稳定的水溶性Fe_3O_4纳米粒子的制备及其表征

Synthesis and characterization of stable water-soluble Fe_3O_4 nanoparticles

目的:制备稳定的水溶性Fe3O4纳米粒子(PMAT-Fe3O4)磁共振成像(MRI)造影剂,并对合成的粒子进行表征。方法:利用高分子聚-1-十四碳烯-马来酸酐(PMAT)修饰油溶性Fe3O4纳米粒子表面,使粒子表面富含亲水性羧基基团,使粒子能够稳定存在于水相中,并用透射电镜(TEM)、动态光散射(DLS)、振动样品磁强计(VSM)、傅立叶红外吸收光谱(FT-IR)和MRI等方法进行表征。结果:(1)TEM分析显示,PMAT-Fe3O4粒子直径约为10 nm,DLS测定其水动力学平均直径约为80 nm;(2)PMAT-Fe3O4粒子能稳定分散于去离子水、PBS、Tris、MES等缓冲液中,不发生团聚;(3)VSM、MRI等分析手段显示,PMAT-Fe3O4的饱和磁化强度Ms≈14.0 emu.g-1,弛豫率r2=367.79 mM-1s-1。结论:PMAT-Fe3O4具有良好的水溶性、磁学性能和较高的r2值,有望发展成为一种性能优异的MRI造影剂。

Objective： To synthesize stable and water-soluble PMAT-Fe3O4 nanoparticles（NPs） as MRI contrast agent and characterize it.Methods： Poly maleic anhydride alt-1-tetradecene（PMAT） was utilized to modify the surface of oil-soluble NPs,and the obtained PMAT-Fe3O4 NPs were characterized by TEM,DLS,FT-IR,VSM and MRI.Results：（1） TEM and DLS studies showed that the PMAT-Fe3O4 NPs have a magnetic core size of about 10 nm and a hydrodynamic diameter of about 80 nm.（2） PMAT-Fe3O4 could keep stable in water and familiar buffers,such as MES,PBS and Tris without aggregation.（3） VSM measurements showed that the saturation magnetization（Ms） was about 14.0 emu·g-1,the relaxivity value（r2） of PMAT-Fe3O4 was 367.79 mM-1s-1.Conclusion： The obtained PMAT-Fe3O4 NPs possess outstanding water-solubility,good magnetic properties,and high r2 value,which are therefore expected to become an excellent MRI contrast agent.