الفهرس 
Chapter 1Only 14 pages are availabe for public view
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Abstract
Advancement in nanotechnology and chemistry allows us to functionalize nanoparticles whose sizes are comparable to biological organelles. These various nanoparticles can be used to improve the efficiency of cancer treatment mainly through three modalities.(1) - Detection and imaging of cancer cells.(2) - The utilization of nanoparticles themselves as a treatment.(3) - Delivery of chemotherapy agents by loading them with nanoparticles.Part One: Green synthesis of magnetic nanoparticles.The first part of this thesis reports a novel, safe nanotherapeutic agent as a substitutional for heparin. Heparin and its low molecular weight are anticoagulants that prevent the formation and extension of blood clots. However, these anticoagulant causes bleeding that takes longer to stop. Here, magnetic iron oxide (Fe3O4NPs) coated with green tea (GTPs) is used as a safe and effective nontherapeutic agent for blood clotting prevention. In this work, Magnetic iron oxide coated with green tea (GT@Fe3O4NPs) was successfully synthesized using a simple eco-friendly green method. Green tea is employed as a green reducing and stabilizing agent. We employed this method as a new low-cost and time-consuming route. Structural, blood biocompatibility, and anticoagulant properties of the (GT@Fe3O4NPs) were analyzed. These analyses showed that the particles were of uniform shapes and sizes of 25 - 36 nm with a coating of GTPs. The vibrating sample magnetometer (VSM) measurement demonstrated a saturation magnetization of 4.90 emu/g with negligible coercivity and retentiveness, indicating the superparamagnetic behavior of the GT@Fe3O4NPs at room temperature. The synthesized magnetic nanoparticles were highly stable and well-dispersed in an aqueous medium through their hydrophilic coating of GTPs. Cell viability and prothrombin time (PT) showed excellent blood compatibility in addition to promising anticoagulant ability, respectively. As a result, GT@Fe3O4NPs can compete with heparin either in hemodialysis or in the treatment of thromboembolic events as it can overcome related bleeding problems to a great extent. Part Two: Surface modification of magnetic nanoparticles for MRI imaging.The second part involves the synthesis and surface modification of iron oxide (Fe3O4) magnetic nanoparticles (MNPs) by polyethylene glycol (PEG), polyvinyl alcohol (PVA), poly(N-vinyl pyrrolidone) (PVP), and Oleic acid coatings templates and stabilizers to synthesis Fe3O4 nanoparticles through co-precipitation method. Physical, Magnetic, and Biological properties of bared Fe3O4 and the coated Fe3O4. The crystallite size of the nanoparticles varied with the different coatings. The PEG, PVP, PVA, and OA coating samples significantly affected the morphology of the MNPs, stabilized and reduced the particle size. The prepared coated Fe3O4 nanoparticles exhibited high saturation magnetization and superparamagnetic behavior which is a single domain behavior of the observed particles and prevents the coupling between the magnetic nanoparticles because of the coating around the nanoparticles. The cell viability assay exhibited good biocompatibility. The results revealed that the PVP-grafted MNPs have great potential as a T2 contrast agent in Magnetic resonance Imaging.Part Three: Synthesis and characterization of Cisplatin/Fe3O4@PEG6000/SmO2 MNPs for T1-T2 imaging and treatment of breast cancer.The final part of this thesis is focused on trying to synthesize dual mode (T1-T2) contrast agents targting breast cancer cells. Breast cancer (BC) is the most common cancer in women accounting for approximately 32.04 % of the reported malignancies among Egyptian women. Cisplatin is used for the treatment of BC; however, cisplatin not only affects cancer cells but also affects normal cells. Nanoparticles provide a new platform for drug delivery to cancer. The most of available MRI contrast agents are paramagnetic complexes, such as gadolinium complexes, which facilitate the spin-lattice relaxation of protons and result in a positive MR image (T1 -weighted images). Nevertheless, the resulting image has low resolution and quality. An alternative solution is the use of efficient contrast agents such as iron oxides, although the development of iron oxide NPs as T2 contrast agents has gained great success, such single-mode contrast agents are increasingly facing challenges arising from accurate imaging of small biological targets because of the negative contrast effect and magnetic susceptibility artifacts. Therefore, the development of T1 –T2 dual model contrast agents is highly attractive because two different T1 and T2 imaging modes can be selectively utilized to visualize different tissues and potentially give more accurate information, which offers non-invasive, high-resolution cell tracking ability and very efficient contrast agent using both T1 and T2 imaging for BC. In this study magnetic nanoparticles enhanced T1 and T2 Imaging will be used for simultaneous molecular imaging and cisplatin delivery for targeting breast cancer cells.