. doi: 10.3389/fimmu.2021.701485). However, the current clinical trials of MNPs are mostly for diagnostic aims and as a tool for generating hyperthermia for tumor ablation. With concerns about the adverse effects of MNPs in the in vivo systems, clinical translation and clinical study of MNP-boosted immunotherapy remains limited. The lack of extensive clinical investigations poses a current barrier to patient application. Urgent efforts are needed to ascertain both the efficacy of MNP-enhanced immunotherapy and its safety profile in combination therapy. This article reviews the roles, potential, and challenges of using MNPs in advancing cancer immunotherapy. The application of MNPs in boosting immunotherapy, and its perspective role in research and development is also discussed.

Concentration dependent thermal properties of magnetic nanoparticles and ability to use in the magnetic hyperthermia treatment

Concentration dependent thermal properties of magnetic nanoparticles and ability to use in the magnetic hyperthermia treatment

A magnetic cross-linked alginate-biobased nanocomposite with anticancer and hyperthermia activities

This research study focuses on a new magnetic nanobiocomposite designed and synthesized by the formation of cross-linked alginate (Alg) hydrogel using CaCl2 cross-linker agent, its modification with flaxseed mucilage hydrogel and silk fibroin (SF) biopolymer extracted, and as well, the in-situ synthesis of Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) in the presence of this biopolymeric substrate. FT-IR, EDX, FE-SEM, XRD, VSM, and TG technical analyses clarified the physical and chemical features of magnetic cross-linked Alg/flaxseed mucilage hydrogel/SF nanobiocomposite. Following the structural characterization of this magnetic natural-based composition, the in-vitro cytotoxicity and hemolysis assay studies with different concentrations resulted in prominent biological outcomes. The survival rates of normal HEK293T cells (95.74%, 94.18%) and breast cancer BT549 cells (79.23%, 77.76%) after 48 and 72 h verified the biocompatibility and anticancer properties of this new nanobiocomposite. Also, less than 5% of the hemolytic effect disclosed its hemocompatibility. Furthermore, a high specific absorption rate value (72.42 W/g) is generated by 1 mg/mL of this magnetic nanobiocomposite. Overall, it can be deduced that magnetic responsive cross-linked Alg/flaxseed mucilage hydrogel/SF nanobiocomposite could functionally perform in magnetic hyperthermia treatment.

Synthesis of Mesoporous Core Shell Magnetite Bioactive Glass Nanoparticles for Magnetic Hyperthermia Treatment of Cancer

AbstractMultiple biological advances have made use of bioactive glass (BG) nanoparticles (NPs) in regenerative medicine, bone and tooth repair, drug and gene transfer, cancer treatment, and cosmetics. Normal biocompatible coatings alongside hydrocarbons, polymers, and silica significantly affect fundamental attributes of NPs. In this study, we synthesized a novel mesoporous BG NPs with magnetite core shell (AMAG_BG) using L‐arginine as a template processing magnetic hyperthermia (MH). BG network coverage on magnetite (AMAG) NPs were orchestrated first time by bio‐inspired synthesis in watery dissolvable. AMAG and AMAG_BG NPs were characterized by utilizing FE‐SEM, HR‐TEM, and BET analysis. The elemental composition of L‐arginine templated magnetite (AMAG) and AMAG_BG NPs was also determined by XPS and EDX analysis. Characteristics of AMAG_BG were contrasted with bare AMAG NPs in morphology, particle size, porosity, and composition. The fabricated BG NPs′ in‐vitro bioactivity and heat studies were successfully monitored after interaction with simulated bodily fluid (SBF). Magnetic studies and in‐vitro heat studies together demonstrated the behavior of BG NPs towards MH treatment of cancerous cells. Cytotoxicity tests on AMAG_BG NPs using U2OS and human blood cells with appropriate control experiments revealed biocompatibility. The study represents magnetic and thermal property‐dependent sustainable synthetic process of AMAG BG NPs for cancer treatment.

Heating Capacity and Biocompatibility of Hybrid Nanoparticles for Magnetic Hyperthermia Treatment.

