Preparation Of Magnetic Nanocomposites And Their Application In Tumor Diagnosis And Treatment

Nanoscience and nanotechnology have gained significant momentum in recent years to interplay with biology and medical science,leading to the emergence of nanomedicine.Nanomedicine can be used in the diagnosis and treatment of cancer due to the special physical effects of nanoparticles.Among different types of nanomaterials,magnetic nanoparticles?MNPs?possess unique magnetic properties and the ability to function at the cellular and molecular level of biological interactions making them an attractive platform as contrast agents for magnetic resonance imaging?MRI?,as carriers for drug delivery or as heat mediators in hyperthermia treatments.The most widely studied and applied MNP are superparamagnetic iron oxide nanoparticles due to their super-paramagnetic properties.Superparamagnetic iron oxide nanoparticles exhibit high saturation magnetization at room temperature in an external magnetic field but it disappears when the magnetic field is removed by thermal agitation.That is to say,magnetization of the superparamagnetic iron oxide nanoparticles can be altered with sufficient thermal energy.The ability of magnetic heating and the ability of T₂ magnetic resonance imaging are directly proportional to the saturation magnetization.Although ferromagnetic iron oxides are highly magnetic,they are rarely used in studies because of their easily clustered defects.The weakly ferromagnetic iron oxides are not easily gathered and strongly magnetic,so it is worth studyingIn this work,we firstly synthesize the ferromagnetic iron oxides nanomaterials?FION?by the thermal decomposition method,and finally a novel thermo responsive magnetic nanoparticlespoly?Nisopropylacrylamide-co-acrylamide?@SiO₂@Fe₃O₄hasbeen successfully prepared.The magnetic nanoparticles with thermo-sensitivity were characterized by X-ray diffraction?XRD?,transmission electron microscopy?TEM?,dynamic light scattering?DLS?,Fourier transform infraredspectrometer?FTIR?.Temperature rise curve of pNIPAAm-co-pAAm@SiO₂@FION show magnetic nanoparticles have good thermal performance.Magnetic resonance imaging?MRI?results demonstrate that magnetic nanoparticles prepared by our novel synthetic route could potentially be used as MRI contrast agents.Besides,the drug loading capacities and the releasing behavior of the magnetic nanoparticles were investigated with 5-Fluorouracil as an anticancer drug model.The resulting magnetic nanoparticles load and release5-Fluorouracil under an appropriate condition.In vitro release experiments revealed that release was faster at 42? than at 25?.Due to the strong magnetic properties of ferromagnetic iron oxides,the magnetic nanocomposites can enter the cell faster.Cell activity experiments show that the material has potential for the treatment of cancer.