PEI、PEG修饰的SPIONs的制备及其在不同磁场强度下的磁共振对比

Synthesis of Superparamagnetic Nanoparticles Coted with Poly(ethylene glycol),Poly(ethylene imine) and Relaxation Behavior in Different Magnetic Field Strength

以乙酰丙酮铁(Fe(acac)_3)为铁源,聚乙二醇(PEG-1000)为溶剂、还原剂,聚乙烯亚胺(PEI)为修饰剂,采用高温热分解法制备PEI/PEG修饰的氧化铁纳米粒子(PEI/PEG-SPIONs)。采用X-射线衍射(XRD)、透射电镜(TEM)、热重分析仪(TGA)、傅里叶变换红外光谱仪(FT-IR)、纳米粒度与zeta电位分析仪、磁性能测试、磁共振成像(MRI)对样品进行表征。结果表明:PEI/PEG-SPIONs中含有Fe_3O_4晶相,形成了分散良好的球形粒子,没有团聚且有很高的结晶度,平均粒径为10.5±2.0 nm;PEI和PEG均修饰在了氧化铁纳米粒子的表面,使氧化铁纳米粒子具有良好的水分散性和生物相容性;具备优异的超顺磁性以及较高饱和磁化强度;MRI分析得知,电泳粒度为23.5 nm的PEI/PEG-SPIONs在3T和7T磁场强度下测得r2值分别为101.12 mM^(-1)S^(-1)和142.99 mM^(-1)S^(-1),均表现出较高的T2弛豫率。

The superparamagnetic iron oxide nanoparticles（SPIONs） were synthesized by thermal decomposition of Iron（Ⅲ） acetylacetonate（Fe（acac）3）, in which PEG（poly（ethylene glycol）） was used as solvent and reducing agent, and PEll, poly（ethylene imine）） was used as modifying agent. The samples were characterized with X-ray Diffraction（XRD）, Transmission Electron Microscopy（TEM）, Thermogravimetric Analysis（TGA）. Fourier Transform Infrared Spectroscopy（FT-IR）, panicles ＆ zeta potential Analyser,）, magnetism testing, Magnetic Resonance Imaging Analysis（MRI）. The results show that the Fe3O4 nanoparticles that we prepared had the crystalline phase of Fe3O4 and high crystallinity, were well-dispersed and no-union spherical particles with an average panicle size of 10.5±2.0 nm; The surfaces of Fe3O4 nanoparticles were modified by PEG（poly（ethylene glycol）） and PEl（poly（ethylene imine）） which provided good water dispersibility and good biocompatibility; The Fe3O4 nanoparticles showed excellent superparamagnetic behavior with high saturate maglaetization： MRI analysis showed that the r2 value of PEI/PEG-SPIONs, with an electrophoretic particle size of 23.5 nm, were 101.12 mM^-1S^-1 and 142.99 mM^-1S^-1 in 3T and 7T magnetic field strcngthrespectively, which were higher T2 relaxation rate.