Study on the fabrication of magnetic fluids based on superparamagnetic iron oxide nanoparticles (spions) applied to magentic resonance imaging (mri) application

Recent applications of magnetic nanoparticles in biomedical applications, especially in imaging diagnostics using MRI Magnetic Resonance Imaging engineering have attracted the attention of scientists around the world. Currently in imaging diagnostics using MRI magnetic resonance imaging, Tl contrast agents have become a traditional commodity, which is a complex of paramagnetic ions with a large torque value like Gd3+ (7 unpaired electrons). These Gd3+ ions are combined with molecules such as DTPA (diethylentriamine penta acetic acid) and create Gd-DTPA chelate round complex structures. During the recovery process, the interaction between the magnetic moment of the proton and the magnetic moment of the paramagnetic ions causes the T1 time to be reduced, so the recovery rate R1 increases. The concentration of agents is different in each cell tissue region, thus providing an effective contrasting on MRI images. For nearly 10 years now, along with the development of nanotechnology iron oxide (IO) nanoparticle having been strongly researched and actual many commercial products that increase MRI contrast levels using this iron oxide material, proving that iron oxides-MRI can give better quality of contrast level than Gd-DTPA because iron oxide particles have a higher magnetic induction coefficient. IO-MRI substances can reduce both T1 and T2, increasing MRI recovery rates in both Tl and T2 MRI modes. The important requirements for MRI contrast increasing products are that magnetic nanoparticles must have a relatively uniform particle distribution and magnetic saturation enough large, and the coating materials must have good biological compatibility. While some commercial products in the world, such as Resovist, use dextran as a coating material, with a 65 nm core particle created from saturation of about 65 emu/g. Products with particle sizes in the 20- 40nm region such as AMI-227: Sinerem/Combidex are suitable for lymph and bone. In the last 10 years, people have been studying to create superparamagnetic nanoparticles with a particle size smaller than 20 nm (also known as microscopic if the particle size is D<10 nm) and especially iron oxide particles, marked with magnetic markers is intended for MRI targeted imaging.

pdf28 trang | Chia sẻ: thientruc20 | Lượt xem: 553 | Lượt tải: 0download
Bạn đang xem trước 20 trang tài liệu Study on the fabrication of magnetic fluids based on superparamagnetic iron oxide nanoparticles (spions) applied to magentic resonance imaging (mri) application, để xem tài liệu hoàn chỉnh bạn click vào nút DOWNLOAD ở trên
MINISTRY OF EDUCATION AND TRAINING VIETNAM ACADEMY OF SCIENCE AND TECHNOLOGY GRADATE UNIVERSIY OF SCIENCE AND TECHNOLOGY  LE THE TAM STUDY ON THE FABRICATION OF MAGNETIC FLUIDS BASED ON SUPERPARAMAGNETIC IRON OXIDE NANOPARTICLES (SPIONs) APPLIED TO MAGENTIC RESONANCE IMAGING (MRI) APPLICATION Major: Inorganic chemistry Code: 9.44.01.13 SUMMARY OF CHEMISTRY DOCTORAL THESIS Ha Noi - 2019 This thesis was done at: Laboratory of Biomedical Nanomaterials, Institute of Materials and Sciene, Vietnam Academy of Science and Technology. Laboratory of Electronic-Electrical Engineering, Institute for tropical technology, Vietnam Academy of Science and Technology. Centre for Pratices and Experimences, Vinh University. Supervisor: Prof., Dr. Tran Dai Lam Assoc.Prof., Dr. Nguyen Hoa Du Reviewer 1: ..................................................... Reviewer 2: ..................................................... Reviewer 3: ..................................................... The dissertation will be defended at Graduate University of Science and Technology, 18 Hoang Quoc Viet street, Hanoi. Time: .............,.............., 2019 This thesis could be found at National Library of Vietnam, Library of Graduate University of Science and Technology, Library of Chemistry, Library of Vietnam Academy of Science and Technology. INTRODUCTION Recent applications of magnetic nanoparticles in biomedical applications, especially in imaging diagnostics using MRI Magnetic Resonance Imaging engineering have attracted the attention of scientists around the world. Currently in imaging diagnostics using MRI magnetic resonance imaging, Tl contrast agents have become a traditional