【摘要】 天冬氨酸(ASP)自身热缩聚产物聚琥珀酰亚胺(PSI)通过与氨基化聚乙二醇单甲醚(α-胺基-ω-甲氧基-聚乙二醇)和十二胺(DDA)进行连续两步开环反应,制备了双亲性蜈蚣形聚合物聚琥珀酰亚胺接枝聚乙二醇与十二胺(PSI-g-PEG-DDA).随着改变疏水链段DDA的接枝比例,通过胶束粒径的变化确定了最佳的接枝比例.核磁共振波谱(1H-NMR)及凝胶渗透色谱(GPC)对聚合物的性质进行了表征.通过相转移法,聚合物对油溶性超顺磁性氧化铁纳米粒子进行包覆,制备了新型的水溶性超顺磁性氧化铁纳米粒子(PSI-g-PEGDDA@IONPs).动态光散射(DLS)和透射电镜(TEM)对新型的水溶性氧化铁纳米粒子的粒径与形貌进行了表征.体外T2核磁造影成像(MRI in vitro)确定了制备的氧化铁纳米粒子的R2质子驰豫率.肝癌小鼠模型的体内核磁造影成像(MRI in vivo)结果表明新型氧化铁纳米粒子对肿瘤部位有明显的T2核磁造影增强效应,并有很长的体内循环半衰期.以上实验结果表明,新型的水溶性纳米氧化铁粒子可以作为一种潜在的用于肿瘤检测的核磁造影剂.更多还原

【Abstract】 This research aimed to develop a novel polymeric micelle system to deliver iron oxide nanoparticles to tumor regions. To achieve the purpose above,the amphiphilic rentipede-like polymer poly( succinimide)-grafted-poly( ethylene glycol)-dodecylamine( PSI-g-PEG-DDA) was successfully synthesized. A study on structure and properties was conducted then through gel permeation chromatography( GPC) and nuclear magnetic resonance(1H-NMR). Through the phase transfer process,the amphiphilic polymer was used to encapsulate the superparamagnetic iron oxides( SPIOs) for preparing the stable water-soluble SPIOs. The product was found to form spherical micelles in aqueous media due to its amphiphilic nature with an average particle size of 50 nm measured by dynamic light scattering( DLS) and TEM imaging. Magnetization curve showed the water-soluble IONPs kept the superparamagnetic property of organic IONPs. An MTT assay showed no significant cytotoxicity of IONPs to HepG2 cells. Remarkably,MRI showed that IONPs displayed a clear concentration-dependent T2signal reduction effect,with an R2value of 187. 3( mmol / L)- 1s- 1. The result of mice magnetic response imaging( MRI) in vivo showed that this new type of SPIOs caused a great enhancement effect on T2magnetic resonance and long half-life in the circulation,which confirmed that it could be used as a potential contrast agent.更多还原