Papers by Keyword: Hyperthermia

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Authors: Jian An Liu, Mei Mei Zhang, Xue Na Yang
Abstract: A novel porous ferromagnetic glass-ceramic has been synthesized with glassceramic and hydroxyapatite for hyperthermia application. The glassceramic was obtained from a melt derived glass, and the hydroxyapatite was prepared via precipitation method with biological template (YEAST). Both components of such a mixture were sintered at 1000 °C for 1 hour in graphite. The sample was characterized by x-ray diffraction, scanning electron microscopy and magnetic measurements. This material exhibited magnetic behavior and porosity. The results show that porous ferromagnetic glass-ceramic, which saturation magnetization (Ms) of about 25 A·m2/kg and diameter of porous 30-50μm, was obtained.
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Authors: A. Lukawska, Z. Jagoo, Gregory Kozlowski, Z. Turgut, H. Kosai, A. Sheets, T. Bixel, A. Wheatley, P. Abdulkin, B. Knappett, T. Houlding, V. Degirmenci
Abstract: AC magnetic heating of superparamagnetic Co and Fe nanoparticles for application in hyperthermia was measured to find a size of nanoparticles that would result in an optimal heating for given amplitude and frequency of ac externally applied magnetic field. To measure it, a custom-made power supply connected to a 20-turn insulated copper coil in the shape of a spiral solenoid cooled with water was used. A fiber-optic temperature sensor has been used to measure the temperature with an accuracy of 0.0001 K. The magnetic field with magnitude of 20.6 μT and a frequency of oscillation equal to 348 kHz was generated inside the coil to heat magnetic nanoparticles. The maximum specific power loss or the highest heating rate for Co magnetic nanoparticles was achieved for nanoparticles of 8.2 nm in diameter. The maximum heating rate for coated Fe was found for nanoparticles with diameter of 18.61 nm.
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Authors: E.M. Múzquiz-Ramos, Dora A. Cortés-Hernández, C.G. Sánchez-Torres, José C. Escobedo-Bocardo, A. Zugasti, X.S. Ramírez-Gómez
Abstract: The aim of this work was the synthesis of bioactive magnetic particles (BMP) which are expected to form a thin apatite layer on its surface that may bond to bone with the osseous carcinogen tissue. Magnetite and Mg0.6Ca0.4Fe2O4 nanoparticles were obtained by a reverse co-precipitation and sol-gel methods, respectively. Magnetite particles were coated with chitosan in order to obtain a stable ferrofluid. Then both ferrites were biomimetically treated using two different simulated body fluids (SBF and 1.5 SBF). An apatite layer was formed on both types of BMP after the biomimetic treatment. Both ferrites showed superparamagnetic behavior before and after the apatite formation. Their time-dependent temperature profiles were measured under the effect of an AC magnetic field (AMF). After less than 20 min of applying the AMF an appropriate temperature for hyperthermia treatment was obtained. No citotoxicity was observed after osteosarcoma cell culture testing of BMP. Furthermore, after applying an AMF to the cells in contact with the BMP, the cells viability decreased considerably.
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Authors: K.M. Spiers, J.D. Cashion, Kārlis A. Gross
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Authors: Y. Kuwahara, Toshiki Miyazaki, Kawashita Masakazu
Abstract: This study is concerning hybrid materials composed of the magnetite and the organic polymer such as dextran. They are useful for hyperthermia of cancer. In the preparation of this material, chemical structure or molecular weight of the added polymer is expected to affect ionic interaction between polymer and iron salts, and consequently the grain size and morphology of the prepared magnetite core. Therefore, we have synthesized magnetite-polymer hybrids using various polymers. Various polymers were dissolved in iron (II) chloride aqueous solution, and then NaOH aqueous solution was added to this mixed solution. As a result, in the case of neutral and cationic polymer crystalline magnetite was precipitated in the hybrid. On the other hand, in the case of anionic polyacrylic acid, lepidocrocite was precipitated rather than magnetite. It is known that the magnetite formation progresses through intermediate Fe (OH)2 formation and oxidation of the Fe (OH)2 by dissolved O2. Therefore it is considered that tight ionic interaction is constructed between the iron ions and the carboxyl group in the polyacrylic acid to form a complex, and the Fe (OH)2 formation is inhibited. When the hybrid was prepared by addition of NaOH aqueous solution to iron (II) chloride solution, and subsequent addition of the different polymers, magnetite formation was not inhibited irrespective of kind of polymer. The present results indicate that crystalline structure of the magnetite phase in magnetite-polymer hybrid is strongly affected by the chemical structure of polymer additives or the order of addition.