Cancer is one of the deadliest diseases worldwide and has been responsible for millions of deaths. However, developing a satisfactory smart multifunctional material combining different strategies to kill cancer cells poses a challenge. This work aims at filling this gap by developing a composite material for cancer treatment through hyperthermia and drug release. With this purpose, magnetic nanoparticles were coated with a polymer matrix consisting of poly (L-co-D,L lactic acid-co-trimethylene carbonate) and a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer. High-resolution transmission electron microscopy and selected area electron diffraction confirmed magnetite to be the only iron oxide in the sample. Cytotoxicity and heat release assays on the hybrid nanoparticles were performed here for the first time. The heat induction results indicate that these new magnetic hybrid nanoparticles are capable of increasing the temperature by more than 5 °C, the minimal temperature rise required for being effectively used in hyperthermia treatments. The biocompatibility assays conducted under different concentrations, in the presence and in the absence of an external alternating current magnetic field, did not reveal any cytotoxicity. Therefore, the overall results indicate that the investigated hybrid nanoparticles have a great potential to be used as carrier systems for cancer treatment by hyperthermia.

Design and fabrication of a magnetic nanobiocomposite based on flaxseed mucilage hydrogel and silk fibroin for biomedical and in-vitro hyperthermia applications

In this research work, a magnetic nanobiocomposite is designed and presented based on the extraction of flaxseed mucilage hydrogel, silk fibroin (SF), and Fe3O4 magnetic nanoparticles (Fe3O4 MNPs). The physiochemical features of magnetic flaxseed mucilage hydrogel/SF nanobiocomposite are evaluated by FT-IR, EDX, FE-SEM, TEM, XRD, VSM, and TG technical analyses. In addition to chemical characterization, given its natural-based composition, the in-vitro cytotoxicity and hemolysis assays are studied and the results are considerable. Following the use of highest concentration of magnetic flaxseed mucilage hydrogel/SF nanobiocomposite (1.75 mg/mL) and the cell viability percentage of two different cell lines including normal HEK293T cells (95.73%, 96.19%) and breast cancer BT549 cells (87.32%, 86.9%) in 2 and 3 days, it can be inferred that this magnetic nanobiocomposite is biocompatible with HEK293T cells and can inhibit the growth of BT549 cell lines. Besides, observing less than 5% of hemolytic effect can confirm its hemocompatibility. Furthermore, the high specific absorption rate value (107.8 W/g) at 200 kHz is generated by a determined concentration of this nanobiocomposite (1 mg/mL). According to these biological assays, this magnetic responsive cytocompatible composite can be contemplated as a high-potent substrate for further biomedical applications like magnetic hyperthermia treatment and tissue engineering.

The effects of fractional time derivatives in bioheat conduction technique on tumor thermal therapy

Abstract The article utilizes the fractional bioheat model in spherical coordinates to explain the transfer of heat in living tissues during magnetic hyperthermia treatment for tumors. Maintaining therapeutic temperature is crucial in magnetic fluid hyperthermia, which requires accurate estimations of power dissipation to determine the appropriate number of magnetic particles required for treatment. To address this problem, a hybrid numerical approach that combines Laplace transforms, change of variables, and modified discretization techniques is proposed in this paper. The study investigates the impact of the fractional parameter and differences in thermophysical properties between diseased and healthy tissue. The numerical temperature results are presented in a graph, and their validity is demonstrated by comparing them with previous literature.

