Hyperthermia Applications Research Articles

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.

Inhibiting AGS Cancer Cell Proliferation through the Combined Application of Aucklandiae Radix and Hyperthermia: Investigating the Roles of Heat Shock Proteins and Reactive Oxygen Species.

Cancer is a major global health concern. To address this, the combination of traditional medicine and newly appreciated therapeutic modalities has been gaining considerable attention. This study explores the combined effects of Aucklandiae Radix (AR) and 43 °C hyperthermia (HT) on human gastric adenocarcinoma (AGS) cell proliferation and apoptosis. We investigated the synergistic effects of AR and HT on cell viability, apoptosis, cell cycle progression, and reactive oxygen species (ROS)-dependent mechanisms. Our findings suggest that the combined treatment led to a notable decrease in AGS cell viability and increased apoptosis. Furthermore, cell cycle arrest at the G2/M phase contributed to the inhibition of cancer cell proliferation. Notably, the roles of heat shock proteins (HSPs) were highlighted, particularly in the context of ROS regulation and the induction of apoptosis. Overexpression of HSPs was observed in cells subjected to HT, whereas their levels were markedly reduced following AR treatment. The suppression of HSPs and the subsequent increase in ROS levels appeared to contribute to the activation of apoptosis, suggesting a potential role for HSPs in the combined therapy's anti-cancer mechanisms. These findings provide valuable insights into the potential of integrating AR and HT in cancer and HSPs.

Chemical and physical modification of graphene oxide nano-sheets using casein, Zn-Al layered double hydroxide, alginate hydrogel, and magnetic nanoparticles for biomedical applications

In our study, we developed a novel nanobiocomposite using graphene oxide (GO), casein (Cas), ZnAl layered double hydroxide (LDH), sodium alginate (Alg), and Fe3O4 magnetic nanoparticles. To synthesize the GO, we used a modified Hummer's method and then covalently functionalized its surface with Cas protein. The functionalized GO was combined with as-synthesized ZnAl LDH, and the composite was conjugated with alginate hydrogel through the gelation process. Finally, we magnetized the nanobiocomposite using in-situ magnetization. The nanobiocomposite was comprehensively characterized using FT-IR, FE-SEM, EDX, and XRD. Its biological potential was assessed through cell viability, hemolysis, and anti-biofilm assays, as well as its application in hyperthermia. The MTT assay showed high cell viability percentages for Hu02 cells after 24, 48, and 72 h of incubation. The nanobiocomposite had a hemolytic effect lower than 3.84 %, and the measured bacterial growth inhibition percentages of E. coli and S. aureus bacteria in the presence of the nanobiocomposite were 52.18 % and 55.72 %, respectively. At a concentration of 1 mg.mL−1 and a frequency of 400 kHz, the nanocomposite exhibits a remarkable specific absorption rate (SAR) of 67.04 W.g−1, showcasing its promising prospects in hyperthermia applications.

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.

Fe3O4/CoFe2O4 core-shell nanoparticles with enhanced magnetic properties for hyperthermia application

Fe3O4/CoFe2O4 core/shell nanoparticles with varying shell thickness were fabricated by seed-mediated growth via thermal decomposition method. Ligand exchange process using poly(maleic anhydride-alt-1-octadecene) (PMAO) was performed to prepare the aqueous magnetic fluids from the as-synthesised nanoparticles. X-ray diffraction (XRD), transmission electron microscopy (TEM) and Quantum Design PPMS VersaLab were utilised to characterise morphological and magnetic properties of the sample. XRD results showed that all the particles were single phase with spinel structure and the average crystallite size in the range of 11–17 nm. All particles were spherical in TEM images with similar size compared to results calculated from XRD. Magnetic measurements were performed at different temperatures (50 − 300 K) at 30 kOe. The result showed that the saturation magnetisation (M s) and coercivity (H C) were significantly increased with the formation of hard magnetic shell with varying thickness. The dynamic light scattering (DLS) analysis presented a narrow distribution and zeta potential of −16 to −35 mV, indicating a good stability of the ferrofluids. The cytotoxicity of the FOC3/PMAO ferrofluid, which has the highest SAR value of 372.02 W g−1, was tested on Hep-G2 cell line at different concentrations from 10 to 100 μg ml−1. Less than 30% of the cell was inhibited, indicating that the FOC3/PMAO particles have low toxicity at these tested concentrations. Thus, these as-synthesised core/shell nanoparticles with uniform particle size, high saturation magnetisation, good stability and five-time increased specific absorption rate (SAR) compared to the Fe3O4 core nanoparticles are very promising in hyperthermia and magnetic resonance imaging (MRI) applications.