commodity, which is a complex of paramagnetic ions with a large torque value like Gd3+ (7 unpaired electrons). These Gd3+ ions are combined with molecules such as DTPA (diethylentriamine penta acetic acid) and create Gd-DTPA chelate round complex structures. During the recovery process, the interaction between the magnetic moment of the proton and the magnetic moment of the paramagnetic ions causes the T1 time to be reduced, so the recovery rate R1 increases. The concentration of agents is different in each cell tissue region, thus providing an effective contrasting on MRI images. For nearly 10 years now, along with the development of nanotechnology iron oxide (IO) nanoparticle having been strongly researched and actual many commercial products that increase MRI contrast levels using this iron oxide material, proving that iron oxides-MRI can give better quality of contrast level than Gd-DTPA because iron oxide particles have a higher magnetic induction coefficient. IO-MRI substances can reduce both T1 and T2, increasing MRI recovery rates in both Tl and T2 MRI modes. The important requirements for MRI contrast increasing products are that magnetic nanoparticles must have a relatively uniform particle distribution and magnetic saturation enough large, and the coating materials must have good biological compatibility. While some commercial products in the world, such as Resovist, use dextran as a coating material, with a 65 nm core particle created from saturation of about 65 emu/g. Products with particle sizes in the 20- 40nm region such as AMI-227: Sinerem/Combidex are suitable for lymph and bone. In the last 10 years, people have been studying to create superparamagnetic nanoparticles with a particle size smaller than 20 nm (also known as microscopic if the particle size is D<10 nm) and especially iron oxide particles, marked with magnetic markers is intended for MRI targeted imaging. In Vietnam, up to now the fabrication of nanoparticles in general and magnetic nanoparticles in particular has been focused to research in accordance with two aspects: basic research and application-orientation research. The profound research results are published mainly from large research institutions such as: Hanoi National University, Hanoi University of Science and Technology and Vietnam Academy of Science and Technology. The synthesis of magnetic nanomaterials is mostly carried out in water and by synthetic methods such as co-precipitation methods, hydrothermal methods, microwave methods and ultrasonic electrochemical synthesis methods. Due to the synthesis in the water environment, the fabricated magnetic nanoparticles have not high quality, the particles are uneven in size and heterogeneous in shape and therefore they are restricted for use in vivo printing applications in biomedicine such as used as a contrast drug in imaging diagnosis by MRI magnetic resonance imaging, magnetic induction heating, etc. in addition, the such unevenness even affects the research results of their magnetic properties. Therefore, up to now, the selection of conditions in the fabrication of Fe3O4 nano magnetic fluid to produce particles with small particle size, uniform distribution, homogeneous shape and high durability, high magnetism and high biocompatibility, thus making it possible to apply as contrast medicine in imaging diagnostics using MRI magnetic resonance imaging, creating optimal values of impulses TR, TE when taking with T1, T2 mode, and determining recovery coefficient r1, r2 to assess the quality of magnetic fluids as contrast medicine in imaging diagnosis by MRI magnetic resonance imaging is still asking for continuing and systematic research. Derived from the research on nanomaterials in the world as well as in Vietnam, based on the research and Doctor training potential of the Institute of Science and Technology, Vietnam Academy of Science and Technology, under the guidance of a group of experienced scientists, we select the topic "Study on the fabrication of magnetic fluids based on superparamagnetic iron oxide nanoparticles (SPIONs) applied to magentic resonance imaging (MRI) application" to make this thesis content. Research object of the thesis: Magnetic fluid system based on superparamagnetic iron oxide. Research targets of the thesis: The goad of the thesis is to build the manufacture process of nano-sized magnetic fluids based on iron oxide (uniform