Study On Multifunctional Magnetic Nanoparticles In Nuclear Magnetic Resonance Imaging And Tumor Therapy

Cancer has threatened human life for a long period of time. Although current methods for cancer therapy, such as chemotherapy, radiotherapy, operative therapy, and photodynamic therapy, are useful under certain conditions, they can also cause patients to suffer or result in anaphylaxis. Hyperthermiatherapy of photothermal and magnetothermal therapy is another therapeutic method for cancer treatment in which the tissue is exposed to high temperature conditions to damage cancer cells or make them more sensitive to anti-cancer drugs/radiation. It results in fewer side effects than traditional cancer therapies. With the development of oncology, the treatment of cancer is now tending to combine more than one method to achive better effect. Besides, imaging diagnostic, especially MRI, has been emerging a powerful technology in assisting cancer therapy in terms of early detection and targeting therapy. For effective cancer therapy, the development of imaging diagnostic guided multifunctional agents which can combine more than one therapy methods is of great importance. This paper is mainly focused on the study and synthesis of multifunctional magnetic nanocomposites and their application on MRI and cancer therapy. The full text consists of four chapters.In the second chapter, we synthesized Co Fe2O4@Mn Fe2O4/polypyrrole nanocomposites and studied their applications in MRI and cancer thermal therapy. We first synthesized Co Fe2O4 nanoparticles and then Co Fe2O4@Mn Fe2O4 particles. After being treated with NOBF4 to be converted water soluble and mixed with PVA and Fe3+ to polymerize pyrrole, the uniform sized Co Fe2O4@Mn Fe2O4/polypyrrole magnetic nanocomposites with an average hydrodynamic size of ~110 nm were synthesized. Their saturation magnetization were ~20 emu/g and the r2 value was about 200 m M-1s-1 which showed a significant MRI property. Besides, the material can combine two thermal therapy methods to kill cancer cells more effectively.In the third chapter, we synthesized uniform sized Fe2C5-DSPE-m PEG nanoparticles with an average size of ~10 nm. After coated with lipid, the nanoparticles showed water solubility and stability. The magnetic nanoparticles can act as T2 contrast agents and have high stability after laser irradiation and high photothermal conversion efficiency. After DOX loading, the low cytotoxicity Fe2C5-DSPE-m PEG NPs are highly effective for both in vitro and in vivo cancer cell ablation by chemo-photothermal co-therapy.