Journal articles: 'High-frequency hyperthermia'

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Tapper, Simon, Joseph J. Nocera, and Gary Burness. "Experimental evidence that hyperthermia limits offspring provisioning in a temperate-breeding bird." Royal Society Open Science 7, no. 10 (October 2020): 201589. http://dx.doi.org/10.1098/rsos.201589.

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In many vertebrates, parental care can require long bouts of daily exercise that can span several weeks. Exercise, especially in the heat, raises body temperature, and can lead to hyperthermia. Typical strategies for regulating body temperature during endurance exercise include modifying performance to avoid hyperthermia (anticipatory regulation) and allowing body temperature to rise above normothermic levels for brief periods of time (facultative hyperthermia). Facultative hyperthermia is commonly employed by desert birds to economize on water, but this strategy may also be important for chick-rearing birds to avoid reducing offspring provisioning when thermoregulatory demands are high. In this study, we tested how chick-rearing birds balance their own body temperature against the need to provision dependent offspring. We experimentally increased the heat dissipation capacity of breeding female tree swallows ( Tachycineta bicolor ) by trimming their ventral feathers and remotely monitored provisioning rates, body temperature and the probability of hyperthermia. Birds with an experimentally increased capacity to dissipate heat (i.e. trimmed treatment) maintained higher feeding rates than controls at high ambient temperatures (greater than or equal to 25°C), while maintaining lower body temperatures. However, at the highest temperatures (greater than or equal to 25°C), trimmed individuals became hyperthermic. These results provide evidence that chick-rearing tree swallows use both anticipatory regulation and facultative hyperthermia during endurance performance. With rising global temperatures, individuals may need to increase their frequency of facultative hyperthermia to maintain nestling provisioning, and thereby maximize reproductive success.

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Barker, WJ, JT Amsterdam, SA Syverud, JR Hedges, and JS Huff. "High-frequency jet ventilation cooling in a canine hyperthermia model." Annals of Emergency Medicine 14, no. 5 (May 1985): 501–2. http://dx.doi.org/10.1016/s0196-0644(85)80367-x.

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Barker, William J., James T. Amsterdam, Scott A. Syverud, Jerris R. Hedges, and J. Stephen Huff. "High-frequency jet ventilation cooling in a canine hyperthermia model." Annals of Emergency Medicine 15, no. 6 (June 1986): 680–84. http://dx.doi.org/10.1016/s0196-0644(86)80425-5.

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Nomura, Shinichi, and Takanori Isobe. "Design Study on High-Frequency Magnets for Magnetic Hyperthermia Applications." IEEE Transactions on Applied Superconductivity 28, no. 3 (April 2018): 1–7. http://dx.doi.org/10.1109/tasc.2018.2800056.

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Kobayashi, Katsuhiro, Iori Ohmori, Keiichiro Hayashi, Yuichiro Kitagawa, Mamoru Ouchida, Takushi Inoue, and Yoko Ohtsuka. "High-frequency EEG oscillations in hyperthermia-induced seizures of Scn1a mutant rats." Epilepsy Research 103, no. 2-3 (February 2013): 161–66. http://dx.doi.org/10.1016/j.eplepsyres.2012.07.020.

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Zeinoun, Michael, Diego Serrano, Pablo Tezanos Medina, Oscar Garcia, Miroslav Vasic, and Jose Javier Serrano-Olmedo. "Configurable High-Frequency Alternating Magnetic Field Generator for Nanomedical Magnetic Hyperthermia Applications." IEEE Access 9 (2021): 105805–16. http://dx.doi.org/10.1109/access.2021.3099428.

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Caizer, Costica. "Optimization Study on Specific Loss Power in Superparamagnetic Hyperthermia with Magnetite Nanoparticles for High Efficiency in Alternative Cancer Therapy." Nanomaterials 11, no. 1 (December 26, 2020): 40. http://dx.doi.org/10.3390/nano11010040.

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The cancer therapy with the lowest possible toxicity is today an issue that raises major difficulties in treating malignant tumors because chemo- and radiotherapy currently used in this field have a high degree of toxicity and in many cases are ineffective. Therefore, alternative solutions are rapidly being sought in cancer therapy, in order to increase efficacy and a reduce or even eliminate toxicity to the body. One of the alternative methods that researchers believe may be the method of the future in cancer therapy is superparamagnetic hyperthermia (SPMHT), because it can be effective in completely destroying tumors while maintaining low toxicity or even without toxicity on the healthy tissues. Superparamagnetic hyperthermia uses the natural thermal effect in the destruction of cancer cells, obtained as a result of the phenomenon of superparamagnetic relaxation of the magnetic nanoparticles (SPMNPs) introduced into the tumor; SPMNPs can heat the cancer cells to 42–43 °C under the action of an external alternating magnetic field with frequency in the range of hundreds of kHz. However, the effectiveness of this alternative method depends very much on finding the optimal conditions in which this method must be applied during the treatment of cancer. In addition to the type of magnetic nanoparticles and the biocompatibility with the biological tissue or nanoparticles biofunctionalization that must be appropriate for the intended purpose a key parameter is the size of the nanoparticles. Also, establishing the appropriate parameters for the external alternating magnetic field (AMF), respectively the amplitude and frequency of the magnetic field are very important in the efficiency and effectiveness of the magnetic hyperthermia method. This paper presents a 3D computational study on specific loss power (Ps) and heating temperature (ΔT) which allows establishing the optimal conditions that lead to efficient heating of Fe3O4 nanoparticles, which were found to be the most suitable for use in superparamagnetic hyperthermia (SPMHT), as a non-invasive and alternative technique to chemo- and radiotherapy. The size (diameter) of the nanoparticles (D), the amplitude of the magnetic field (H) and the frequency (f) of AMF were established in order to obtain maximum efficiency in SPMHT and rapid heating of magnetic nanoparticles at the required temperature of 42–43 °C for irreversible destruction of tumors, without affecting healthy tissues. Also, an analysis on the amplitude of the AMF is presented, and how its amplitude influences the power loss and, implicitly, the heating temperature, observables necessary in SPMHT for the efficient destruction of tumor cells. Following our 3D study, we found for Fe3O4 nanoparticles the optimal diameter of ~16 nm, the optimal range for the amplitude of the magnetic field of 10–25 kA/m and the optimal frequency within the biologically permissible limit in the range of 200–500 kHz. Under the optimal conditions determined for the nanoparticle diameter of 16.3 nm, the magnetic field of 15 kA/m and the frequency of 334 kHz, the magnetite nanoparticles can be quickly heated to obtain the maximum hyperthermic effect on the tumor cells: in only 4.1–4.3 s the temperature reaches 42–43 °C, required in magnetic hyperthermia, with major benefits in practical application in vitro and in vivo, and later in clinical trials.

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Gkanas, Evangelos. "In vitro magnetic hyperthermia response of iron oxide MNP’s incorporated in DA3, MCF-7 and HeLa cancer cell lines." Open Chemistry 11, no. 7 (July 1, 2013): 1042–54. http://dx.doi.org/10.2478/s11532-013-0246-z.

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AbstractIn the current work, iron oxide magnetic nanoparticles (MNP’s) were synthesized by thermal decomposition of Fe(acac)3-(iron acetylacetonate) compounds in high-boiling organic solvents containing stabilizing surfactants and examined as possible agents for magnetic hyperthermia treatment, according to their structural, magnetic and heating properties. Three different cancer cell lines (DA3, MCF-7 and HeLa cell lines) were used to assess the suitability of the MNP’s. The experimental results proved that the synthesized MNPs are non-toxic and the uptake efficiency was extremely good. Further, from in vitro hyperthermia results, very fast thermal response was observed (reaching hyperthermia levels in less than 200 s), which minimize the duration of the cell and human body exposure in a high frequency AC external magnetic field.

