Preparation And Applications Of Nanoparticle Magnetic Chitosan Microspheres

The polymer magnetic microspheres are a new type of function material with wide applications in biochemical industry, cytology, and biomedical engineering. Magnetic chitosan microspheres which have been concerned deeply by people were due to their excellent biocompatibility, high stability and low toxicity for living body. Also owing to the abundant active groups on surface, chitosan magnetic microspheres can be chosen as immobilizing carrier. The groups on surface were activated, and then conjugated to biomolecules such as proteins, antibodies, peptid, DNA or RNA. As a new type of magnetic functional material, chitosan magnetic microspheres have a broad application perspective in the fields of enzyme fixation, immunity testing, cell separation and targeted drug, et. The major works described in this thesis include:(1)preparation and characterization of magnetite microspheres;(2)Research of targeting of nanoparticle magnetic chitosan microspheres (3) Research on the Extraction of beer Yeast RNA and the Conditions of Magnetic Immobilization Details are as follows.(1) In this paper, the Fe3O4nano-particles were prepared by co-precipitation method and modified by oleic acid. And then using the emulsification cross-linking technique to prepare composite chitosan magnetic microspheres, which contains dispersed Fe3O4nano-particles by adding proper amount of glutaraldehyde into chitosan solution. Finally, the preparation conditions are optimized. The SEM, IR and DLS results indicated that95.4%of the magnetic chitosan microspheres concentrated in the332.7nm, the diameter of the microspheres was about348.5nm and dispersion coefficient was0.283. There are abundant hydroxyls, amino and alcohol hydroxyl groups on surface and can be conjugated to biomolecules.(2)This paper is to find the targeting of nanoparticle magnetic chitosan microspheres through researching the process of magnetic microsphere and target experiment at animals.In this experiment, we divide the lab rat into three group:targeting group is the first one, none-targeting group is the second one and the last one is the blank control. Detecting the ironcontent in the liver of the lab rat through atomic absorption and infrared spectrum, with the result that the iron content in liver at the first group is obviously higher than the others. This result shows that the nano-magnetic chitosan microspheres have ideal targeting.(3) Extraction of beer yeast RNA by high concentration salt method. The magnetic chitosan microspheres as a carrier, through the glutaraldehyde cross-linking method, the magnetic immobilized RNA. By comparing the reaction system in the amount of inorganic phosphorus and total phosphorus content, the extraction of yeast RNA and immobilization conditions were optimized.From the experimental results, the extraction of yeast RNA temperature on extraction rate was the most significant factor; time of the extraction4h, temperature of the extraction was100℃, the concentration of sodium chloride concentration of10%and8%yeast under optimal conditions, yeast RNA’s extraction rate of6.13%. The magnetic microspheres conditions with glutaraldehyde as crosslinking agent immobilized RNA. The optimum conditions were achieved by experiments as follows:the conditions of time4h, the conditions of temperature40℃, the RNA solution30mL(2mg/mL).