Papers by Keyword: Hyperthermia

Abstract: Magnetic nanoparticles (Fe₃O₄) have considerable attention in various biomedical applications such as biosensors, drug delivery systems in the body, magnetic resonance imaging (MRI), and hyperthermia therapy. Hyperthermia therapy uses heat controlled by applied AC (Alternating Current) magnetic to kill cancer cells. This research aims to determine the effect of changes in temperature caused by the AC magnetic field on the varied magnetic nanoparticle solution. The Synthesize of Fe₃O₄ used the coprecipitation method to produce Fe₃O₄ nanoparticles. Mass of Fe₃O₄ nanoparticles varied of 95 mg and 125 mg. Nanoparticles physical properties were characterized using X-ray diffraction (XRD), Scanning Electron Microscope (SEM), and vibrating sample magnetometer (VSM). XRD profiles indicated that magnetic (Fe₃O₄) nanoparticles were successfully synthesized with a crystal size of 7.76 nm. SEM characterization of Fe₃O₄ nanoparticles was carried out at a magnification of 150.000 times and the average diameter of Fe₃O₄ powder nanoparticles was 20 nm. The temperature change measurement was performed using an AC magnetic field of 2.8 mT and frequency of 343 Hz, and time recorded changes temperature in 660 seconds. The temperature changes for solution concentrations of 95 mg and 125 mg were 7.7°C and 9.8°C, respectively. the concentration of solutions affects the value of the Specific Absorption Rate (SAR). The SAR values of each concentration of Fe₃O₄ solution were 0,0069 W/g and 0.0096 W/g. It proves that Fe₃O₃ prepared by coprecipitation method has potential for hyperthermia therapy application.

Abstract: Magnetic nanoparticles (MNPs) have many uses for biomedical applications including drug delivery, magnetic resonance imaging (MRI) contrast agents, theranostics and hyperthermia. MNPs photo-thermally heated by laser light could be used to treat the typically difficult to access tumors such as glioblastomas. Due to their high magnetic saturation, monometallic iron nanoparticles would have an edge over iron oxide nanoparticles currently being investigated for hyperthermia. The goal of this study was to synthesize spherical iron nanoparticles less than 10 nm in diameter by thermal decomposition. The ability of various biocompatible coatings to protect the metallic iron nanoparticles from oxidation was investigated. Coatings studied included Brij, polyethylene glycol and iron oxide. Transmission electron microscopy and Mössbauer spectroscopy were utilized to characterize the coated and uncoated iron nanoparticles’ size and oxidation state to evaluate the effectiveness of the coatings and the procedures in which the coatings were applied. A ferrite shell was found to provide the best stabilization; however, its longer synthesis time increased particle size distribution. Polymer coatings provided biocompatibility but did not prevent oxidation.

Abstract: The recent development of the using the magnetic nanoparticles for hyperthermia treatments emphasizes the needed of smart materials to become a safety for heat therapy. Self-regulate magnetic nanoparticles of MnZnFe₂O₄ may be proper for thermal treatments. Structure and magnetic properties of the synthesis Mn_1-xZn_x Fe₂O₄ with x=0- 0.5 by step 0.1were studied. Superparamagnetic nanoparticles of MnZnFe₂O₄ were prepared by co-precipitation method, followed that heat treatment in the autoclave reactor. XRD results showed that is difficult to prepare MnZnFe₂O₄ directly using the co-precipitation method. Preparation method yield nanoparticles with spherical shape and there is a slight change in the particle size distribution, also observed shrinkage occurs in the particle size after heat treatments, the average particle size was estimated about 20nm as confirmed by FESEM images. FTIR spectra of samples showed two distinct absorption peaks in the range ~ 617 – 426 (cm^-1) related to stretching vibrations of the (Fe-O) in the tetrahedral and octahedral side respectively. Magnetic measurements were carried out using (VSM), M-H curves indicate typical soft magnetic materials and particles so small to be identical superparamagnetic nanoparticles. Heating ability of water based colloidal dispersions of samples were studied under magnetic field strength 6.5kA/m and the frequency 190 kHz, and the results showed when increasing Zn²⁺ to x=0.3 or more the samples not heated up. Depending on the heating curve susceptibility, effective relaxation time 𝜏 and Néel relaxation time , were determined.