Evaluation of Magnetic Hyperthermia Efficiency of PEG-Coated Fe3O4 Nanoparticles

Magnetic nanoparticle hyperthermia has drawn considerable interest in cancer therapy. In this study, we report the synthesis of PEG-coated Fe3O4 nanoparticles and evaluate their suitability for magnetic hyperthermia applications. Fe3O4 nanoparticles were synthesized by the chemical coprecipitation method, which are coated with polyethylene glycol (PEG). PEG-coated Fe3O4 nanoparticles were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), dynamic light scattering (DLS) and transmission electron microscopy (TEM). Synthesized nanoparticles possess inverse-spinel structural with a crystallite size of 9.1[Formula: see text]nm. From the M-H hysteresis loops, it was confirmed that the synthesized Fe3O4 nanoparticles were superparamagnetic. The physical size of bare Fe3O4 nanoparticles, as determined from the HR-TEM, is [Formula: see text][Formula: see text]nm, and the corresponding hydrodynamic size of PEG-coated Fe3O4 nanoparticles is [Formula: see text][Formula: see text]nm. Magnetic hyperthermia efficiency of PEG-coated Fe3O4 nanoparticles was determined as a function of magnetic field frequency (162–935.6[Formula: see text]kHz), field strength (5–12[Formula: see text]mT) and nanoparticle concentration (1–100[Formula: see text]mg/mL). Temperature rise in an aqueous dispersion of PEG-coated Fe3O4 nanoparticles was measured for 20[Formula: see text]min. The specific loss power (SLP) was calculated by the corrected slope method. SLP values of PEG-coated Fe3O4 nanoparticles increase with magnetic field frequency and field strength and decrease with nanoparticle concentration. The optimum hyperthermia performance of PEG-coated Fe3O4 nanoparticles was observed for 935.6[Formula: see text]kHz frequency, 10[Formula: see text]mT field strength and 25[Formula: see text]mg/mL concentration. Under these conditions, the measured SLP of PEG-coated Fe3O4 nanoparticles was 4.43[Formula: see text]W/g. These results show that the synthesized PEG-coated Fe3O4 nanoparticles could be a potential candidate for magnetic hyperthermia treatment of cancer.

Improving the Efficacy of Magnetic Nanoparticle-Mediated Hyperthermia Using Trapezoidal Pulsed Electromagnetic Fields as an In Vitro Anticancer Treatment in Melanoma and Glioblastoma Multiforme Cell Lines.

Magnetic hyperthermia (MHT) is an oncological therapy that uses magnetic nanoparticles (MNPs) to generate localized heat under a low-frequency alternating magnetic field (AMF). Recently, trapezoidal pulsed alternating magnetic fields (TPAMFs) have proven their efficacy in enhancing the efficiency of heating in MHT as compared to the sinusoidal one. Our study aims to compare the TPAMF waveform's killing effect against the sinusoidal waveform in B16F10 and CT2A cell lines to determine more efficient waveforms in causing cell death. For that purpose, we used MNPs and different AMF waveforms: trapezoidal (TP), almost-square (TS), triangular (TR), and sinusoidal signal (SN). MNPs at 1 and 4 mg/mL did not affect cell viability during treatment. The exposition of B16F10 and CT2A cells to only AMF showed nonsignificant mortality. Hence, the synergetic effect of the AMF and MNPs causes the observed cell death. Among the explored cases, the nonharmonic signals demonstrated better efficacy than the SN one as an MHT treatment. This study has revealed that the application of TP, TS, or TR waveforms is more efficient and has considerable capability to increase cancer cell death compared to the traditional sinusoidal treatment. Overall, we can conclude that the application of nonharmonic signals enhances MHT treatment efficiency against tumor cells.

Study of the calorimetric effect in ferrogels subjected to the high-frequency rotating magnetic field