particle size and high magnetic saturation) with stable technology; Characteristic research of magnetic properties of magnetic nanoparticles; assessment of toxicity and test of effects on cells, aiming to make contrast medicine in imaging diagnosis by magnetic resonance imaging (MRI), application on accurately identifying cancer. Scientific and practical meaning of the thesis: The implementation organization of the topic itself has important implications for developing a multi-disciplinary science and technology direction as Nanotechnology for Medicine. There will be academic exchange, mutual learning between research groups in the industries deem as independent. Scientifically, the magnetization of magnetic particle systems for biomedical applications is strongly influenced by many factors, but the mechanism of these effects is still a problem that has not been studied fundamentally. For the application of cancer diagnosis and treatment, nanotechnology in general is creating a great expectation that is able to contribute to solve the problem of early disease diagnosis and drugs to target or intervention areas localized at the destination. The subject has a goal of using magnetic fluid improving the contrast of nuclear magnetic resonance imaging (MRI), which can contribute to the analysis of early-stage cancer tissue. Research methodology: The thesis is conducted by experimental method combined with numerical calculation techniques. The research sample is fabricated by hydrothermal and thermal decomposition methods. Study the structure of the sample by X-ray diffraction techniques (XRD), electron microscopy (FESEM, TEM and HRTEM). The magnetic properties of the materials are surveyed by magnetic measurements on the vibrating sample magnetometer (VSM) system. Using Fourrier Transformation InfraRed (FTIR), Thermal gravimetric analysis (TGA) to evaluate the presence of functional groups on the particle surface and the mass reduction of polymer-coated magnetic particle layer. Dynamic Light Scattering (DLS) technique determines the hydrodynamic size and durability of magnetic fluids. Experimental assessment of toxicity through in-vitro test. MRI imaging method T1, T2 for studies of contrast enhancement of material samples for manufacturing (on 1.5T MRI scanner, SIEMENS MAGNETOM, Germany). Research contents of the thesis: 1. Successful summary of Fe3O4 magnetic nanoparticles with uniform particle size and high saturation magnetization by hydrothermal and thermal decomposition methods. 2. Successfully fabrication of high-strength magnetic fluids on Fe3O4 particles synthesized by the above two methods. 3. Research on the toxicity and durability of magnetic fluids. 4. Study the applicability of image contrast enhancer in MRI magnetic resonance imaging. The layout of the thesis: The thesis has 137 pages (not including references, appendices), including the introduction, 5 chapters of content and conclusions. The main results of the thesis are published in 09 published projects, including 01 article published under SCI list, 01 article sent from SCI list submitted and reviewing, 05 articles on National magazine, 01 article published in the Proceedings of the National Science Conference, and registered 01 intellectual property (SC) has been published in the volume A Industrial Ownership Gazette. Main results of the thesis: The influence and optimization of technological conditions on the structure and magnetic properties of chitosan-coated Fe3O4 nanoparticles (CS) were investigated using hydrothermal method. Successfully fabricated magnetic fluids based on Fe3O4 particles by thermal decomposition method by phase transformation and coating by polymer PMAO. Fe3O4@PMAO liquid samples are highly durable in different conditions, single-dispersed, uniform particles. Evaluation of the toxicity of magnetic fluids on typical samples with different cell lines, results are good IC50 index. Manufactured fluid Samples are not cytotoxic, which is the basis for conducting subsequent experiments on animals. Determined the relaxation rate of nuclear magnetic resonance imaging (MRI) of 2 systems Fe3O4@CS, Fe3O4@PMAO showed that the uniform fabrication systems have high r2 values of over 150 mM-1s-1 for samples of Fe3O4@PMAO, higher than commercial products Resovist. These substances, when given MRI imaging tests, show good potential for applications to increase contrast. In