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Xu, Hang, Shinichi Nomura, and Takanori Isobe. "Design and Development of a High-Frequency Magnet Prototype for Magnetic Hyperthermia Applications." IEEE Transactions on Applied Superconductivity 30, no. 4 (June 2020): 1–6. http://dx.doi.org/10.1109/tasc.2020.2978791.

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Ibarra M, Carlos A., Shiwen Wu, Kumiko Murayama, Narihiro Minami, Yasuko Ichihara, Hirosato Kikuchi, Satoru Noguchi, Yukiko K. Hayashi, Ryoichi Ochiai, and Ichizo Nishino. "Malignant Hyperthermia in Japan." Anesthesiology 104, no. 6 (June 1, 2006): 1146–54. http://dx.doi.org/10.1097/00000542-200606000-00008.

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Background Malignant hyperthermia (MH) is a disorder of calcium homeostasis in skeletal muscle triggered by volatile anesthetics or succinylcholine in susceptible persons. More than 100 mutations in the ryanodine receptor type 1 gene (RYR1) have been associated with MH susceptibility, central core disease, or both. RYR1 mutations may account for up to 70% of MH-susceptible cases. The authors aimed to determine the frequency and distribution of RYR1 mutations in the Japanese MH-susceptible population. Methods The authors selected 58 unrelated Japanese diagnosed as MH-susceptible for having an enhanced Ca-induced Ca release rate from the sarcoplasmic reticulum on chemically skinned muscle fibers. They sequenced the entire RYR1 coding region from genomic DNA. Muscle pathology was also characterized. Results Seven previously reported and 26 unknown RYR1 potentially pathogenic sequence variations were identified in 33 patients (56.9%). Of these patients, 48% had cores on muscle biopsy. The mutation detection rate was higher in patients with clear enhancement of Ca-induced Ca release rate (72.4%), whereas all patients with central core disease had RYR1 mutations. Six patients harbored potentially causative compound heterozygous sequence variations. Conclusions Distribution and frequency of RYR1 mutations differed markedly from those of the North American and European MH-susceptible population. Comprehensive screening of the RYR1 gene is recommended for molecular investigations in MH-susceptible individuals, because many mutations are located outside the "hot spots." Based on the observed occurrence of compound heterozygous state, the prevalence of a possibly predisposing phenotype in the Japanese population might be as high as 1 in 2,000 people.

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Hiranandani, Nitisha, Kenneth D. Varian, Michelle M. Monasky, and Paul M. L. Janssen. "Frequency-dependent contractile response of isolated cardiac trabeculae under hypo-, normo-, and hyperthermic conditions." Journal of Applied Physiology 100, no. 5 (May 2006): 1727–32. http://dx.doi.org/10.1152/japplphysiol.01244.2005.

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The body is from time to time exposed to nonnormothermic conditions; both hypo- and hyperthermia can occur as a result of external (environment) or internal (pathogens, allergens) stressors. To preserve life under hypo- and hyperthermic conditions, adequate perfusion of vital organs is mandated. Although cardiac output regulation under hyperthermic conditions has been studied, the mechanical response of basic contractile function of the myocardium itself is incompletely understood. Accordingly, we set out to test mechanical output of isolated myocardium under hyperthermic conditions and to compare the results with the hypo- and normothermic response in the same tissue. We observed that, in absence of a frequency change, developed force decreased markedly. At a physiological normal stimulation rate of 6 Hz, developed force decreases to 67.2 ± 2.6% at 42°C compared with 37°C. In addition, twitch timing characteristics also accelerate, allowing for a faster relaxation; time from peak tension to 50% relaxation is ∼23% faster (from 31.4 ± 2.6 to 24.4 ± 1.7 ms). Although this faster relaxation in turn prevents a steep increase in diastolic tension at high frequencies, the very fast calcium kinetics now prevent a more complete activation of the myofilaments, resulting in a lower twitch-force maximum at hyperthermic conditions. Even at maximal β-adrenergic stimulation, developed force is well below levels reached at physiological temperature.

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Usov, N. A. "Iron Oxide Nanoparticles for Magnetic Hyperthermia." SPIN 09, no. 02 (June 2019): 1940001. http://dx.doi.org/10.1142/s2010324719400010.

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Assemblies of magnetic nanoparticles show a great potential for application in biomedicine, particularly, magnetic hyperthermia. However, to achieve desired therapeutic effect in magnetic hyperthermia, the assembly of nanoparticles should have a sufficiently high specific absorption rate (SAR) in alternating magnetic field of moderate amplitude and frequency. Using the Landau–Lifshitz stochastic equation, it is shown that dilute assemblies of iron oxide nanoparticles of optimal diameters are capable of providing SAR of the order of 400–600[Formula: see text]W/g in alternating magnetic field with the amplitude [Formula: see text][Formula: see text]Oe in the frequency range f = 300–500[Formula: see text]kHz. Unfortunately, in dense clusters of magnetic nanoparticles, which are often formed in a biological medium, there is a sharp decrease in SAR due to the influence of strong magneto-dipole interaction of closest nanoparticles. To overcome this difficulty, it is suggested covering the nanoparticles with nonmagnetic shells of sufficient thickness or using non-single-domain nanoparticles being in magnetization curling states.

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Mazon, E. E., E. Villa-Martínez, A. Hernández-Sámano, T. Córdova-Fraga, J. J. Ibarra-Sánchez, H. A. Calleja, J. A. Leyva Cruz, et al. "A high-resolution frequency variable experimental setup for studying ferrofluids used in magnetic hyperthermia." Review of Scientific Instruments 88, no. 8 (August 2017): 084705. http://dx.doi.org/10.1063/1.4998975.

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Skumiel, Andrzej. "Generation of a rotating high frequency magnetic field designed for use in magnetic hyperthermia." Journal of Magnetism and Magnetic Materials 553 (July 2022): 169294. http://dx.doi.org/10.1016/j.jmmm.2022.169294.

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Chystiakov, Roman. "Prospects for the use of the method of intravesical hyperthermic chemotherapy in the treatment of patients with non-muscle invasive bladder cancer." ScienceRise: Medical Science, no. 2(41) (April 5, 2021): 22–27. http://dx.doi.org/10.15587/2519-4798.2021.228185.

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The aim: to compare disease-free survival time (DFS) in high-risk non-muscle-invasive bladder cancer patients treated with adjuvant hyperthermic intravesical chemotherapy and standard BCG therapy. Materials and methods: patients were divided into 2 groups. Group 1 (control) included patients who received adjuvant therapy after TURB with BCG vaccine (BCG therapy group; n=50), group 2 (study group) included patients (HIVEC® therapy group; n=46 ), who received adjuvant intravesical chemotherapy using a Combat BRS HIVEC® device for local hyperthermia. Results: median follow-up was 23 months (range 4 - 36). Tumor recurrence was reported in 19 patients receiving intravesical BCG therapy and in 8 patients receiving intravesical hyperthermic chemotherapy. The incidence of DFS in patients receiving chemohyperthermy was statistically higher than in patients receiving BCG therapy (log-rank test result: p=0.029). Conclusions: The method of hyperthermic intravesical chemotherapy significantly increased the 2-year disease-free survival rate - 82.6 % versus 62 % BCG therapy group (p=0.025). Its use in the future will allow increasing the frequency of organ-preserving treatment of patients with primary and recurrent muscular-non-invasive bladder tumors

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Klose, Markus K., David Chu, Chengfeng Xiao, Laurent Seroude, and R. Meldrum Robertson. "Heat Shock–Mediated Thermoprotection of Larval Locomotion Compromised by Ubiquitous Overexpression of Hsp70 in Drosophila melanogaster." Journal of Neurophysiology 94, no. 5 (November 2005): 3563–72. http://dx.doi.org/10.1152/jn.00723.2005.