This study investigates the calorimetric effect in iron oxide-containing ferrogels when exposed to a high-frequency rotating magnetic field. The primary heat generation mechanisms were magnetic relaxation (Néel and Brownian) and magnetic hysteresis. Temperature was monitored over time for various magnetic field amplitudes, enabling the determination of the contributions of both heat release mechanisms as a function of particle concentration and field strength. Experiments were performed using agar-based tissue mimicking phantoms with magnetic nanoparticle weight concentrations ranging from 5 % to 20 %. The magnetic fields applied varied from 1 kA/m to 5 kA/m, with the equipment having a capability of up to 7.5 kA/m at a frequency of 200 kHz. The experimental setup employed a two-phase magnetic system enclosed in an external core where magnetizing coils and parallel connected inductors and capacitors generated spatially and phase shifted fluxes by 90 degrees, resulting in a constant amplitude of rotating magnetic field.The heating efficiency of the rotating magnetic field was found to be approximately twice as effective as an equivalent alternating field in the experiments. The specific loss power exhibited a decreasing trend with the increase in magnetic nanoparticle concentration and the decrease in magnetic field strength. Specifically, as the magnetic nanoparticle concentration increased from 5 % to 20 %, the SLP diminished from 457.3 mW/g (at 5 % concentration and 5 kA/m) to 1.24 mW/g (at 20 % concentration and 1 kA/m). This decrease in SLP can be attributed to enhanced dipole–dipole interactions between particles at smaller interparticle distances as concentration increases, as well as reduced magnetic responsiveness to weaker magnetic fields. Even though Brownian relaxation was likely hindered in the gel structure due to the immobilization of magnetic nanoparticles, the observed magnetic heating effect remains significant. Given the limited existing data on rotating magnetic field effects on tissue mimicking ferrogels, this study offers novel insights, potentially aiding in the optimization of magnetic hyperthermia treatments while highlighting the benefits of rotating over alternating magnetic fields.

Biodistribution and histological analysis of iron oxide-dextran nanoparticles in wistar rats

Iron oxide nanoparticles (IONP) are showing promise in many biomedical applications. One of these- magnetic hyperthermia- utilizes externally applied alternating magnetic fields and tumor-residing magnetic nanoparticles to generate localized therapeutic temperature elevations. Magnetic hyperthermia is approved in Europe to treat glioblastoma and is undergoing clinical assessment in the United States to treat prostate cancer. In this study, we performed biodistribution and histological analysis of a new IONP (RCL-01) in Wistar rats. These nanoparticles are currently undergoing clinical assessment in locally advanced pancreatic ductal adenocarcinoma to determine the feasibility of magnetic hyperthermia treatment in this disease. The study presented here aimed to determine the fate of these nanoparticles in vivo and whether this results in organ damage. Wistar rats were injected intravenously with relatively high doses of IONP (30 mgFe/kg, 45 mgFe/kg and 60 mgFe/kg) and compared to a vehicle control to determine the accumulation of iron in organs and whether this resulted in histological changes in these tissues. Dose-dependent increases of iron were observed in the liver, spleen and lungs of IONP-treated animals at 7 days postinjection; however, this did not result in significant histological changes in these tissues. Immunofluorescent imaging determined these nanoparticles are internalized by macrophages in tissue, suggesting they are readily phagocytosed by the reticuloendothelial system for eventual recycling. Notably, no changes in iron or dextran staining were found in the kidneys across all treatment groups, providing evidence for potential renal clearance.

Cobalt ferrite nanoparticle for the elimination of CD133+CD44+ and CD44+CD24−, in breast and skin cancer stem cells, using non-ionizing treatments

BackgroundCancer stem cells (CSCs) are the most challenging issue in cancer treatment, because of their high resistance mechanisms, that can cause tumor recurrence after common cancer treatments such as drug and radiation based therapies, and the insufficient efficiency of common treatments in CSCs removal and the recurrence of tumors after these treatments, it is essential to consider other methods, including non-ionizing treatments likes light-based treatments and magnetic hyperthermia (MHT). Method and materialAfter synthesis, characterization and investigation, the toxicity of novel on A375 and MAD-MB-231 cell lines, magnetic hyperthermia and light-based treatments were applied. MTT assay and flow cytometry was employed to determine cell survival. the influence of combination therapy on CD44 + CD24−and CD133 + CD44+ cell population, Comparison and evaluation of combination treatments was done respectively using Combination Indices (CIs). ResultThe final nanoparticle has a high efficiency in producing hydroxyl radicals and generating heat in MHT. According to CIs, we can conclude that combined using of light-based treatment and MHT in the presence of final synthesized nanoparticle have synergistic effect and a high ability to reduce the population of stem cells in both cell lines compared to single treatments. ConclusionIn this study a novel multi-functional nanoplatform acted well in dual and triple combined treatments, and showed a good performance in the eradication of CSCs, in A375 and MAD-MB-231 cell lines.

