PEI修饰磁性Fe3O4纳米粒的制备和表征

 为了制备性能良好的聚乙烯亚胺（PEI）修饰的磁性Fe3O4纳米粒，以及为进一步开展体内外生物学效应分析奠定基础，采用化学共沉淀法制备PEI修饰的磁性Fe3O4纳米粒。PEI-Fe3O4纳米粒的制备包括磁性Fe3O4纳米粒的制备和PEI修饰磁性Fe3O4纳米粒两部分，采用4因素2水平的正交实验对各因素进行优化，得到较佳的制备工艺。反应过程中用过量氨水保持pH值为9.3~9.7，Fe2+与Fe3+的物质的量比为1:1.75，PEI水溶液的质量百分数为20%，反应温度始终保持为85℃，机械搅拌速率为1400r/min。采用傅里叶变换红外光谱仪（FTIR）、透射电子显微镜（TEM）、X射线衍射分析仪（XRD）、振动样品磁强计（VSM）、热重分析仪（TGA）对磁性纳米粒的物化特征进行表征。结果表明，制得的磁性PEI-Fe3O4纳米粒为接近圆形或椭圆形粒子，具尖晶石结构，粒径约9.4nm，磁含量为82.3%，饱和磁化强度为61.962emu/g，矫顽力几乎为0，具超顺磁性，稳定性和分散性良好。

Preparation and Characterization of Polyethyleneimine Modified Fe3O4 Magnetic Nanoparticles

The orthogonality test was used to obtain the optimal technology for preparing magnetic nanoparticles coated with covalently-bound biofunctional polyethyleneimine (PEI). We propose PEI-Fe3O4 magnetic nanoparticles as a mediator for hyperthermia in vitro and in vivo. The processing of polyethyleneimine modified Fe3O4 magnetic nanoparticles includes the preparation of magnetic Fe3O4 nanoparticles and then integrating the Polyethyleneimine modified magnetic nanoparticles and Fe3O4. Examination and characterization of the polyethyleneimine modified Fe3O4 magnetic nanoparticles were performed using simple methods. Simple analyses of the factors affecting the preparation of polyethyleneimine modified Fe3O4 magnetic nanoparticles were made, and the optimal technology was obtained after the optimization of these factors by means of a L8(27) orthogonality test. The optimal technological conditions obtained were: use of ammonium chloride to keep the pH in the range of 9.3~9.7; the ferric ions must be kept in the ratio Fe2+/Fe3+=1:1.75; a polyethyleneimine solution with mass-fractional of 20% should be used; a mechanical stirring at of 1400r/min should be maintained; and the reaction temperature should be held at 85℃. The resulting polyethyleneimine modified Fe3O4 magnetic nanoparticles were characterized using Fourier transform infrared spectroscopy, transmission electron microscope, X-ray diffraction, vibrating sample Magnetometry, and Thermogravimetric Analysis. The results show that the particles have a spinel structure, are superparamagnetic, and have good performance Their diameter is about 9.4nm, their magnetic concentration is 82%, and their magnetization is 61.962emu/g. Further investigation is needed to confirm the nanoparticles effectiveness as a mediator for hyperthermia in vitro and in vivo.