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Maintaining the competence of locomotor circuitry under stressful conditions can benefit organisms by enabling locomotion to more tolerable microhabitats. We show that prior heat shock protects locomotion and the locomotor central pattern generator of larval Drosophila against subsequent hyperthermic stress. We combined molecular genetic, electrophysiological, and behavioral techniques to investigate heat shock–mediated thermoprotection. Prior heat shock increased the distance traveled by larvae during hyperthermia before failure. The frequency of the rhythm of peristaltic locomotor contractions and the velocity of locomotion were both less thermosensitive after heat shock and were less susceptible to failure at high temperatures. Rhythmic coordinated motor patterns, recorded intracellularly as excitatory junction potentials in body wall muscles of dissected preparations, were centrally generated because patterns could still be generated in the absence of sensory feedback (sensory function disrupted with shibire). Prior heat shock protected central circuit operation during hyperthermic stress by increasing the temperature at which it failed. Overexpression of Hsp70 after a heat shock using transgenic flies ( traII) did not enhance thermoprotection, as expected, but had deleterious effects on parameters of behavior.

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Hallali, N., P. Clerc, D. Fourmy, V. Gigoux, and J. Carrey. "Influence on cell death of high frequency motion of magnetic nanoparticles during magnetic hyperthermia experiments." Applied Physics Letters 109, no. 3 (July 18, 2016): 032402. http://dx.doi.org/10.1063/1.4958989.

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Kosheleva, Аngelina, and Еgor Bobkov. "Research into Silicon Nanoparticles as Agents for UHF Hyperthermia In Vitro." Journal of Biomedical Photonics & Engineering 7, no. 1 (March 31, 2021): 010306. http://dx.doi.org/10.18287/jbpe21.07.010306.

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The current approaches to cancer treatment, including surgery and high-energy beam irradiation, do not always give satisfactory results for a number of oncological neoplasms. One of the promising areas in oncology is the use of nanoparticles selectively heated by external action as agents for hyperthermia of some types of tumors. In this work, we performed selective heating of suspensions of silicon nanoparticles using a device for electromagnetic high-frequency therapy (UHF-60).

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Darwish, Mohamed S. A., Hohyeon Kim, Hwangjae Lee, Chiseon Ryu, Jae Young Lee, and Jungwon Yoon. "Engineering Core-Shell Structures of Magnetic Ferrite Nanoparticles for High Hyperthermia Performance." Nanomaterials 10, no. 5 (May 21, 2020): 991. http://dx.doi.org/10.3390/nano10050991.

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Magnetic ferrite nanoparticles (MFNs) with high heating efficiency are highly desirable for hyperthermia applications. As conventional MFNs usually show low heating efficiency with a lower specific loss power (SLP), extensive efforts to enhance the SLP of MFNs have been made by varying the particle compositions, sizes, and structures. In this study, we attempted to increase the SLP values by creating core-shell structures of MFNs. Accordingly, first we synthesized three different types of core ferrite nanoparticle of magnetite (mag), cobalt ferrite (cf) and zinc cobalt ferrite (zcf). Secondly, we synthesized eight bi-magnetic core-shell structured MFNs; Fe3O4@CoFe2O4 (mag@cf1, mag@cf2), CoFe2O4@Fe3O4 (cf@mag1, cf@mag2), Fe3O4@ZnCoFe2O4 (mag@zcf1, mag@zcf2), and ZnCoFe2O4@Fe3O4 (zcf@mag1, zcf@mag2), using a modified controlled co-precipitation process. SLP values of the prepared core-shell MFNs were investigated with respect to their compositions and core/shell dimensions while varying the applied magnetic field strength. Hyperthermia properties of the prepared core-shell MFNs were further compared to commercial magnetic nanoparticles under the safe limits of magnetic field parameters (<5 × 109 A/(m·s)). As a result, the highest SLP value (379.2 W/gmetal) was obtained for mag@zcf1, with a magnetic field strength of 50 kA/m and frequency of 97 kHz. On the other hand, the lowest SLP value (1.7 W/gmetal) was obtained for cf@mag1, with a magnetic field strength of 40 kA/m and frequency of 97 kHz. We also found that magnetic properties and thickness of the shell play critical roles in heating efficiency and hyperthermia performance. In conclusion, we successfully enhanced the SLP of MFNs by engineering their compositions and dimensions.

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Sanad, Mohamed F., Bianca P. Meneses-Brassea, Dawn S. Blazer, Shirin Pourmiri, George C. Hadjipanayis, and Ahmed A. El-Gendy. "Superparamagnetic Fe/Au Nanoparticles and Their Feasibility for Magnetic Hyperthermia." Applied Sciences 11, no. 14 (July 20, 2021): 6637. http://dx.doi.org/10.3390/app11146637.

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Today, magnetic hyperthermia constitutes a complementary way to cancer treatment. This article reports a promising aspect of magnetic hyperthermia addressing superparamagnetic and highly Fe/Au core-shell nanoparticles. Those nanoparticles were prepared using a wet chemical approach at room temperature. We found that the as-synthesized core shells assembled with spherical morphology, including face-centered-cubic Fe cores coated and Au shells. The high-resolution transmission microscope images (HRTEM) revealed the formation of Fe/Au core/shell nanoparticles. The magnetic properties of the samples showed hysteresis loops with coercivity (HC) close to zero, revealing superparamagnetic-like behavior at room temperature. The saturation magnetization (MS) has the value of 165 emu/g for the as-synthesized sample with a Fe:Au ratio of 2:1. We also studied the feasibility of those core-shell particles for magnetic hyperthermia using different frequencies and different applied alternating magnetic fields. The Fe/Au core-shell nanoparticles achieved a specific absorption rate of 50 W/g under applied alternating magnetic field with amplitude 400 Oe and 304 kHz frequency. Based on our findings, the samples can be used as a promising candidate for magnetic hyperthermia for cancer therapy.

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Yamada, S., Y. Ikehata, R. Hayashi, T. Ueno, and M. Kakikawa. "Increase in High-Frequency Magnetic Fields due to Parallel Coils Added to Applicator for Hyperthermia Therapy." Journal of the Magnetics Society of Japan 39, no. 2 (2015): 80–84. http://dx.doi.org/10.3379/msjmag.1503r006.

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Mille, N., D. De Masi, S. Faure, J. M. Asensio, B. Chaudret, and J. Carrey. "Probing dynamics of nanoparticle chains formation during magnetic hyperthermia using time-dependent high-frequency hysteresis loops." Applied Physics Letters 119, no. 2 (July 12, 2021): 022407. http://dx.doi.org/10.1063/5.0056449.

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Kuehne, Andre, Eva Oberacker, Helmar Waiczies, and Thoralf Niendorf. "Solving the Time- and Frequency-Multiplexed Problem of Constrained Radiofrequency Induced Hyperthermia." Cancers 12, no. 5 (April 25, 2020): 1072. http://dx.doi.org/10.3390/cancers12051072.