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.

Synthesis and characterization of monophasic MnFe2O4 nanoparticles for potential application in magnetic hyperthermia

Nanostructured materials are being used in a wide range of technological applications. In biomedical applications, magnetic hyperthermia (MH) is a therapeutic modality for the treatment of solid tumors. The materials needed for MH face challenges such as size homogeneity, reasonable temperature increase and biocompatibility. In this work, MnFe2O4 magnetic nanoparticles (Nps) were synthesized by a simple method using the bio-polymer chitosan. Samples with several particles sizes were obtained by treatments at the temperatures of 300, 400, 500 and 600 °C. The particle sizes ranged from 7.8 to 13.3 nm. At 300 K, the saturation magnetization of the Nps varied from 16.2 to 35.8 emu/g. The Mössbauer spectra at low temperatures showed the presence of monophasic MnFe2O4. For all samples, the Mössbauer results at 300 K suggest that the samples are in the superparamagnetic regime. The measurements to obtain the Specific Loss Power (SLP) were conducted at a frequency of 74 kHz and AC field amplitude of 247 Oe. The sample thermally treated at 600 °C and the dispersion prepared with a concentration of 1.0 mg/mL showed the highest SLP of 129.1 W/g.

Development of polymeric nanoparticles associated with SPION and curcumin: a versatile magnetic and fluorescent platform for Life Science applications

Magnetic nanoparticles are prominent in biomedical applications due to their adjustable properties through surface functionalization and inherent magnetism. In the present manuscript, multifunctional nanoparticles were synthesized by combining polymer with a fluorophore and magnetic nanoparticles, resulting in a magnetic and fluorescent nanomaterial. A miniemulsion polymerization technique was employed, using the comonomers methyl methacrylate (MMA) and acrylic acid (AA) in the presence of superparamagnetic iron oxide nanoparticles (SPIONs) and natural turmeric extract (curcumin). Physicochemical characterizations revealed efficient encapsulation of SPIONs within the polymer matrices while maintaining superparamagnetic behavior. The nanosystems exhibited ILP values consistent with those commonly used for magnetic hyperthermia applications, ranging from 0.13 – 0.32 nHm2 kg−1. Additionally, a high fluorescence intensity in the blue/green region was observed, alongside no cell toxicity and substantial internalization in human osteosarcoma cells (OSAS2). Given their intrinsic magnetic and fluorescent properties exhibited, the nanosystems can be considered potential candidates for cell tracking and as a platform in nanotheranostics (MRI, magnetic hyperthermia, and photodynamic therapy).

Magnetic membranes based on PVA-SPION for hyperthermia and dielectric applications

Magnetodielectric membranes were spun by electrospinning ferrofluids containing Superparamagnetic Iron Oxide (SPION) in a carrier liquid of Polyvinyl alcohol(PVA) for various loadings of iron oxide. These membranes were characterised using X-ray diffractometer (XRD), Field Emission Scanning Electron Microscopy (FESEM),Vibrational Sample Magnetometry (VSM),Fourier Transform Infrared Spectroscopy (FTIR) and UV–visible spectroscopy (UV–vis) and found to be of good quality having adequate magnetic and dielectric properties. The iron oxide particles were found to be ∼9 nm in size and superparamagnetic in nature. The addition of iron oxide led to a systematic increase in both magnetic and dielectric properties. A maximum saturation magnetization of ∼6.3 emu g−1 and a dielectric constant of ∼50 was obtained for a loading of 40 percentage of Iron oxide. A dielectric transducer was fabricated using the membranes. These membranes also exhibited magnetic hyperthermia as evidenced by magnetic hyperthermia measurements. They are found to be potential candidates for hyperthermia applications as wearables. The method of employing a ferrofluid can be adopted for spinning membranes based on other than PVA/SPION. If the loading is optimised these membranes can be employed as Magnetodielectric transducers.

