The Preparation And Acute Toxicity Of Fe₃O₄ Nanoparticle

Nanosized material is also called ultramicro-particle material, composed of nanoparticles. It neither belongs to micro-system nor macro-system, but between them. It has many particular characterizations, such as volume effect, surface effect, quanta size effect, macroscopical quanta tunnel effect and so on because of its physical and chemical performances different from nubbly solid. Many researches have focused on its application in crossed subject such as bio-medical field. Combining Fe3O4 nanoparticles and exopolysacchrides from bifidobacterium enhances their using efficiency because nanoparticles are little toxical or not and not easily degraded by enzyme and possess good absorption. As a sub-question for discussion of national natural fund, this article was to prepare Fe3O4 nanoparticles and disscuss their influencing factors in order to establish theoretical foundation for anti-cancer and anti-tumour food and medicine. This article focused on the preparation of Fe3O4 nanoparticles by coprecipitation and their modification by sodium oleate. At the same time, the stabilization of non-modified and modified nanoparicle was also studied. The research results obtained were as follows: ⑴Continuous nitrogen and ceaseless agitating and titration method of alkali were all of importance for the well-proportioned size. The technical condition was: temperature was between 30 and 50 centigrade, final pH value was between 10 and 12, the ratio of Fe2+ and Fe3+ was 0.5, concentration of ferrite was 0.1mol/L, stirring velocity was 2000r/min. The size of obtained particles was 15nm. ⑵Dispersive results indicated that ultrasonic had limited separate ability even more than 2 minutes, but acid had better effect at pH value 3. Combining ultrasonic and acid treatment was feasible for better dispersion. ⑶Sodium oleate, as a kind of anion surface active reagent, its modification condition was: pH value was 5, the quantity accounted for 20% of total waterish nanoparticle powder, the temperature was 80 centigrade. ⑷The modified nanoparticles had better stabilities under lower concentration and lower centrifugal rate and pH value higher than 6.4. With the tremendous changes in physi-chemical characterization and property and intensity of bio-effect, the bio-security of nanoparticles have been paid attention to. Many factors such as surface area, amount, chemical characterization, surface-coated condition, freshness and variety and category of experimental animal all affect their toxic intensity. This article studied the acute toxicity of Fe3O4 nanoparticles of non-modified and modified on ICR-mouse by douching stomach. The research results obtained were as follows: ⑴Modified and non-modified nanoparticles were prepared colloid fluid by PVP-40 and their LD50 was higher than 3767mg/kg orally on ICR mouse. ⑵The mice all survived after two weeks. Nanoparticles was harmful to liver and lung to some extent, especially to liver. The modified nanoparticles was little toxical.