vitro, ex-vivo and in-vivo studies of MRI contrast enhancement showed that many of the magnetic fluids of the manufacturing subject group exhibited good contrast enhancement. Applying the Fe3O4@PMAO system to solid tumors under the skin and liver tumors, shows the potential for observing the detailed shape and structure of the tumor, supporting diagnosis and treatment. CHAPTER 2. REVIEW OF SPINEL FERRITE MATERIAL AND MAGNETIC RESONANCE IMAGING METHOD BY MRI SHOOTING ENGINEERING 1.1. The structure and magnetic properties of spinel ferrite materials 1.1.1. Structure of spinel ferrite Ferrite spinel is the term used to refer to a material with a two-subnetwork structure of which interactions are antiferromagnetic or magnetic ferrite. A basic cell unit of spinel ferrite (with crystal lattice constant a ~ 8.4 nm) is formed by 32 atoms O2- and 24 cation (Fe2+, Zn2+, Co2+, Mn2+, Ni2+, Mg2+, Fe3+ và Gd3+). In a base cell there are 96 positions for cations (64 in octahedral position, 32 in tetrahedral position). The number of cations is more octahedral in the tetrahedral position (A), in particular there are 16 cations occupied in the octahedral position (B) while in the tetrahedral position there are only 8 cations (including valency cation 2+ or 3+). 1.1.2. Magnetic properties of spinel ferrite materials According to molecular field theory, the magnetic origin in spinel ferrite materials is due to the indirect exchange interaction between metal ions (magnetic ions) in two subnetworks A and B through oxygen ions. 1.1.3. Magnetism of nanometer-sized particle magnetic materials The superparamagnetic phenomenon (or status) occurs for ferromagnetic materials composed of small crystalline particles. When the particle size is large, the system will be in the multidomain state (i.e. each particle will be composed of many magnedomain particles). When the particle size decreases, the substance will turn into a mono-state, which means that each particle will be a dime. When the particle size decreases too small, the directional energy (which predominantly dominates are that the crystal magnetic anisotropic energy is much smaller than the thermal energy, then the thermal energy will break the parallel orientation of magnetic moments) and then the magnetic moment of the particle system will orient chaotically as in paramagnetic material. 1.2. The studying situation of nanomaterials in the domestic and abroad In Vietnam, a number of research groups at the Institute of Materials Science, International Training Institute for Materials Science - Hanoi University of Science and Technology and Hanoi National University (VNU) have also announced their manufacture of magnetic nanoparticles for biomedical applications and for basic research. 1.3 . Manufacture methods of magnetic fluids 1.3.1. Synthesizing methods of magnetic nanomaterials For biomedical applications, the material is often made by a number of chemical methods such as co-precipitation, solgel, microemulsion, hydrothermal, thermal decomposition, microstorage, etc. Chemical methods can create nanoparticles with a quite high uniformity and facilitate to be able to coat particles and transfer phase of the particles from oil to water. Each of the above methods has different characteristics. 1.3.2. Particle coating technologies in water solvent For nanoparticles synthesized by chemical methods in water solvents, the coating of the particles or the functionalization of the nanoparticle surface after fabrication is a very important factor to ensure both magnetic properties and biological compatibility. When the surface is coated and functionalized, the nanoparticles easily disperse in a suitable solvent and become homogeneous colloidal particles called magnetic fluids. 1.3.3. The process to transfer the phase from organic solvents to water solvents In order to obtain high-quality magnetic nanoparticles, sample fabrication is usually carried out in organic solvents at high boiling temperatures such as: benzyl ther, phenyl ether, octadecene...Therefore, before being able to be used in Biomedical, these magnetic nanoparticles need to be transferred from organic solvents to water solvents through phase transfer processes. 