A novel ternary magnetic nanobiocomposite based on tragacanth-silk fibroin hydrogel for hyperthermia and biological properties.

This study involves the development of a new nanocomposite material for use in biological applications. The nanocomposite was based on tragacanth hydrogel (TG), which was formed through cross-linking of Ca2+ ions with TG polymer chains. The utilization of TG hydrogel and silk fibroin as natural compounds has enhanced the biocompatibility, biodegradability, adhesion, and cell growth properties of the nanobiocomposite. This advancement makes the nanobiocomposite suitable for various biological applications, including drug delivery, wound healing, and tissue engineering. Additionally, Fe3O4 magnetic nanoparticles were synthesized in situ within the nanocomposite to enhance its hyperthermia efficiency. The presence of hydrophilic groups in all components of the nanobiocomposite allowed for good dispersion in water, which is an important factor in increasing the effectiveness of hyperthermia cancer therapy. Hemolysis and 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assays were conducted to evaluate the safety and efficacy of the nanobiocomposite for in-vivo applications. Results showed that even at high concentrations, the nanobiocomposite had minimal hemolytic effects. Finally, the hyperthermia application of the hybrid scaffold was evaluated, with a maximum SAR value of 41.2W/g measured in the first interval.

Radio Frequency (RF) Mediated Hyperthermia of Nickel Ferrites-A Potential Application of Cancer Therapy

We present an invitro study of the hyperthermia application of nanomaterials for the cancer treatment by Radiofrequency (RF). Nickel-ferrite nano materials are synthesized by using microwave hydrothermal method at different pH values under a lower temperature of 160°C for a short holding time of 30 minutes. RF source generator is being used that opeartes at 100 KHz and a temperature regulator monitors the temperature of the solution.The in-vivo experimemnt was conducted with the nanomaterials dispersed in the ferrofluid, and RF energy is appiled when the solution is being placed in a magnetic stirrer. The results shows that the temperature of the nanomaterials has increased beyond 40°C and went up to 45°C with the increase in frequency of the RF under the constant magnetic field of 100 Oe. As the strength of the magnetic field increases the Nanomaterials have shown rapid variation in their temperature Characteristics. The nickel-ferrites have shown linear temperature characteristics under the magnetic field of 100Oe with the RF frequency of 100 KHz. Hence the nickel-ferrites are most suitable for the Hyperthermia application of cancer treatment..The cancerous cells are destroyed by ‘Active cell destruction’ or they are swollen till the cells burst. The superconductivity property of nano particles and Radio Frequency coils used plays the major role in the treatment.

Design and Modelling of an Induction Heating Coil to Investigate the Thermal Response of Magnetic Nanoparticles for Hyperthermia Applications

Magnetic Field Hyperthermia is a technique where tumours are treated through an increase in local temperature upon exposure to alternating magnetic fields (AMFs) that are mediated by magnetic nano-particles (MNPs). In an AMF, these particles heat-up and kill the cells. The relationship between an AMF and the heating-rate is complex, leading to confusion when comparing data for different MNP and AMF conditions. This work allows for the thermal-response to be monitored at multiple AMF amplitudes while keeping other parameters constant. An induction-heating coil was designed based on a Zero-Voltage-Zero-Current (ZVZC) resonant circuit. The coil operates at 93 kHz with a variable DC drive-voltage (12–30 V). NEC4 software was used to model the magnetic field distribution, and MNPs were synthesised by the coprecipitation method. The magnetic field was found to be uniform at the centre of the coil and ranged from 1 kAm−1 to 12 kAm−1, depending on the DC drive-voltage. The MNPs were found to have a specific absorption rate (SAR) of 1.37 Wg−1[Fe] and 6.13 Wg−1[Fe] at 93 kHz and 2.1 kAm−1 and 12.6 kAm−1, respectively. The measured SAR value was found to be directly proportional to the product of the frequency and field-strength (SARα f Ho). This leads to the recommendation that, when comparing data from various groups, the SAR value should be normalized following this relationship and not using the more common relationship based on the square of the field intensity (SARα f Ho2).