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Targeted radiofrequency (RF) heating induced hyperthermia has a wide range of applications, ranging from adjunct anti-cancer treatment to localized release of drugs. Focal RF heating is usually approached using time-consuming nonconvex optimization procedures or approximations, which significantly hampers its application. To address this limitation, this work presents an algorithm that recasts the problem as a semidefinite program and quickly solves it to global optimality, even for very large (human voxel) models. The target region and a desired RF power deposition pattern as well as constraints can be freely defined on a voxel level, and the optimum application RF frequencies and time-multiplexed RF excitations are automatically determined. 2D and 3D example applications conducted for test objects containing pure water (rtarget = 19 mm, frequency range: 500–2000 MHz) and for human brain models including brain tumors of various size (r1 = 20 mm, r2 = 30 mm, frequency range 100–1000 MHz) and locations (center, off-center, disjoint) demonstrate the applicability and capabilities of the proposed approach. Due to its high performance, the algorithm can solve typical clinical problems in a few seconds, making the presented approach ideally suited for interactive hyperthermia treatment planning, thermal dose and safety management, and the design, rapid evaluation, and comparison of RF applicator configurations.

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Chen, J. L. "PP-042 Clinical research of HG-2000 regional high-frequency hyperthermia combined with TACE in hepatocellular carcinoma." International Journal of Infectious Diseases 12 (November 2008): S67—S68. http://dx.doi.org/10.1016/s1201-9712(09)60193-4.

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Choynzonov, E. L., A. I. Ryabova, I. A. Miloichikova, N. D. Turgunova, O. V. Gribova, Zh A. Startseva, V. A. Novikov, et al. "Measurement of the Temperature Field in a Brain Phantom with Simulated Glioblastoma in Transcranial High-Frequency Hyperthermia." Biomedical Engineering 51, no. 5 (January 2018): 350–53. http://dx.doi.org/10.1007/s10527-018-9746-7.

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Nowak, G., O. Rentzsch, A. J. A. Terzis, and H. Arnold. "Induced hyperthermia in brain tissue: Comparison between contact Nd:YAG laser system and automatically controlled high frequency current." Acta Neurochirurgica 102, no. 1-2 (March 1990): 76–81. http://dx.doi.org/10.1007/bf01402191.

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Morales, Irene, Rocio Costo, Nicolas Mille, Gustavo da Silva, Julian Carrey, Antonio Hernando, and Patricia de la Presa. "High Frequency Hysteresis Losses on γ-Fe2O3 and Fe3O4: Susceptibility as a Magnetic Stamp for Chain Formation." Nanomaterials 8, no. 12 (November 24, 2018): 970. http://dx.doi.org/10.3390/nano8120970.

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In order to understand the properties involved in the heating performance of magnetic nanoparticles during hyperthermia treatments, a systematic study of different γ-Fe2O3 and Fe3O4 nanoparticles has been done. High-frequency hysteresis loops at 50 kHz carried out on particles with sizes ranging from 6 to 350 nm show susceptibility χ increases from 9 to 40 for large particles and it is almost field independent for the smaller ones. This suggests that the applied field induces chain ordering in large particles but not in the smaller ones due to the competition between thermal and dipolar energy. The specific absorption rate (SAR) calculated from hysteresis losses at 60 mT and 50 kHz ranges from 30 to 360 W/gFe, depending on particle size, and the highest values correspond to particles ordered in chains. This enhanced heating efficiency is not a consequence of the intrinsic properties like saturation magnetization or anisotropy field but to the spatial arrangement of the particles.

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HEYDARI, MORTEZA, MEHRDAD JAVIDI, MOHAMMAD MAHDI ATTAR, ALIREZA KARIMI, MAHDI NAVIDBAKHSH, MOHAMMAD HAGHPANAHI, and SAEID AMANPOUR. "MAGNETIC FLUID HYPERTHERMIA IN A CYLINDRICAL GEL CONTAINS WATER FLOW." Journal of Mechanics in Medicine and Biology 15, no. 05 (October 2015): 1550088. http://dx.doi.org/10.1142/s0219519415500888.

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In magnetic fluid hyperthermia (MFH), nanoparticles are injected into a diseased tissue and then subjected to an alternating high frequency magnetic field. The produced heat may have a key asset to destroy the cancerous cells. The blood flow in a tissue is considered as the most complicated part of the MFH which should be taken into account in the analysis of the MFH. This study was aimed to perform an experimental study to investigate the heat transfer of agar gel which contains fluid flow. Fe 3 O 4 as a nanoparticle was injected into the center of a cylindrical gel. It was also embedded with other cylindrical gels and subjected to an alternating magnetic field of 7.3 (kA/m) and a frequency of 50 (kHz) for 3600 (s). The temperature of the gel was measured at three points. The temperature distribution was measured via the experimental data. Moreover, specific absorption rate (SAR) was quantified with time differential temperature function at t = 0 by means of experimental data. Finite element method (FEM) was employed to establish a model to validate the SAR function. Results revealed the effects of fluid flow and accuracy of the SAR function for heat production in gel. The proposed function have implications in hyperthermia studies as a heat generation source. Finally, the condition of experimental setup was simulated to find the blood perfusion.

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zheng, Lihan, Yuanwei Chen, Ying Wang, Peng Wang, and Tao Wang. "Effect of Bi Ions on the Hyperthermia Properties of Hyaluronic Acid-Coated La1−xSrxMnO3 Nanoparticles." Nano 15, no. 01 (January 2020): 2050015. http://dx.doi.org/10.1142/s1793292020500150.

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Self-regulating temperature hyperthermia based on magnetic fluid with low Curie temperature is a moderately effective method for cancer treatment. The improvement of the properties of magnetic fluids is the key for application of this method. In this paper, Bi-doped LSMO magnetic nanoparticles were synthesized using a simple sol–gel method and coated by hyaluronic acid through high energy ball milling for their possible application in self-regulating temperature hyperthermia. The crystal structure, morphology, basic magnetic properties and heating properties of these nanoparticles in a high frequency magnetic field were investigated. It was found that the hyaluronic acid-coated La[Formula: see text]Sr[Formula: see text]Bi[Formula: see text]MnO3 magnetic nanoparticles, with an average particle diameter of [Formula: see text]100[Formula: see text]nm and a Curie temperature of 48∘C, possess outstanding induction heating properties. The saturation heating temperature, specific absorption rate and effective specific absorption rate are 48∘C, 117[Formula: see text]W/g and 0.27[Formula: see text]W/g[Formula: see text]kHz[Formula: see text](kA/m2), respectively.

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Jabalera, Ylenia, Alberto Sola-Leyva, María P. Carrasco-Jiménez, Guillermo R. Iglesias, and Concepcion Jimenez-Lopez. "Synergistic Photothermal-Chemotherapy Based on the Use of Biomimetic Magnetic Nanoparticles." Pharmaceutics 13, no. 5 (April 28, 2021): 625. http://dx.doi.org/10.3390/pharmaceutics13050625.

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MamC-mediated biomimetic magnetic nanoparticles (BMNPs) have emerged as one of the most promising nanomaterials due to their magnetic features (superparamagnetic character and large magnetic moment per particle), their novel surface properties determined by MamC, their biocompatibility and their ability as magnetic hyperthermia agents. However, the current clinical application of magnetic hyperthermia is limited due to the fact that, in order to be able to reach an effective temperature at the target site, relatively high nanoparticle concentration, as well as high magnetic field strength and/or AC frequency are needed. In the present study, the potential of BMNPs to increase the temperature upon irradiation of a laser beam in the near infrared, at a wavelength at which tissues become partially transparent, is explored. Moreover, our results also demonstrate the synergy between photothermia and chemotherapy in terms of drug release and cytotoxicity, by using BMNPs functionalized with doxorubicin, and the effectiveness of this combination therapy against tumor cells in in vitro experiments. Therefore, the findings of the present study open the possibility of a novel, alternative approach to fight localized tumors.

