The Preparation And Heat Effect Under Alternating Magnetic Field Of Fe₃O₄Magnetic Fluid

The Fe3O4magnetic nanaoparticles with special properties have been used in many field such as magnetic resonance imaging contract enhancement, tissue repair, hyperthermia, drug delivery and cell separation. Local hyperthermia treatment of cancers is to inject the magnetic thermoseeds into the tumour area of patient. The heating of cancer area containing the implanted thermoseeds to elevate temperatures in an external alternating-current magnetic field, induce apoptosis of tumour cells. The Fe3O4nanoparticles are perfect thermoseeds for local hyperthermia treatment of cancers with the super magnetic and inductive heating property.The Fe3O4magnetic nanaoparticles were prepared by chemical co-precipitation of Fe3+and Fe2+with NaOH solution. The results indicate that the magnetism and inductive heating property of Fe3O4particles can be effectively controlled by changing the condition of preparation. Nano-sized Fe3O4particles with strong magnetism but weak inductive heating property are synthesized under the condition of n(Fe2+):n(Fe3+) is 1.0:2.0,2.0;1.0,3.0:1.0,4.0:1.0, respectively. Nano-sized Fe3O4particles with strong magnetism and inductive heating property are synthesized under the optimum condition of n(Fe2+):n(Fe3+) is5.5:1.0.The size and structures of particles were analyzed by means of XRD, TEM and SEM. The results indicated that the particles are about5-20nm well-crystallized cubic particles with high purity and narrow particles size distribution.The specific saturation magnetization of Fe3O4nanoparticles prepared by co-precipitation is68.17emu·g-1under the optimum conditions of Fe2+:Fe3+value at5.5:1.0. The inductive heating property of Fe3O4nanoparticles physiological salt water aqueous suspensions move to high temperatures with the increasing of the preparation temperature and the particles’mass. The temperature that Fe3O4nanoparticles physiological salt water aqueous suspensions with concentration of2mg·ml-1reached is45℃in the alternating-current magnetic field, and they can be used as thermoseeds for local hyperthermia treatment of cancers.The Fe3O4fluid was prepared with strong inductive heating property particles and used different surfactant as stability matter. Experiment results indicated that surfactant have great effects on the stability of fluid. The temperature that Fe3O4fluid with concentration that higher than16.67mg·ml-1reached in the alternating-current magnetic field can be used as thermoseeds for local hyperthermia treatment of cancers.The Fe3O4/PEG complex particles were prepared by co-precipitation. The magnetism between Fe3O4/PEG and Fe3O4was compared and find that its have lower inductive heating property than Fe3O4patticles.