Abstract: In recent time, interest to ferrite magnetic nanomaterials has considerably grown mainly due to their much promising medical and biological applications. The spinel ferrite powder samples having high heat generation ability in AC magnetic field was studied for application to hyperthermia treatment of cancer tumor. These properties of ferrites are strongly depending on their chemical composition, ion distribution, spin orientation and method of preparation in general and crystal structure in particular nature of the material. In this study, several samples of ferrite magnetic structures were investigated by neutron diffraction. The explanation of the mechanism to occurs the heat generation ability in the magnetic materials and the electronic and magnetic states of ferrite-spinel – type structures were theoretically defined by the first-principles calculations within the framework of DFT.

Abstract: The functionalization of superparamagnetic iron oxide (SPIO) nanoparticles with bioactive molecules enables new applications of these nanomaterials due to their magnetic properties, which is affected by the surface coating of the nanoparticles. In this work, Fe₃O₄ nanoparticles type / core layer were synthesized by co-precipitation wet method and coated with a polymer mixture of polyethylene glycol (PEG). It was performed a study about duration in encapsulation of nanoparticles in their final size in order to get different thickness of coated layer and varied coating properties. With this study was expected to obtain different thicknesses and thus the coating properties. Five samples were synthesized according to the same procedure and amount of reactants used synthetic sequence for all samples, only varying the time spent by each sample coating process with polyethylene glycol. The different times for the coating samples were 10 minutes, 20 minutes, 30 minutes, 50 minutes and finally 60 minutes. The nanoparticles were characterized by Nanosight, TGA and DSC techniques. The results showed that the particle size suffers an increase during the first 30 minutes of duration of the coating step and then stabilizes.

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.

Abstract: Structural and magnetic characteristics of (La,Sr)MnO₃ nanoparticles synthesized by different methods have been studied in the work. The specific loss power which is released on the exposure of an ensemble of synthesized particles to alternating magnetic field was calculated and measured experimentally. The contributions to the specific loss power resulted from different heating mechanisms have been discussed. The directions to enhance the heating efficiency of various kinds of magnetic nanoparticles are outlined

Abstract: Three types of ferromagnetic nanostructures based on barium hexaferrite (BaFe₁₂O₁₉), lanthanum-strontium manganites with perovskite structure ((La,Sr)MnO₃) and materials with spinel structure (AFe₂O₄, A = Ni, Zn, Co, Mn, Fe) have been synthesized by precipitation from aqueous and nonaqueous solutions, by the sol-gel method and from microemulsions. Magnetic properties of the synthesized nanoparticles and films have been investigated. It was shown that the obtained nanoparticles exhibit superparamagnetic properties. It has been found that the synthesized nanoparticles have promise in hyperthermia of cancer cells. It has been shown that the films based on barium hexaferrite can have promise in the creation of nonlinear resonant microwave elements on the basis of high-Q dielectric resonators and ferromagnetic films.

Abstract: Nowadays, superparamagnetic iron oxide nanoparticles are an important tool for cancer treatment, such as magnetic hyperthermia. The goal is heating diseased tissue and then tumor cells are destroyed. Magnetic nanoparticles are promising mainly because they have specific ability to reduce side effects. However, for in vivo applications, nanoparticles need to be coated by a biocompatible material. In this work, nanoparticles are coated by PEG (biocompatible polymer). Samples were produced by coprecipitation process. Information about particle size, magnetic properties and crystallinity were obtained.

Abstract: Malignant tumors are caused by uncontrolled multiplication of cells in the body. It is possible to stop the growth of atypical cells by overheating (hyperthermia). By the magnetization process of magnetite nanoparticles, energy is dissipated as heat (Joule effect), producing increase of temperature. This causes the rupture of cancer cells. In this work, magnetic nanoparticles were synthesized by coprecipitation method and coated by biocompatible material (chitosan or castor oil). The samples showed required characteristics of nanocrystallinity, superparamagnetism and biocompatibility. This was deduced from hysteresis curve, thermal analysis and X-ray Diffraction data. Thus, the nanocomposite exhibits excellent features for use in vivo.