Study On Targeted Drug-Loaded Magnetic Biodegradable Polymer Microspheres

In this thesis, a significant research on targeted drug-loaded magnetic polymer microspheres has been carried out as to the deficiency of normal drug administration. Biodegradable polymer and Fe₃O₄ nanoparticles were chose as drug carriers, and drug-loaded magnetic polymer microspheres can be delivered to the area of interest by an external magnetic field. Superparamagnetic Fe3O₄ nanoparticles were chose as magnetic core, which was characteristic of better biocompatibility and better magnetic properties. As biodegradable and biocompatible polymer, PLA and PLGA were chose as shell materials, which can protect drug from degradation, improving therapy efficacy, reducing drug toxicity. Based on these advantages, the drug-loaded magnetic polymer microspheres must have a potential in the treatment of cancer in the future. Firstly, Fe₃O₄ nanoparticles were prepared by the modified controlled chemical co-precipitation method, which can be well dispersed in water by the dispersion of surfactant (sodium oleate and poly-ethylene glycol). Then the size and size distribution of Fe3O₄ nanoparticles were determined by particle size analyzer, also the Fe3O₄ nanoparticles were characterized by X-ray powder diffraction (XRD) analysis, transmission electron microscopy (TEM), electron diffraction (ED) photography, Fourier transform infrared spectrometer (FT-IR), and vibrating-sample magnetometer (VSM). The 5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT) assay and histochemistry analysis were performed to evaluate the biocompatibility of magnetite nanoparticles. The results indicate that modified Fe3O₄ nanoparticles were characteristic of superparamagnetic behaviour, better biocompatibility and better magnetic properties, which can be promising as a...