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Svetitsky, P. V. "Effect of mircowave and ionizing radiation in patients with recurrent laryngeal carcinoma." Journal of Laryngology & Otology 104, no. 9 (September 1990): 704–5. http://dx.doi.org/10.1017/s0022215100113672.

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AbstractThis study describes the treatment and survival of 54 patients with gross recurrent laryngeal carcinoma after radiotherapy. Twenty-six patients were treated with local ultra-high frequency hyperthermia in combination with radiotherapy and chemotherapy (HRCH). Twenty-eight control patients were treated with radiotherapy and chemotherapy (RCh). Eight patients (33 per cent) in HRCh showed a three year survival but no patient in the RCh group. At two years 18 patients (75 per cent) in HRCh and two (7 per cent) in RCh survived.

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Rodrigo, Irati, Idoia Castellanos-Rubio, Eneko Garaio, Oihane K. Arriortua, Maite Insausti, Iñaki Orue, José Ángel García, and Fernando Plazaola. "Exploring the potential of the dynamic hysteresis loops via high field, high frequency and temperature adjustable AC magnetometer for magnetic hyperthermia characterization." International Journal of Hyperthermia 37, no. 1 (January 1, 2020): 976–91. http://dx.doi.org/10.1080/02656736.2020.1802071.

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Darwish, Mohamed S. A., Hohyeon Kim, Minh Phu Bui, Tuan-Anh Le, Hwangjae Lee, Chiseon Ryu, Jae Young Lee, and Jungwon Yoon. "The Heating Efficiency and Imaging Performance of Magnesium Iron Oxide@tetramethyl Ammonium Hydroxide Nanoparticles for Biomedical Applications." Nanomaterials 11, no. 5 (April 23, 2021): 1096. http://dx.doi.org/10.3390/nano11051096.

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Multifunctional magnetic nanomaterials displaying high specific loss power (SLP) and high imaging sensitivity with good spatial resolution are highly desired in image-guided cancer therapy. Currently, commercial nanoparticles do not sufficiently provide such multifunctionality. For example, Resovist® has good image resolution but with a low SLP, whereas BNF® has a high SLP value with very low image resolution. In this study, hydrophilic magnesium iron oxide@tetramethyl ammonium hydroxide nanoparticles were prepared in two steps. First, hydrophobic magnesium iron oxide nanoparticles were fabricated using a thermal decomposition technique, followed by coating with tetramethyl ammonium hydroxide. The synthesized nanoparticles were characterized using XRD, DLS, TEM, zeta potential, UV-Vis spectroscopy, and VSM. The hyperthermia and imaging properties of the prepared nanoparticles were investigated and compared to the commercial nanoparticles. One-dimensional magnetic particle imaging indicated the good imaging resolution of our nanoparticles. Under the application of a magnetic field of frequency 614.4 kHz and strength 9.5 kA/m, nanoparticles generated heat with an SLP of 216.18 W/g, which is much higher than that of BNF (14 W/g). Thus, the prepared nanoparticles show promise as a novel dual-functional magnetic nanomaterial, enabling both high performance for hyperthermia and imaging functionality for diagnostic and therapeutic processes.

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Ma, Liqiu, Ryosuke Kambe, Tomoko Tsuchiya, Shiro Kanegasaki, and Akihisa Takahashi. "Anti-Metastatic Benefits Produced by Hyperthermia and a CCL3 Derivative." Cancers 11, no. 11 (November 11, 2019): 1770. http://dx.doi.org/10.3390/cancers11111770.

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Significant numbers of malignant tumor cells that have spread to surrounding tissues and other distant organs are often too small to be picked up in a diagnostic test, and prevention of even such small metastases should improve patient outcomes. Using a mouse model, we show in this article that intravenous administration of a human CCL3 variant carrying a single amino acid substitution after mild local hyperthermia not only induces tumor growth inhibition at the treated site but also inhibits metastasis. Colon26 adenocarcinoma cells (1 × 105 cells/mouse) were grafted subcutaneously into the right hind leg of syngeneic BALB/c mice and after nine days, when tumor size reached ~11 mm in diameter, the local tumor mass was exposed to high-frequency waves, by which intratumoral temperature was maintained at 42 °C for 30 min. Mice received the CCL3 variant named eMIP (2 μg/mouse/day) intravenously for five consecutive days starting one day after heat treatment. We found that tumor growth in eMIP recipients after hyperthermia was inhibited markedly but no effect was seen in animals treated with either hyperthermia or eMIP alone. Furthermore, the number of lung metastases evaluated after 18 days was dramatically reduced in animals receiving the combination therapy compared with all other controls. These results encourage future clinical application of this combination therapy.

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Pozdeev, N. M., Yu V. Zinov'ev, S. A. Kozlov, and N. V. Ryabov. "Adjuvant Effect of High-Frequency Hyperthermia of the Abdominal Cavity on the Course of Transplanted Leukemia in AKR Mice." Bulletin of Experimental Biology and Medicine 137, no. 5 (May 2004): 490–92. http://dx.doi.org/10.1023/b:bebm.0000038161.37752.d6.

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Ortega-Muñoz, Mariano, Simona Plesselova, Angel V. Delgado, Francisco Santoyo-Gonzalez, Rafael Salto-Gonzalez, Maria Dolores Giron-Gonzalez, Guillermo R. Iglesias, and Francisco Javier López-Jaramillo. "Poly(ethylene-imine)-Functionalized Magnetite Nanoparticles Derivatized with Folic Acid: Heating and Targeting Properties." Polymers 13, no. 10 (May 15, 2021): 1599. http://dx.doi.org/10.3390/polym13101599.

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Magnetite nanoparticles (MNPs) coated by branched poly (ethylene-imine) (PEI) were synthesized in a one-pot. Three molecular weights of PEI were tested, namely, 1.8 kDa (sample MNP-1), 10 kDa (sample MNP-2), and 25 kDa (sample MNP-3). The MNP-1 particles were further functionalized with folic acid (FA) (sample MNP-4). The four types of particles were found to behave magnetically as superparamagnetic, with MNP-1 showing the highest magnetization saturation. The particles were evaluated as possible hyperthermia agents by subjecting them to magnetic fields of 12 kA/m strength and frequencies ranging between 115 and 175 kHz. MNP-1 released the maximum heating power, reaching 330 W/g at the highest frequency, in the high side of reported values for spherical MNPs. In vitro cell viability assays of MNP-1 and MNP-4 against three cell lines expressing different levels of FA receptors (FR), namely, HEK (low expression), and HeLa (high expression), and HepG2 (high expression), demonstrated that they are not cytotoxic. When the cells were incubated in the presence of a 175 kHz magnetic field, a significant reduction in cell viability and clone formation was obtained for the high expressing FR cells incubated with MNP-4, suggesting that MNP-4 particles are good candidates for magnetic field hyperthermia and active targeting.

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Zhang, Xuefeng, Shihwei Chen, Huay-Min Wang, Shu-Ling Hsieh, Chun-Hsin Wu, Hsuan-Hung Chou, and Shuchen Hsieh. "ROLE OF NÉEL AND BROWNIAN RELAXATION MECHANISMS FOR WATER-BASED Fe3O4 NANOPARTICLE FERROFLUIDS IN HYPERTHERMIA." Biomedical Engineering: Applications, Basis and Communications 22, no. 05 (October 2010): 393–99. http://dx.doi.org/10.4015/s1016237210002158.

