Preparation And Characterization Of Magnetic Drug Nanospheres

Magnetic drug nanospheres consist of magnetic nanoparticles, drug and framework materials, it could be selectively localized to the tragetsite of turmor by external magnetic field and thus it achieve high drug concentration to the cell and reduce undesirable toxic effects. Therefore, magnetic drug nanospheres have received great and wide attention in the field of cancer treatment. Currently, although magnetic drug nanospheres show special advantage on the target treatment of the tumor, the whole development level of the domestic and abroad still lies in the foudamental stage, it also exists much shortage. Therefore, we put our research emphasis on preparation of the superior particle diameter, high magnetic susceptibility, particles carrying a high the medicine rate.The main content in this parer as follows:1. The preparation and characterization of Magnetic nanoparticlesMagnetic nanoparticles were prepared by chemical co-precipitation process.Reactant molar ratio, the concentration of molysite, pH value, reaction temperature, curing temperature and the concentration of precipitator were found to dramatically influence the properties. The property were obtained and measured by XRD,VSM,SEM,TEM and IR.The optimal manufacturing condition were determined as follows: the ratio of molar was 1:1.7,the concentration of molysite was 0.7 mol/L, pH value was 10, reaction temperature was 30℃, curing temperature was 60-70℃and the concentration of concentrate was 2mol/L. The X-ray diffraction indicates that the Fe₃O₄ particles obtained from optimal manufacturing condition are pure particles and the average diameter is 17nm. The saturated magnetization of the particles is 68.67emu/g.2. The preparation and characterization of Fe₃O₄/chitosan composite nanospheres Fe₃O₄/chitosan composite nanospheres were based on ionic gelation process,we carried on the further quest and research.The influences of preparation conditions was studied, including the concentration of chitosan and sodium tripolyphosphate, the volume of chitosan and sodium tripolyphosphate. In order to gain the best parameters for preparing nanospheres, the influences were evaluated by orthogonal-designing method. The optimal manufacturing condition were determined as follows: the concentration of chitosan was 2 mg/ml, the concentration of sodium tripolyphosphate was 2mg/ml, the volume of chitosan was 20ml and the volume of sodium tripolyphosphate was 3 ml.It was indicated that the average size of composite nanospheres is about 50nm and the saturated magnetization is 53.8 emu/g.3. The preparation and characterization of magnetic drug nanospheresThis subject was to synthesize magnetic drug nanospheres, we coupled drug 5-Fluorouracil(5-Fu) to Fe₃O₄ based on the framework of chitosan. The encapsulation efficiency of 5-Fu and drug loading was influnced by the chitosan concentrate and the 5-Fu concentrate. Drug releaseing property of magnetic drug nanospheres was studied, the release behavior of 5-Fu exhibited a triphasic pattern characterized by a fast release stage, spread stage and ballence stage. The percentage of 92% of the total 5-Fu loaded in magnetic drug nanospheres could be released. The 5-Fu release from nanospheres could be described by the following equation: y=30.7-25.47*exp(-0.01256x).