Quantifying the Efficacy of Magnetic Nanoparticles for MRI and Hyperthermia Applications via Machine Learning Methods.

Magnetic nanoparticles are a prospective class of materials for use in biomedicine as agents for magnetic resonance imagining (MRI) and hyperthermia treatment. However, synthesis of nanoparticles with high efficacy is resource-intensive experimental work. In turn, the use of machine learning (ML) methods is becoming useful in materials design and serves as a great approach to designing nanomagnets for biomedicine. In this work, for the first time, an ML-based approach is developed for the prediction of main parameters of material efficacy, i.e., specific absorption rate (SAR) for hyperthermia and r1 /r2 relaxivities in MRI, with parameters of nanoparticles as well as experimental conditions as descriptors. For that, a unique database with more than 980 magnetic nanoparticles collected from scientific articles is assembled. Using this data, several tree-based ensemble models are trained to predict SAR, r1 and r2 relaxivity. After hyperparameter optimization, models reach performances of R2 = 0.86, R2 = 0.78, and R2 = 0.75, respectively. Testing the models on samples unseen during the training shows no performance drops. Finally, DiMag, an open access resource created to guide synthesis of novel nanosized magnets for MRI and hyperthermia treatment with machine learning and boost development of new biomedical agents, is developed.

Investigation of Cr3+ doped Zn-Co nanoferrites as potential candidate for self-regulated magnetic hyperthermia applications

Controlling the Curie temperature (TC) in the range from 42 °C–46 °C in magnetic hyperthermia (MH) therapy is an essential research topic because overheating can cause irreversible damage to healthy tissue. When TC is in the above temperature range, the magnetic nanoparticles reach a paramagnetic state, effectively turning off the MH treatment. In this work, we synthesized Zn-Co nanoparticles of representative composition Zn0.54Co0.46CrxFe2-xO4, where the Fe3+ cations are carefully replaced by Cr3+ ions, which allow a precise tuning of TC and hence the self-regulation of MH. The x-ray diffraction analysis of the prepared nanoparticles confirms the formation of a single-phase cubic spinel structure. The average crystallite of the nanoparticles increases with Cr3+ doping, while the Tc and saturation magnetization decrease considerably from 78 °C (x = 0.1) to 27 °C (x = 0.6) and 46.6 emu g−1 (x = 0.1) to 15.3 emu g−1 (x = 0.6), respectively. Besides MH potential of the investigated samples as revealed from specific absorption rate (SAR) assays and the maximum temperature reach (Tmax), vary from 7 W g−1 and 37.3 °C, for x = 0.6, to 38 W g−1 and 62.9 °C, for x = 0.1, we found that the composition Zn0.54Co0.46Cr0.4Fe1.6O4 is more promising with SAR of 22 W g−1 and Tmax = 42.3 °C, which is precisely lies in the safe temperature range to automatically activate the self-regulation during the magnetic hyperthermia treatment. The results reveal an excellent combination between size distribution and Cr3+ content in Zn-Co-based ferrite, which has a great potential for self-regulated magnetic hyperthermia applications.

Production and Characterization of Magnetic‐Luminescent Fe3O4@ZnO:RE Composite Nanoparticles for Biomedical Application

