生物相容性Fe_3O_4@SiO_2纳米粒子的合成及性能

背景：Fe3O4纳米粒子具有良好的磁学特性,SiO2具有良好的生物相容性,Fe3O4@SiO2复合纳米粒子有望成为靶向治疗的载体。目的：采用反相微乳液法合成生物相容性的Fe3O4@SiO2纳米粒子。方法：首先,以FeCl3？6H2O、FeCl2？4H2O、油酸、氨水等为原料,采用一壶化学共沉淀法合成油酸修饰的疏水性Fe3O4纳米粒子。随后,将油酸包裹的Fe3O4纳米粒子分散于环己烷中,然后将Triton-X100、正己醇及水在搅拌条件下加入到上述溶液,形成稳定的反相微乳液;在反相微乳液中,以氨水为催化剂,使正硅酸四乙酯水解、缩合,从而获得Fe3O4@SiO2复合纳米粒子。结果与结论：①透射电镜、X射线衍射显示：采用一壶化学沉淀法合成的Fe3O4具有尖晶石结构,平均粒径约为3.5nm;微乳液法能将SiO2成功包覆于Fe3O4表面,形成平均粒径为40nm的均一Fe3O4@SiO2复合纳米粒子。②磁性能分析显示：Fe3O4纳米粒子包裹后饱和磁化强度下降,但包裹前后矫顽力趋于零,均显示超顺磁性。③MTT结果显示纳米粒子与人脐静脉细胞融合细胞（EA.hy926）共培养24h时Fe3O4@SiO2组吸光度高于对照组（P〈0.05）;细胞培养48,72h,两组比较差异无显著性意义（P〉0.05）。结果表明经反相微乳液法合成的Fe3O4@SiO2纳米粒子是一种优良的生物材料,其具有稳定、易分散及超顺磁性等特性。

Preparation and characterization of biocompatible Fe_3O_4@SiO_2 nanoparticals

BACKGROUND：Fe3O4 nanoparticles have good magnetic properties,SiO2 has good biocompatibility,and Fe3O4@SiO2 composite nanoparticles are expected to become the carrier of targeted therapy.OBJECTIVE：To prepare the biocompatible Fe3O4@SiO2 nanoparticles via a reverse microemulsion.METHODS：Firstly,hydrophobicity Fe3O4 nanoparticle modified oleic acid were prepared via a one-pot chemical coprecipitation with FeCl3？6H2O,FeCl2？4H2O,oleic acid and NH3？H2O.Subsequently,Fe3O4 nanoparticles stabilized with oleic acid were dispersed in cyclohexane,and then Triton-X100,hexylalcohol and H2O were added into the above solution and stirred to form stable reverse microemulsion;In the reverse microemulsion,using ammonia solution as a catalyst,tetraethyl orthosilicate（TEOS） was hydrolyzed and condensed to form Fe3O4@SiO2 compound nanoparticles.RESULTS AND CONCLUSION：①The structure of Fe3O4 nanopartides prepared by a one-pot chemical coprecipitation was spinel,having a mean diameter of 3.5 nm;Through microemulsion methods,SiO2 were coated successfully on the surface of Fe3O4 nanopartides,and the uniform Fe3O4@SiO2 nanoparticles with a mean diameter of 40 nm were obtained.②Although the saturation magnetization decreased after Fe3O4 nanopartides being coated,the coercivity of magnetic nanoparticles was near zero before and after encapsulation,revealing Fe3O4 and Fe3O4@SiO2 nanoparticles are of superparamagnetic properties.③After EA.hy926 cells were cultured accompanied with Fe3O4@SiO2 nanoparticals,the absorbance value of Fe3O4@SiO2 nanoparticles was markedly higher than that of control group（P 0.05）;At 48 and 72 hours of cell culture,no significant difference was found in the absorbance value between the two group（P 0.05）.The results showed Fe3O4@SiO2 compound nanoparticle using a reverse microemulsion is a kind of excellent biomaterial because of its stable,dispersive and superparamagnetic properties.