Summary of Chemistry doctoral thesis: Synthesis and properties of ferrite - metal (Ag, Au) hybrid nanostructures for biomedical application

This work aims to fabricate ferrite - (Ag, Au) hybrid nanomaterials with a SPR peak located in the near-infrared region, high magnetic/optical-to-thermal conversion and ability to contrast MRI images for both T1- and T2- weighted modes, which are strongly bactericidal and able to be applied in biomedicine.
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Summary of Chemistry doctoral thesis: Synthesis and properties of ferrite - metal (Ag, Au) hybrid nanostructures for biomedical application MINISTRY OF VIETNAM ACADEMY OF EDUCATION AND TRAINING SCIENCE AND TECHNOLOGY GRADUATE UNIVERSITY SCIENCE AND TECHNOLOGY _________________________________________ NGUYEN THI NGOC LINH SYNTHESIS AND PROPERTIES OF FERRITE - METAL (Ag, Au) HYBRID NANOSTRUCTURES FOR BIOMEDICAL APPLICATION Major: Inorganic chemistry Code: 9.44.01.13 SUMMARY OF CHEMISTRY DOCTORAL THESIS Ha Noi - 2020 This thesis was done at: Laboratory of Electronic-Electrical Engineering, Institute for tropical technology, Vietnam Academy of Science and Technology. Laboratory of Biomedical Nanomaterials, Institute of Materials and Science, Vietnam Academy of Science and Technology. Supervisor 1: PhD. Le Trong Lu Supervisor 2: Assoc.Prof., PhD. Ngo Dai Quang Reviewer 1: Prof., PhD. Thai Hoang Reviewer 2: Assoc.Prof., PhD. Huynh Dang Chinh Reviewer 3: Assoc.Prof., PhD. Nguyen Thi Hien Lan The dissertation will be defended at Graduate University of Science and Technology, 18 Hoang Quoc Viet street, Hanoi. Time: .............,.............., 2020 This thesis could be found at National Library of Vietnam, Library of Graduate University of Science and Technology, Library of Vietnam Academy of Science and Technology. INTRODUCTION 1. The necessary of the thesis In recent years, hybrid nanomaterials have attracted the attention of many researchers due to their integrated properties from individual components. The combination of magnetic and optical properties on a nanostructure has improved the application of single nanoparticles (NPs) and opened new directions in biomedical applications, especially in diagnosis and treatment. The advantage of magneto- plasmonic hybrid nanostructures in this area is that the desired target has merely been achieved after being activated by a physical stimulus, thus minimizing damaging effects on body. Furthermore, several functions can work synergically to enhance the efficiency in therapeutic methods. Currently, many magneto-plasmonic hybrid nanostructures have been studied in order to apply in the biomedical field in which Fe3O4/Au material has been one of the most typical materials. The studies on Fe3O4/Au hybrid NPs for magnetic resonance imaging (MRI) and magneto-photothermal therapy in cancer treatment have obtained some remarkable results. However, Fe3O4@Au core-shell hybrid NPs with Au layer coated on the surface of Fe 3O4 core significantly limit the connection of protons to the magnetic materials, leading to the reduction of the T2-weighted MRI contrast signal. In addition, Fe3O4-Au hybrid NPs exhibit the surface plasmon resonance (SPR) position in the range from 530 to 600 nm, limiting the deep penetration into thick tissue layers and reducing the efficiency of the photothermal therapy. In order to improve the effectiveness of the thermal therapy, the materials have to absorb radiation in near-infrared (NIR) region (650 ÷ 950 nm), also known as biological windows” region, because the NIR radiation has the highest ability to penetrate the body. The previously fabricated hollow Fe3O4/Au hybrid NPs can meet this criterion, however, their large size (40 ÷ 100 nm) impact the blood circulation. Therefore the fabrication of the hollow Fe3O4/Au hybrid NPs with particle size 1 below 20 nm and the integration of both magnetic and plasmonic properties is still a big challenge. In Vietnam, to our best knowledge, the publication of the fabrication of the magnetic – noble metals hybrid nanomaterials (Ag, Au) integrated magnetic and plasmonic properties, which can be applied in the biomedical field, is still limited. Research that results on the application of Fe3O4-(Ag, Au) hybrid NPs as MRI contrast agents under both T1- and T2-weighted modes, and as a heat (optical/magnetic-thermal) substance in cancer treatment has not been reported. For these reasons, we conduct the thesis on topic “Synthesis and properties of ferrite - metal (Ag, Au) hybrid nanostructures for biomedical application”. 2. Research objectives of the thesis This work aims to fabricate ferrite - (Ag, Au) hybrid nanomaterials with a SPR peak located in the near-infrared region, high magnetic/optical-to-thermal conversion and ability to contrast MRI images for both T1- and T2- weighted modes, which are strongly bactericidal and able to be applied in biomedicine. 3. The main research contents of the thesis 1. Synthesis of magnetic ferrite nanoparticles MFe2O4 (M: Fe, Co, Mn) with uniform size and shape, monodisperse, and high saturation magnetization using thermal decomposition method in organic solvents. 2. Synthesis of small Fe3O4/Ag hybrid particles (below 20 nm) by seeded-growth method, and synthesis of Fe3O4/Au hollow hybrid nanoparticles with size below 20 nm and NIR light absorption by using Fe3O4/Ag nanoparticles as template via Galvanic replacement approach in organic solvents. 3. Phase transfer of the as-synthesized NPs from organic solvent to aqueous solvent, and evaluation of toxicity and durability of the hybrid particles in aqueous water. 4. Study on the applicability of the hybrid particle solution in biomedical: antibacterial activity, ability to convert optical/magnetic energy into heat, and the ability to contrast MRI images. 2 CHAPTER 1. OVERVIEW ABOUT MAGNETIC FERRITE - NOBLE METAL NANOMATERIALS 1.1. General introduction of magnetic ferrite - noble metal nanomaterials 1.1.1. Magnetic properties of magnetic ferrite materials The magnetic properties of materials var ...