Acute Effect of Passive Hyperthermia on Lactate Concentrations

Background: Knowledge on the effect of heat on recovery is still incomplete. The present study aimed to evaluate the effect of a passive acute hyperthermic stimulus before and after a lactic anaerobic test on the production and oxidation of lactate blood concentrations. In addition, the purpose was to evaluate the effect that the application of this previous hyperthermic stimulus may have on the athletic performance in the test. Methods: For this purpose, a cross-over design through an anaerobic treadmill test in three different situations (normothermia, pre-test hyperthermia, and post-test hyperthermia) was performed. Twelve male subjects participated (age: 21.25 ± 1.64 years; height: 1.76 m ± 0.08; weight: 72.59 ± 9.44 kg). An anthropometric assessment was carried out with weight, height, skinfolds, body perimeters and diameters, and external and internal body temperatures in each of the tests. A nutritional survey was also carried out 48 h prior to each test. Results: The results of the study showed a decrease in blood lactate concentrations when the hyperthermic effect was applied as passive recovery just after the end of the test (p < 0.05). A decrease in lactate concentrations was also achieved when applying the hyperthermic effect just before the start of the test (p < 0.05). However, no significant improvements were obtained from this application of heat on test performance. Conclusions: The results suggest that the application of passive acute hyperthermia has a favourable effect in terms of decreasing blood lactate concentrations in a 5 min recovery period after lactic anaerobic activity.

Fabrication of a magnetic nanocomposite based on natural hydrogel: Pectin, tragacanth gum, silk fibroin, and integrated graphitic carbon nitride for hyperthermia and biological features

The current study aimed to design and synthesize a new magnetic nanobiocomposite and assess its potential for biological applications and hyperthermia. For this purpose, in the first step, the Pectin (PC) and Tragacanth gum (TG) polymer was synthesized using CaCl2 as a cross-linking agent (PC-TG hydrogel). In the second step, natural Silk fibroin (SF) protein and graphitic carbon nitride (CN) were added to the hydrogel to upgrade the nanobiocomposite's strength and due to CN's pharmacology applications, respectively. Finally, for an enhanced hyperthermia application, PC-TG hydrogel/SF/CN was in situ magnetized with Fe3O4 magnetic nanoparticles (MNPs), and PC-TG hydrogel/SF/CN/Fe3O4 nanobiocomposite was synthesized. By using a vibrating-sample magnetometer (VSM), Fourier-transformed infrared (FTIR), thermogravimetric analysis (TGA), energy dispersive X-ray (EDX), X-ray diffraction (XRD), and field-emission scanning electron microscope (FESEM), the structural features and properties of the PC-TG hydrogel/SF/CN/Fe3O4 nanobiocomposite were determined. This magnetic nanobiocomposite's saturation magnetization value was 14.84 emu g-1. The hemolytic assay of this new nanobiocomposite demonstrated that the hemolysis percentage was 1.07 %, around 99.0 % of cells were able to survive, and the MTT assay was used to assess the anticancer activity against breast cancer cell lines (BT549). Additionally, 62.51 (W g-1) in 200.0 kHz was found to be the greatest specific absorption rate (SAR). These findings suggest that the recently created magnetic nanobiocomposite might function admirably in hyperthermia treatment when exposed to an alternating magnetic field.

Solvothermally synthesized magnetite nanorods for application in magnetic hyperthermia and photothermia

The development of the multi-functional nanostructures has recently been of particular interest in therapeutic research for various diseases including atherosclerosis, cancer, etc. Indeed, the use of multi-responsive nanostructures that can remotely be activated by different stimuli is a promising strategy to combine the advantages of standalone methods and overcome their intrinsic drawbacks. In this regard, thermal treatment using heat-generating magnetic nanostructures that can remotely respond to a wide range of electromagnetic stimuli is of especial importance, mainly applied through magnetic hyperthermia therapy (MHT) and photothermal therapy (PTT) modalities. In this work, magnetite (Fe3O4) nanorods (MNRs) were synthesized using a one-pot solvothermal process. Adjusting the amount of hexadecylamine capping ligand and the filling percentage of the autoclave, uniformed-sized MNRs of 4·46nm in diameter and 31·09nm in length were prepared and investigated in terms of their heat-generating ability for application in the MHT and PTT. The experimental results show the good heat-generating ability of the MNRs in both modalities with the maximum absorption rate (SAR) values of 228.51 W/g (MHT) and 56.59 W/g (PTT).