1.4. Application of magnetic nanoparticle systems in biomedical Magnetic nanoparticles have the potential to be applied in many different fields. In biomedical, magnetic nanoparticles can be used to extract biological molecules using magnetism, nano curcumin, and substances increasing contrast in magnetic resonance imaging (MRI) and magnetic burning application for cancer treatment. However, this thesis focuses on researching magnetic nanoparticle application orientation Fe3O4 to enhance nuclear magnetic resonance imaging (MRI) affect. CHAPTER 2. EXPERIMENTAL ENGINEERING 2.1. Summary of magnetic fluid system Fe3O4@CS by hydrothermal method Magnetic nanoparticles Fe3O4@CS is synthesized by hydrothermal method according to Figure 2.1 diagram. Figure 2.1. Fabrication process of magnetic fluids Fe3O4@CS. 2.2. Summary of nanoparticle system Fe3O4@OA/OLA by thermal decomposition method Nanoparticle system Fe3O4@OA/OLA is synthesized by thermal decomposition method according to Figure 2.2 diagram. Figure 2.2. Fabrication process of magnetic nanoparticles Fe3O4@OA/OLA. 2.3. Transfer the phase of nanoparticles slowly from organic solvents to water solvents The phase transfer process of magnetic nanoparticles from organic solvent to water is carried out according to the diagram of Figure 2.3. F e 3 O 4 F e 3 O 4 F e 3 O 4 Figure 2.3. PMAO encapsulation process. 2.3. Typical methods Study the structure of the sample by X-ray diffraction techniques, electron microscopy. Magnetic properties are surveyed by magnetic measurements on vibrating sample magnetometer system. Using infrared absorption spectra, weight analysis to assess the presence of functional groups on the particle surface and the mass reduction of the magnetic particle-coated polymer layer. Dynamic laser scattering technique determines the hydrodynamic size and durability of magnetic fluids. 2.4. Experimental planning method In experimental chemical and chemical technology studies, there are many experimental problems described as extreme problems: determining the optimal conditions of the process, the optimal composition of the mixture... Experimental planning allows to simultaneously change all the factors that affect the process and allow quantitative evaluation of basic effects and simultaneous interaction effects of the elements, thereby optimizing chemical technologies. 2.5. Evaluate the toxicity of fluids from cancer cells Evaluate potentially lethal the cancer cells and healthy cells and intact cells of fabricated magnetic fluid. 2.6. Testing the ability to contrast agent in MRI imaging techniques MRI imaging experiment in T1, T2 is used for the researches of image contrast enhancement of images of manufacturing materials (on 1.5T MRI scanner, SIEMENS MAGNETOM, Germany). CHAPTER 3. RESEARCH MAGNETIC FLUID BASED ON MAGNETIC IRON OXIDE SYTHETISED BY HYDROTHERMAL METHOD 3.1. Implement the optimal three-level quadratic experimental planning Table 3.1. Levels of independent variables and experimental conditions Run Variable levels Temperature 0C Time (h) Concentration Fe3+ (M) Ms (emu/g) A B C 1 + + - 180 4,00 0,1 34,73 2 + - + 180 2,00 0,25 53,22 3 - + + 120 4,00 0,25 61,89 4 - - - 120 2,00 0,10 57,26 5 -1,414 0 0 107,57 3,00 0,17 55,38 6 1,414 0 0 192,43 3,00 0,17 63,21 7 0 -1,414 0 150 1,59 0,17 61,4 8 0 1,414 0 150 4,41 0,17 60,07 9 0 0 -1,414 150 3,00 0,07 46,67 10 0 0 1,414 150 3,00 0,28 59,96 11 0 0 0 150 3,00 0,17 66,67 12 0 0 0 150 3,00 0,17 63,32 13 0 0 0 150 3,00 0,17 64,68 Factor Giá trị F p -value prob > F Model 35.75 0,0068a A 10.64 0,0038a B 7.31 0,0457b C 30.64 0,0116b AB 9.27 0,0308b AC 76,96 0,0031a BC 5,83 0,0346b A2 33,46 0,0103b B2 21,85 0,0185b C2 107,69 0,0019a R2=0,9908 Figure 3.2. Analysis of variance (ANOVA) for full quadratic model and Model coefficient estimated by linear regression (asignificant at 1% level; bSignificant at 5% level). Figure 3.3. Surface plot and contour plot of the combined effects of A and B (a); A and C (b) on the yield of Ms at another coded level of zero 0 0.01 0.02 0.03 0.04 0.05 B A C A B B 2 C A 2 A B C C 2 p -v al u e Variable The suitability analysis of the model and the significance of the model assessed by ANOVA analysis (Figure 3.2) and correlation indicators. The significance of the regression coefficients is tested by standard F, with values p<0.05 indicating significant regression coefficients. Thus, in Figure 3.2 found that the value of "Model F-value" is 35.75, the model is completely statistically significant with 99.08% reliability. With all the factors of sample incubation temperature, time, Fe3+ con
Luận văn liên quan