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Hydrophilic Fe3O4 nanoparticles with a mean diameter size of 15 nm were synthesized by means of the direct reduction of FeCl3 and FeCl2 in an aqueous solution. The heating properties of Fe3O4 nanoparticles under an alternating magnetic field were investigated in a frequency range of 50–500 kHz and a magnitude range of 3.1–5.0 kA/m. To distinguish the roles of Néel and Brownian relaxation mechanisms, polydimethylsiloxane (PDMS) and water were employed as a medium, in which PDMS plays a significant role of eliminating the effect of Brownian relaxation. It is experimentally and theoretically confirmed that, for the Fe3O4 /water system, high-specific absorption rates are due to a combination of both mechanisms, with an enhanced contribution due to Néel relaxation with increasing frequency and magnitude of the alternating electromagnetic field. The contribution efficiency of Néel relaxation increases from 36–56% by increasing the electromagnetic field frequency from 50–300 kHz, and then retains a saturated value of ~ 56% at 300–500 kHz. Moreover, a linear increase of the contribution efficiency of Néel relaxation at 300 kHz was observed from 55–65% by increasing the magnitude of electromagnetic field at 3.1–5.0 kA/m. The current research can be widely-expanded to explain the electromagnetic heating effect of other ferrofluid systems.

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Fizesan, Ionel, Cristian Iacovita, Anca Pop, Bela Kiss, Roxana Dudric, Rares Stiufiuc, Constantin Mihai Lucaciu, and Felicia Loghin. "The Effect of Zn-Substitution on the Morphological, Magnetic, Cytotoxic, and In Vitro Hyperthermia Properties of Polyhedral Ferrite Magnetic Nanoparticles." Pharmaceutics 13, no. 12 (December 14, 2021): 2148. http://dx.doi.org/10.3390/pharmaceutics13122148.

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The clinical translation of magnetic hyperthermia (MH) needs magnetic nanoparticles (MNPs) with enhanced heating properties and good biocompatibility. Many studies were devoted lately to the increase in the heating power of iron oxide MNPs by doping the magnetite structure with divalent cations. A series of MNPs with variable Zn/Fe molar ratios (between 1/10 and 1/1) were synthesized by using a high-temperature polyol method, and their physical properties were studied with different techniques (Transmission Electron Microscopy, X-ray diffraction, Fourier Transform Infrared Spectroscopy). At low Zn doping (Zn/Fe ratio 1/10), a significant increase in the saturation magnetization (90 e.m.u./g as compared to 83 e.m.u./g for their undoped counterparts) was obtained. The MNPs’ hyperthermia properties were assessed in alternating magnetic fields up to 65 kA/m at a frequency of 355 kHz, revealing specific absorption rates of up to 820 W/g. The Zn ferrite MNPs showed good biocompatibility against two cell lines (A549 cancer cell line and BJ normal cell line) with a drop of only 40% in the viability at the highest dose used (500 μg/cm2). Cellular uptake experiments revealed that the MNPs enter the cells in a dose-dependent manner with an almost 50% higher capacity of cancer cells to accommodate the MNPs. In vitro hyperthermia data performed on both cell lines indicate that the cancer cells are more sensitive to MH treatment with a 90% drop in viability after 30 min of MH treatment at 30 kA/m for a dose of 250 μg/cm2. Overall, our data indicate that Zn doping of iron oxide MNPs could be a reliable method to increase their hyperthermia efficiency in cancer cells.

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Бурмистров, И. А., Д. Б. Трушина, Т. Н. Бородина, М. М. Веселов, Н. Л. Клячко, В. Б. Зайцев, Y. Gonzalez-Alfaro, and Т. В. Букреева. "Влияние низкочастотного магнитного поля на полиэлектролитные микрокапсулы с наночастицами магнетита." Журнал технической физики 90, no. 9 (2020): 1428. http://dx.doi.org/10.21883/jtf.2020.09.49672.405-19.

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Polyelectrolyte microcapsules have been prepared by sequential adsorption of oppositely charged sodium polystyrene sulfonate and polyallylamine hydrochloride molecules on the surface of calcium carbonate particles. The capsule shells are functionalized with Fe3O4 magnetic nanoparticles to provide control over the localization of microcapsules and the permeability of their shells. The control of microcapsule permeability using a low-frequency non-heating magnetic field is based on the magneto-mechanical actuation, which, due to its high penetration ability, locality and safety, is preferable for application in vivo to magnetic hyperthermia. Here we report on the results of analysis of the effect of a low-frequency pulsed sinusoidal magnetic field with a frequency of 50 Hz on the permeability of the microcapsule shell for fluorescently labeled dextran molecules. It was found that the permeability of the shell increases with a decrease in the duration of the pause between magnetic field pulses, causing an increase in the amount of dextran in the shell.

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Ma, Ji-Ming, Sheng-Nan Guo, Ri-Jian Su, and Wei-Na Yue. "The Method for Magnetic Hyperthermia Based on Particle Swarm Optimization Algorithm with Levy Flight." International Journal of Pattern Recognition and Artificial Intelligence 30, no. 10 (November 23, 2016): 1659025. http://dx.doi.org/10.1142/s0218001416590254.

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A new method to set up the static magnetic field of the targeted magnetic fluid hyperthermia is presented, and a new particle swarm optimization algorithm with Levy flight (LF-PSO) is proposed. Magnetic field generating system consists of 18 coils, deployed in the lesions of the peripheral symmetric space, the main principle is to heat magnetic nanoparticles by high frequency alternating magnetic field to kill the cancer cells, while building a static magnetic field in the periphery of the tumor region to protect healthy tissue from harm. Tumor location information may be shifted, so each treatment needs to reconfigure the static magnetic field. The set of magnetic heating coil currently adopted this new LF-PSO algorithm, in the reason of the particle swarm optimization algorithm with Levy flight mechanism is characterized by good robustness, high precision of optimal search and it is easy to jump out of local optimum. Experimental results show that by building a new objective function, and comparing with the FEM algorithm, the LF-PSO algorithm has advantages of fast solving speed and high accuracy.

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Gas, Piotr, Arkadiusz Miaskowski, and Mahendran Subramanian. "In Silico Study on Tumor-Size-Dependent Thermal Profiles inside an Anthropomorphic Female Breast Phantom Subjected to Multi-Dipole Antenna Array." International Journal of Molecular Sciences 21, no. 22 (November 14, 2020): 8597. http://dx.doi.org/10.3390/ijms21228597.

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

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Suzuki, O., S. Miyachi, T. Okamoto, A. Ito, M. Shinkai, H. Honda, T. Kobayashi, M. Negoro, and J. Yoshida. "Local Hyperthermia Enhances Thrombosis in Aneurysms Containing Platinum Coils." Interventional Neuroradiology 10, no. 3 (September 2004): 203–11. http://dx.doi.org/10.1177/159101990401000302.

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Despite recent technical advances in embolization of cerebral aneurysms with platinum coils, some aneurysms eventually resulted in incomplete packing with remnant neck or dome filling. Such a situation with a remaining inflow zone may pose a risk of rupture and subsequent regrowth. Metals characteristically generate heat under high-frequency alternating magnetic fields (AMF). We used this property to induce local hyperthermia and promote thrombogenesis in incompletely packed aneurysms. Glass model aneurysms packed with coils were subjected to AMF to investigate the correlation between weight of platinum and temperature elevation and the correlation between flow rates of water through the model and temperature elevation. Next, activated coagulation time (ACT) of blood obtained from dogs was studied at various temperatures. Finally, side-wall aneurysms created in the canine carotid artery using a venous patch were packed with platinum coils. Change in temperature and angiographic changes were investigated after AMF application. In the glass model, the weight of platinum was correlated with elevation of temperature, and a negative logarithmic correlation was evident between flow rate and elevation of temperature. Elevation of blood sample temperature tended to shorten ACT. In canine carotid aneurysms, elevation of intra-aneurysmal temperature was confirmed and sufficient elevation of temperature was found to promote angiographically evident thrombogenesis of the remnant space after AMF application. Local hyperthermia may be useful in completing luminal obliteration of aneurysms after coil embolization. It may particularly useful for ruptured aneurysms to prevent the early rerupture.