Heating ability of amine functionalized Fe3O4 as a function of field amplitude and frequency for hyperthermia application

The functionalization of magnetic nanoparticles (MNPs) is crucial for their biomedical applications such as magnetic hyperthermia, which attracted attention in recent years as a promising alternative or complementary therapy to traditional cancer treatments. Here, we investigate a synthetic approach based on the hydrothermal process for the amine-functionalized magnetite (Fe3O4-NH2) MNPs for possible use in hyperthermia. The characterization of coated MNPs by FTIR confirms the functionalization with the amine group, while the XRD shows how the magnetite phase was formed. Magnetic measurements of both coated and uncoated MNPs at room temperature revealed their ferrimagnetic behavior. It was found from magnetic hyperthermia measurements under an alternating magnetic field (AMF) that functionalized with amine MNPs reach hyperthermia temperatures (42 °C)) in relatively short times (around 10 min.) with a adequate value of sample absorption rate (SAR)in the range between 33 to 45 W g–1. The (NH2) groups on the surface of the (Fe3O4) nanoparticles prepared by hydrothermal process make them amenable to further functionalization with various biomolecules. This enables the nanoparticles to be tailored for specific applications, such as drug delivery or targeting specific cells or tissues. Moreover, the appropriate crystallinity combined with the relatively adequate heating ability and adequate saturation suggest that the functionalized MNPs are promising for hyperthermia application.

Anti-Proliferative Activity of Poloxamer Cobalt Ferrite Nanoparticles against Human Prostate Cancer (DU-145) Cells: In-Vitro Study.

Prostate cancer is the second most frequent type of cancer death in men. This study refers to the novel hyperthermia application of poloxamer-coated cobalt ferrite as a new approach for thermal eradication of DU-145 human prostate cancerous cells under a radio frequency magnetic field (RF-MF). The hydrothermal method was applied for the synthesis of cobalt ferrite nanoparticles. Then, the structure, size, and morphology of nanoparticle were characterized. The cytotoxicity of the synthesized nanoparticles and RF-MF exposure on DU-145 prostate cancer cells was investigated separately or in combination with colony formation methods and MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] assay. Transmission electron microscopy (TEM) confirmed the spherical morphology of nanoparticles with a size of 5.5 ± 2.6 nm. The temperature of cells treated with nanoparticles under RF-MF reached 42.73 ± 0.2°C after 15 min. RF-MF treatment or nanoparticles have not affected cell viability significantly. However, the combination of them eradicated 53% ± 4% of cancerous cells. In-vitro hyperthermia was performed on human prostate cancer cells (DU-145) with cobalt ferrite nanoparticles at specific concentrations that demonstrated a decrease in survival fraction based on colony formation assay compared to cells that were treated alone with nanoparticles or with RF-MF.

Dynamical analysis of a ferrofluid subjected to oscillatory field and shear rates: Applications to magnetic hyperthermia

The dynamical magnetic response of a small sample of ferrofluid is investigated numerically. A validated in-house research code is used to compute the translational and rotational motion of the particles. This code uses a robust scheme of Ewald summation to compute long-range periodic torques and forces between the particles. The model of the ferrofluid consists in a suspension of magnetic hard spheres replicated in lattices to ensure the convergence of the system’s transport properties. Ensemble averages over several realizations for each simulation are carried out. The suspension is subjected to field and shear time-dependent excitations. The effect of magnetic hyperthermia is evaluated by the average rate of internal energy dissipation due to an oscillatory magnetic field and oscillatory shear rate. Nonlinear dynamical tools such as phase spaces and Poincaré maps are applied to interpret the dynamical behavior of the suspension. Results show that when the suspension reaches its saturation magnetization due to a delayed time-response of the particles the internal energy dissipation decreases with respect to the local applied field. The Poincaré maps reveal that in dilute regimes the system presents quasi-periodic behavior for an alternating magnetic field. Also, the application of an oscillatory shear-rate increases the bulk internal energy of the system due to the magneto-viscous effect, even though it diminishes the internal area of the hysteresis loop. This work brings a better understanding of the dynamical response of ferrofluids that could be useful in magnetic hyperthermia applications.

Sm Doped Cu–Ni Spinel Ferrite Nanoparticles for Hyperthermia and Photocatalytic Applications

Sm Doped Cu–Ni Spinel Ferrite Nanoparticles for Hyperthermia and Photocatalytic Applications