Study On Magnetic Nanoparticles For Cancer Local Therapy

The goal of this study was the preparation of Magnetic Nanoparticles (MNPs) asdrug delivery systems for cancer treatment. Magnetic Nanoparticles were preparedby a method of co-precipitation with polymer matrix. The raw materials are ferricchloride and ferrous chloride, and magnetic nanoparticles were provided by addingsodium hydroxide to dextran aqueous solution. After precipitation, the magneticprecipitate was purified via membrane dialysis and high speed centrifugationrespectively. Precipitation was mainly effected with the concentration of base and matrix,Fe2+/Fe3+ mol rate, reaction temperature and stirring rate. All the factors wereinvestigated and the technique of preparing the smallest (<100nm) magneticnanoparticles was optimized in this study. Dextran magnetic nanoparticlces andO-Carboxymethylated Chitosan (O-CMC) magnetic nanoparticles with the smallestaverage diameter (<100nm) and super-paramagnetic property were obtained andmeasured by TEM (JEOL 100CX-II), VSM (Vibrating Samples Magnetometer,LDJ9600-1), AFM (Nanoscope IIIa, DI, USA), IR spectrum (Bio-Rad FTS 135) andXPS (X-ray Photoelectron Spectroscopy). Meanwhile, the local accumulation of products was observed and characterizedthrough a model to simulate Blood Circulation in bodily capillary vessels with thepresence of an external magnet field. In the study, the influence of magnetic fieldintensity and fluid rate were investigated, and the conglomeration qualification wasobtained via analyzing the experiment data and figuring with mathematical model. In order to investigate the carry capacity of products, MTX-Dextran MNP andMTX-O-CMC MNP were prepared with the method of Oxidation-reduction andEDCI respectively. The two delivery systems were characterized by TEM, AFM,VSM, and UV. It is proved that the two MTX-MNPs preserved the property ofsuper-paramagnetic, and also, the diameter, drug content of the two MTX-MNPs wasexcellent. Then U937 cell line was selected to investigate the anti-tumor effects ofthe two MTX-MNPs after being compared with other three cell lines, includingHL-60, CEM, K562. The results demonstrated that the drug-loaded MNPs had thehigh anti-tumor effects (>80%) and showed a sustain-release behavior in several days,especially sustain-release behavior of the MTX-O-CMC MNP is more obvious, whichprovided a foundation to the animal experiment and clinical experiment.