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HUTH, CHRISTOPHER, DONGLU SHI, FENG WANG, DONALD CARRAHAR, JIE LIAN, FENGYUAN LU, JIAMING ZHANG, RODNEY C. EWING, and GIOVANNI M. PAULETTI. "PHOSPHOLIPID ASSEMBLY ON SUPERPARAMAGNETIC NANOPARTICLES FOR THERMORESPONSIVE DRUG DELIVERY APPLICATIONS." Nano LIFE 01, no. 03n04 (September 2010): 251–61. http://dx.doi.org/10.1142/s1793984410000237.

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Thermoresponsive nanocomposites were prepared by immobilizing a 2–3 nm thick phospholipid layer on the surface of superparamagnetic Fe3O4 nanoparticles via high-affinity avidin/biotin interactions. Morphological and physicochemical surface properties were assessed using transmission electron microscopy, confocal laser scanning microscopy, differential scanning calorimetry, and attenuated total reflectance Fourier transform infrared spectroscopy. The zeta potential of Fe3O4 colloids in phosphate buffered saline (PBS) decreased from -23.6 to -5.0 mV as a consequence of phospholipid immobilization. Nevertheless, heating properties of these superparamagnetic nanoparticles within an alternating magnetic field were not significantly affected. Hyperthermia-relevant temperatures > 40°C were achieved within 10–15 min using a 7-mT magnetic field alternating at a frequency of 1 MHz. Loading of the surface-associated phospholipid layer with the hydrophobic dye dansylcadaverine was accomplished at an efficiency of 479 ng/mg Fe3O4 . Release of this drug surrogate was temperature-dependent, resulting in a 2.5-fold greater release rate when nanoparticles were exposed to a temperature above the experimentally determined melting temperature of 39.7°C. These data underline the feasibility of preparing novel, stimulus-induced drug delivery systems where payload release from a colloid-immobilized phospholipid assembly is triggered by hyperthermia.

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Klemm, P., J. Bär, I. Aykara, K. Frommer, E. Neumann, U. Müller-Ladner, and U. Lange. "POS0844 EFFECTS OF SERIAL LOCALLY APPLIED WATER-FILTERED INFRARED A RADIATION IN PATIENTS WITH SYSTEMIC SCLEROSIS WITH SEVERE RAYNAUD’S SYNDROME RECEIVING PROSTAGLANDINE TREATMENT – A RANDOMIZED CONTROLLED TRIAL." Annals of the Rheumatic Diseases 80, Suppl 1 (May 19, 2021): 676.1–676. http://dx.doi.org/10.1136/annrheumdis-2021-eular.1735.

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Background:More than 95% of patients with systemic sclerosis (SSc) suffer from Raynaud’s syndrome (RS) leading to digital ulcerations (DU). In severe RS, intravenous application of prostaglandins is required. Moreover, these patients profit from an additional non-pharmacological treatment using hyperthermia to increase vasodilatation and perfusion, and to reduce pain.Serial locally applied water-filtered infrared A radiation (sl-wIRAR) is a hyperthermia treatment modality using infrared heat radiation in the range of 780-1400nm with high tissue penetration and low thermal load on the skin surface [1]. wIRAR has both, temperature-dependent and non-dependent effects, which do not inherit thermal energy transfer and/or relevant temperature changes [1]. It is therefore not only used in acute and chronic wound healing as it promotes perfusion, alleviates pain and has anti-infectious effects [2], but is also used in oncology [3] and rheumatology [4].Objectives:We conducted a randomized controlled trial with a follow-up visit after 2 weeks to evaluate the value of a high-frequent hyperthermia treatment using sl-wIRAR in comparison to a low-frequent hyperthermia treatment (our standard) in SSc patients with severe RS receiving Iloprost treatment.Methods:Eligible patients had SSc according to the 2013 ACR/EULAR classification criteria, were 18 to 80 years old and had RS requiring treatment with Iloprost in an in-patient setting. Key exclusion criteria were contraindications to any hyperthermia treatment such as infection or heat insensitivity. The trial was conducted at Campus Kerckhoff of Justus-Liebig University Giessen. Eligible patients were equally randomized to the intervention group (IG) receiving additional sl-wIRAR treatment (2 treatments for 30 min per day for 8 days) plus the standard of care (Iloprost treatment over 8 days plus daily carbon dioxide hand baths of 20 min) and the control group (CG) receiving only the standard of care. Primary outcome was the between-group difference in pain measured on a numeric rating scale (NRS) after intervention. Key secondary outcomes included a change in RS frequency, RS duration, and a change in Interleukin (IL) -6 and VEGF levels.Results:From 01.03.2020 to 31.12.2020 49 SSc patients met the inclusion criteria. 42 patients were enrolled (IG: 21, CG: 21). 38 patients (IG:19, CG: 19) completed the full trial period and were analyzed. There was no statistically significant between-group difference in pain levels (NRS) (p=0.284, Z -1.082 (Mann-Whitney U Test)) and thus the primary outcome was not met. Therefore, all p values for secondary outcomes are nominal. Intensity (Visual analogue scale 0-100mm) and duration (min) of RS were reduced in the IG (mean ± standard error) -14.579 ± 7.214 mm (p=0.058) and -2.917 ± 1.510 min (p=0.08), respectively. Intra- and inter-group comparison of IL-6 and VEGF levels showed no relevant change.Conclusion:The additive and frequent use of sl-wIRAR in the treatment of SSc patients with RS requiring Iloprost treatment does not improve outcomes regarding pain levels, RS intensity or frequency nor IL-6 and VEGF levels when compared to Iloprost treatment and low-frequent hyperthermia application.References:[1]Hoffmann G. Clinical applications of water-filtered infrared-A (wIRA) – a review. Phys Med Rehab Kuror. 2017;27(05):265–274.[2]Hoffmann G, Harte M, Mercer JB. Heat for wounds – water-fil- tered infrared-a (wIRA) for wound healing – a review. GMS Ger Med Sci. 2016;14:Doc08.[3]Notter M, Thomsen AR, Nitsche M, et al. Combined wIRA-hyperthermia and hypofractionated re-irradiation in the treatment of locally recurrent breast cancer: evaluation of therapeutic outcome based on a novel size classification. Cancers (Basel). 2020;12(3): 606.[4]Klemm P, Eichelmann M, Aykara I et al. Serial locally applied water-filtered infrared a radiation in axial spondyloarthritis – a randomized controlled trial, International Journal of Hyperthermia, 37:1, 965-970.Acknowledgements:We acknowledge the help of Carina Schreiyäck.This study was in part supported by the Dr. med. h.c. Erwin Braun Foundation, Basel, a charitable, nonprofit Swiss scientific foundation approved by the Swiss Federal Administration. The foundation supports clinical investigation of waterfiltered infrared-A. The foundation was not involved in any content- or decision-related aspect of the study.This study was prospectively registered at www.drks.de (German Registry of Clinical Studies): DRKS00021098Disclosure of Interests:None declared

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Zverev, Vladimir, Alla Dobroserdova, Andrey Kuznetsov, Alexey Ivanov, and Ekaterina Elfimova. "Computer Simulations of Dynamic Response of Ferrofluids on an Alternating Magnetic Field with High Amplitude." Mathematics 9, no. 20 (October 14, 2021): 2581. http://dx.doi.org/10.3390/math9202581.

