论文部分内容阅读
以聚乙烯亚胺(PEI)为添加剂,在聚乙二醇(PEG)中高温热分解乙酰丙酮铁(Fe(acac)3),合成了超顺磁性氧化铁(SPIO)纳米粒子。采用X射线粉末衍射仪(XRD)、透射电子显微镜(TEM)、高分辨透射电镜(HRTEM)、超导量子干涉仪(SQUID)、热重分析仪(TGA)、傅里叶变换红外光谱仪(FT-IR)、纳米粒度与Zeta电位分析仪及小动物7T磁共振扫描仪对样品进行表征。结果表明,高温热分解法合成的粒子近似等轴晶形,当反应温度由180℃升高到260℃,粒径由(5.2±1.0)nm增加到(10±1.7)nm,并且结晶度增高,在室温下具有超顺磁性和高饱和磁化强度。PEG和PEI共同修饰于SPIO纳米粒子表面,使其在水溶液中能够长时间(90 d以上)稳定分散。在260℃下制备的纳米粒子,其磁共振弛豫T1和T2加权成像显示较好的对比效果,纳米粒子的纵向弛豫率r1为1.65 mmol·L-1·S-1,横向弛豫率r2为142.99 mmol·L-1·S-1,得到一个较高的r2/r1值,为86.6,生物体内成像实验表明所制备的纳米粒子可以作为一种优异的T2造影剂。
Superparamagnetic iron oxide (SPIO) nanoparticles were synthesized by the thermal decomposition of iron acetylacetonate (Fe (acac) 3) in polyethylene glycol (PEG) with polyethylenimine (PEI) as additive. The microstructure and mechanical properties were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), superconducting quantum interference (SQUID), thermal gravimetric analyzer (TGA) and Fourier transform infrared spectroscopy -IR), nano-particle size and Zeta potential analyzer and small animal 7T magnetic resonance scanner to characterize the sample. The results showed that when the reaction temperature increased from 180 ℃ to 260 ℃ and the particle size increased from (5.2 ± 1.0) nm to (10 ± 1.7) nm, the crystallinity of the synthesized particles was almost equiaxed. Superparamagnetism and high saturation magnetization at room temperature. PEG and PEI co-modified on the surface of SPIO nanoparticles, making them stable dispersion in aqueous solution for a long time (more than 90 days). The nanoparticle prepared at 260 ℃ showed better contrast effect on magnetic resonance relaxation T1 and T2 weighted imaging. The longitudinal relaxation rate r1 of the nanoparticles was 1.65 mmol·L-1 · S-1. The transverse relaxation rate r2 was 142.99 mmol·L-1 · S-1, a high r2 / r1 value of 86.6 was obtained. In vivo imaging experiments showed that the prepared nanoparticles can be used as an excellent T2 contrast agent.