Magnetic‐luminescent composite nanoparticles (Fe3O4@ZnO:RE) with a core/shell structure are produced by a simple process. Magnetite nanoparticles (Fe3O4) are coated with rare‐earth‐doped zinc oxide (ZnO). Core/shell structure is confirmed by high‐resolution transmission electron microscopy (HR‐TEM) analysis. X‐ray diffraction analysis results show that cubic magnetite Fe3O4 and hexagonal ZnO phases originate from the core and the shell, respectively. Hexagonal ZnO and cubic magnetite Fe3O4 phases belonging all nanoparticles are confirmed by HR‐TEM benefiting the lattice fringe. All the nanoparticles present superparamagnetic behavior. Under 532 nm excitation, they release the emission in the visible and infrared regions. They exhibit blue–green emission attributed to 2H11/2–4I15/2, 4S3/2–4I15/2 transitions, red emission attributed to 4F9/2–4I15/2 transitions, and infrared emission ascribed to 4F9/2–4I15/2, 2F7/2–2F5/2 transitions. Above the 0.2mol% dopant ratio, the luminescence intensity starts to decrease because of the concentration quenching. The produced nanoparticles are promising for bioimaging and magnetic hyperthermia treatment, due to their magnetic and luminescent properties, orientation to the target area, and their presence in the target area can be determined.

Investigating Nickel Ferrite (NiFe2O4) Nanoparticles for Magnetic Hyperthermia Applications

Many new promising therapeutic and diagnostic methods in medical science use magnetic nanoparticles (MNPs). Drug targeting, tumor detection, and magnetic hyperthermia treatment are the most common fields of interest where already clinical trials are being performed. Nickel ferrite (NiFe2O4) nanoparticles have received much attention for their potential applications in such fields. A series of samples of Nickel ferrite (NiFe2O4) nanoparticles have been synthesized using a co-precipitation route at different annealing temperatures ranging from 150 ? to 1000 ? and labeling them as S1, S2, S3, S4, and S5. The average particle size obtained from XRD data is found to lie in the range of 15 – 55 nm. The crystal structure of the prepared NiFe2O4 four samples annealed at different temperatures is FCC with a lattice constant of 8.34 Å, which agrees with the values. The magnetic properties of the samples were investigated from temperature-dependent hysteresis loops using Vibrating Sample Magnetometer (VSM). The saturation magnetization (coercivity) is found to increase (decrease) with particle size. The hyperthermia measurements are performed by applying alternating magnetic fields of various amplitudes (Oe) and frequencies (kHz). The measured heating ability of the prepared nanoparticles is obtained from the so-called specific absorption rate (SAR), which is found to increase with increasing frequency and field amplitudes. Using the experimentally obtained SAR value, we also used MATLAB code to model the heat diffusion equation to get information on the temperature rise within the tumor as a function of tumor radius and treatment time.The sample S4 annealed at a temperature of 900 ? is found to be the most suitable candidate for hyperthermia applications at the frequency of 543 kHz because of its capability to produce heat in the therapeutic range of 42-48 ? and with an SAR value of 500 W/g.

Extraction method of nanoparticles concentration distribution from magnetic particle image and its application in thermal damage of magnetic hyperthermia

Magnetic particle imaging (MPI) technology can generate a real-time magnetic nanoparticle (MNP) distribution image for biological tissues, and its use can overcome the limitations imposed in magnetic hyperthermia treatments by the unpredictable MNP distribution after the intratumoral injection of nanofluid. However, the MNP concentration distribution is generally difficult to be extracted from MPI images. This study proposes an approach to extract the corresponding concentration value of each pixel from an MPI image by a least squares method (LSM), which is then translated as MNP concentration distribution by an interpolation function. The resulting MPI-based concentration distribution is used to evaluate the treatment effect and the results are compared with the ones of two baseline cases under the same dose: uniform distribution and MPI-based distribution considering diffusion. Additionally, the treatment effect for all these cases is affected by the blood perfusion rate, which is also investigated deeply in this study. The results demonstrate that the proposed method can be used to effectively reconstruct the concentration distribution from MPI images, and that the weighted LSM considering a quartic polynomial for interpolation provides the best results with respect to other cases considered. Furthermore, the results show that the uniformity of MNP distribution has a positive correlation with both therapeutic temperature distribution and thermal damage degree for the same dose and a critical power dissipation value in the MNPs. The MNPs uniformity inside biological tissue can be improved by the diffusion behavior after the nanofluid injection, which can ultimately reflect as an improvement of treatment effect. In addition, the blood perfusion rate considering local temperature can have a positive effect on the treatment compared to the case which considers a constant value during magnetic hyperthermia.