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The response of ferrofluids to a high-amplitude AC magnetic field is important for several applications including magnetic hyperthermia and biodetection. In computer simulations of the dynamic susceptibility of a ferrofluid outside the linear response region, there are several problems associated with the fact that an increase in the frequency of the AC field leads to the appearance of additional computational errors, which can even lead to unphysical results. In this article, we study the dependence of the computational error arising in the computer simulation of the dynamic susceptibility on the input parameters of the numerical algorithm: the length of the time step, the total number of computer simulation periods, and averaging period. Computer simulation is carried out using the Langevin dynamics method and takes Brownian rotational relaxation of magnetic particles and interparticle interactions into account. The reference theory [Yoshida T.; Enpuku K. Jap. J. Ap. Phys. 2009] is used to estimate computational error. As a result, we give practical recommendations for choosing the optimal input parameters of the numerical algorithm, which make it possible to obtain reliable results of the dynamic susceptibility of a ferrofluid in a high-amplitude AC field in a wide frequency range.

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Tan, Qiaolai, Xiao Zou, Hu Dong, Yajun Ding, and Xinmin Zhao. "Influence of Blood Vessels on Temperature during High-Intensity Focused Ultrasound Hyperthermia Based on the Thermal Wave Model of Bioheat Transfer." Advances in Condensed Matter Physics 2018 (September 6, 2018): 1–10. http://dx.doi.org/10.1155/2018/5018460.

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The coupled effects of blood vessels and thermal relaxation time on temperature and thermal lesion region in biological tissue during high-intensity focused ultrasound (HIFU) hyperthermia are numerically investigated. Considering the non-Fourier behavior of heat conduction in biological tissue, the traditional Pennes bioheat equation was modified to thermal wave model of bioheat transfer (TWMBT). Consequently, a joint physical model, which combines TWMBT for tissue and energy transport equation for blood vessel, is presented to predict the evolution of temperature and the thermal lesion region. In this study, pulsatile blood flow is first introduced into numerical study of HIFU hyperthermia, and thermal relaxation time, ultrasonic focus location, blood vessel radius, and blood flow velocity are all taken into account. The results show that the thermal relaxation time plays a key role in the temperature and the thermal lesion region. Larger thermal relaxation time results in lower temperature and smaller thermal lesion region, which indicates that TWMBT leads to lower temperature and smaller thermal lesion region compared to Pennes bioheat transfer model. In addition, we found that the ultrasonic focus location and blood vessel radius significantly affected the temperature and thermal lesion region, while the heartbeat frequency and amplitude factor of pulsating blood flow as well as the average velocity of blood flow had only a slight effect.

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Mehdaoui, B., J. Carrey, M. Stadler, A. Cornejo, C. Nayral, F. Delpech, B. Chaudret, and M. Respaud. "Influence of a transverse static magnetic field on the magnetic hyperthermia properties and high-frequency hysteresis loops of ferromagnetic FeCo nanoparticles." Applied Physics Letters 100, no. 5 (January 30, 2012): 052403. http://dx.doi.org/10.1063/1.3681361.

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Larcombe, Alexander N., Philip C. Withers, and Stewart C. Nicol. "Thermoregulatory, metabolic and ventilatory physiology of the eastern barred bandicoot (Perameles gunnii)." Australian Journal of Zoology 54, no. 1 (2006): 9. http://dx.doi.org/10.1071/zo05071.

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Thermoregulatory, metabolic and ventilatory parameters measured for the Tasmanian eastern barred bandicoot (Perameles gunnii) in thermoneutrality (ambient temperature = 30°C) were: body temperature 35.1°C, basal metabolic rate 0.55 mL O2 g–1 h–1, wet thermal conductance 2.2 mL O2 g–1 h–1 °C–1, dry thermal conductance 1.4 J g–1 h–1 °C–1, ventilatory frequency 24.8 breaths min–1, tidal volume 9.9 mL, minute volume of 246 mL min–1, and oxygen extraction efficiency 22.2%. These physiological characteristics are consistent with a cool/wet distribution, e.g. high basal metabolic rate (3.33 mL O2 g–0.75 h–1) for thermogenesis, low thermal conductance (0.92 J g–1 h–1 °C–1 at 10°C) for heat retention and intolerance of high ambient temperatures (≥35°C) with panting, hyperthermia and high total evaporative water loss (16.9 mg H2O g–1 h–1).

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Liu, Ai Hong. "Preparation and Microwave Absorption Properties of CNTs/HAp Composites for Use in Tumor Hyperthermia." Advanced Materials Research 345 (September 2011): 280–86. http://dx.doi.org/10.4028/www.scientific.net/amr.345.280.

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CNTs/HAp thermo-seed material were prepared by a simple and effective coprecipitation and hydrothermal treatment method. The phase structure, composition and morphology of CNTs/HAp composites were examined by X-ray diffraction (XRD), transmission electron microscope (TEM). The results showed that When CNTs content was 10wt%, after hydrothermal treatment, a certain high degree of crystallinity, pure component single HAp layer was obtained on the surface of CNTs successfully. The electromagnetic parameters of CNTs/HAp composites were measured in the range from 0 GHz to 5.0 GHz. The results showed that CNTs/HAp composite had better absorbing properties in the 0-5.0 GHz range. With increasing of CNTs content, the microwave absorbing capacity of CNTs/HAp composite had been gradually strengthened, the absorption peak moved towards high frequency, the bandwidth was increased. When CNTs content was 8wt%, a maximum reflection loss value of -26 dB had been obtained at 3.0 GHz. Therefore, CNTs/HAp composite material is expected as thermo-seed material for tumor hyperthermia.

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Ting, Chien-Kun, Udesh Dhawan, Ching-Li Tseng, Cihun-Siyong Alex Gong, Wai-Ching Liu, Huai-De Tsai, and Ren-Jei Chung. "Hyperthermia-Induced Controlled Local Anesthesia Administration Using Gelatin-Coated Iron–Gold Alloy Nanoparticles." Pharmaceutics 12, no. 11 (November 16, 2020): 1097. http://dx.doi.org/10.3390/pharmaceutics12111097.

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The lack of optimal methods employing nanoparticles to administer local anesthesia often results in posing severe risks such as non-biocompatibility, in vivo cytotoxicity, and drug overdose to patients. Here, we employed magnetic field-induced hyperthermia to achieve localized anesthesia. We synthesized iron–gold alloy nanoparticles (FeAu Nps), conjugated an anesthetic drug, Lidocaine, and coated the product with gelatin to increase the biocompatibility, resulting in a FeAu@Gelatin–Lidocaine nano-complex formation. The biocompatibility of this drug–nanoparticle conjugate was evaluated in vitro, and its ability to trigger local anesthesia was also evaluated in vivo. Upon exposure to high-frequency induction waves (HFIW), 7.2 ± 2.8 nm sized superparamagnetic nanoparticles generated heat, which dissociated the gelatin coating, thereby triggering Lidocaine release. MTT assay revealed that 82% of cells were viable at 5 mg/mL concentration of Lidocaine, indicating that no significant cytotoxicity was induced. In vivo experiments revealed that unless stimulated with HFIW, Lidocaine was not released from the FeAu@Gelatin–Lidocaine complex. In a proof-of-concept experiment, an intramuscular injection of FeAu@Gelatin–Lidocaine complex was administered to the rat posterior leg, which upon HFIW stimulation triggered an anesthetic effect to the injected muscle. Based on our findings, the FeAu@Gelatin–Lidocaine complex can deliver hyperthermia-induced controlled anesthetic drug release and serve as an ideal candidate for site-specific anesthesia administration.

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Journal articles on the topic 'High-frequency hyperthermia'

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