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Authors: Thosdeekoraphat Thanaset, Santalunai Samran, Thongsopa Chanchai
Abstract: The performance improved of focusing deep hyperthermia inductive heating for breast cancer treatment using magnetic fluid nanoparticles with magnetic shielding system has been presented in the paper and the results are discussed. It is a technique challenge in hyperthermia therapy is to control locally heat the tumor region up to an appropriate temperature to destroy cancerous cells, without damaging the surrounding healthy tissue by using magnetic fluid nanoparticles and cylindrical metal shielding with aperture. We show that the magnetic field intensity can be controlled by changing the aperture size to suitable. In addition, the position of the heating can be controlled very well with the magnetic fluid together with shielding system. In the simulation, the inductive applicator is a ferrite core with diameter of 7 cm and excited by 4 MHz signal. Results have shown that the temperature increments depend on the magnetic fluid nanoparticles. In addition, the magnetic field intensity without damaging the surrounding healthy tissue when used magnetic shielded system. These results demonstrate that it is possible to achieve higher temperatures and to focus magnetic field intensity where the nanoparticles and magnetic shielding system are used.
353
Authors: D.H. Kim, Se Ho Lee, Kyoung Nam Kim, Kwang Mahn Kim, I.B. Shim, Yong Keun Lee
Abstract: Ceramic ferrites can be used to cancer-treatment. Heating of certain organs or tissue up to temperature between 42oC and 45oC preferentially for cancer therapy is called hyperthermia. We synthesized ferrites with various compositions in the system Co1-xNixFe2O4 as hyperthermic thermoseed in cancer-treatment and evaluated their effects on the necrosis of cancer cells under alternating magnetic field in vivo as well as in vitro. When a CoFe2O4 was placed into 0.2 ml distilled water, the greatest temperature change in this study, Δ T=29.3oC, was observed. More than half of the carcinoma cells were dead after exposure to alternating magnetic field using CoFe2O4, while normal cells were survived more than 60%. The injection of this ferrite particles into the tumor bearing mice was able to suppress the number and volume of tumors. CoFe2O4 is expected the useful hyperthermic thermoseed in cancer-treatment because it exhibited the greatest necrosis of carcinoma cells in vitro and in vivo.
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Authors: Cheng Li, Dong Lin Zhao, Fei Fei Sun, Xia Jun Wang, Ran Ran Yao
Abstract: The superparamagnetic graphene nanosheets–Fe3O4 nanoparticles (GNs–Fe3O4) hybrid has been successfully prepared via an easy and scalable chemical precipitation method. The inductive heat property of GNs–Fe3O4 hybrid in an alternating current (AC) magnetic field was investigated. The potential of GNs–Fe3O4 hybrid was evaluated for localized hyperthermia treatment of cancers. The GNs–Fe3O4 hybrid exhibits a superparamagnetic behavior, its specific saturation magnetization, Ms is 66.963 emu g-1. After exposed in the AC magnetic field for 1140 sec, the temperature of physiological saline suspension containing GNS–Fe3O4 hybrid were 81 oC. The GNs–Fe3O4 hybrid will be useful as good thermoseeds for localized hyperthermia treatment of cancers.
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Authors: Kwo Ping Chang, Ching Han Cheng, Ying Chi Chiang, Shan Chih Lee, Chih Yuan Lin, Bor Tsung Hsieh, Ching Chio Ko, Ya Ling Huang
Abstract: Hyperthermia using ferrofluid with alternating current (AC) magnetic field, which is the principal method we try to use in this study, where chitosan was used as a surfactant agent. Irradiation of Co-60 plays multi-function roles on the syntheses of chitosan-coated nanoparticles. Optimal conditions for synthesizing magnetic nanoparticles have been successfully found by the Taguchi method in which the dominated quality characteristic was SAR.
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Authors: Bao Qiang Li, De Chang Jia, Yu Zhou, Qiao Ling Hu, Wei Cai
Abstract: Magnetic hydroxyapatite/chitosan nanocomposites were prepared via in situ hybridization strategy in the ambient condition. Magnetic hydroxyapatite/chitosan nanocomposites were investigated by XRD, SQUID and TEM. XRD results indicated that the inorganic phases dispersed in chitosan matrix were composed of magnetite and hydroxyapatite. The magnetic hydroxyapatite/chitosan shown the behavior of superparamagnetism determined by SQUID, which indicated the size of magnetite crystal were less than 30nm. The inorganic nanoparticles with size of 30-50nm were dispersed chitosan matrix homogeneously. In situ hybridization strategy provided a simple and efficient route to synthesize the magnetic chitosan/hydroxyapatite nanocomposites in the mild condition. The most important of in situ hybridization is that the processes of precipitation of chitosan, synthesis of magnetite and hydroxyapatite, and compositing between three components were completed in single step.
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