载Fe_3O_4液态氟碳纳米粒增强磁共振成像的实验研究

Experiment study of Fe_3O_4-loaded lipid perfluorooctylbromide nanoparticles as a contrast agent for enhanced magnetic resonance imaging

目的制备载Fe3O4液态氟碳(Fe3O4-PFOB)纳米粒,并探讨其增强磁共振成像效果。方法采用薄膜-超声法制备Fe3O4-PFOB纳米粒,并检测其理化性质。将24只健康SD大鼠随机分为3组:Fe3O4-PFOB纳米粒组(静脉注射Fe3O4-PFOB纳米粒)、PFOB纳米粒组(静脉注射PFOB纳米粒)及生理盐水组(静脉注射生理盐水)。对各组大鼠于处理后24 h行肝脏MR扫描。扫描完成后取出大鼠肝脏组织,进行HE及普鲁士蓝染色观察。结果所得样品为膜壳装载Fe3O4、中心包裹液态氟碳的纳米粒,呈球形,粒径(272.9±19.5)nm。注射Fe3O4-PFOB纳米粒24 h后,大鼠肝实质信号显著降低,肝脏-肌肉信号比明显减少,与其余两组比较差异均有统计学意义。普鲁士蓝染色可见Fe3O4-PFOB纳米粒组大鼠肝实质内有较多蓝色颗粒分布,其余两组染色阴性。HE染色各组大鼠肝脏均未见明显的形态学改变。结论 Fe3O4-PFOB纳米粒能有效增强磁共振成像效果,可以用作MRI阴性对比剂。

Objective To prepare Fe3O4-loaded lipid perfluorooctylbromide（Fe3O4-PFOB） nanoparticles,and to explore its potential application as a MRI contrast agent.Methods Fe3O4-PFOB nanoparticles were prepared using a film-ultrasonic method.Then the physical and chemical properties were observed.Twenty-four SD rats were randomized into 3 groups（each n=8）： group 1（injection with Fe3O4-PFOB nanoparticles）,group 2（injection with PFOB nanoparticles） and group 3（injection with normal saline）.MR scanning were performed 24 h after the administration.Immediately after MR scanning,sections of the rats＇ livers were stained with HE and Prussian blue.Results Fe3O4-PFOB nanoparticles consisted of a shell of lecithin loaded with Fe3O4 particles and a liquid core of PFOB.Fe3O4-PFOB nanoparticles were spherical in shape and homogeneous in size（272.9±19.5）nm.The signal intensity of liver parenchyma reduced markedly 24 h after injection of Fe3O4-PFOB nanoparticles.The signal ratio of liver to muscle decreased significantly compared with the other groups.Prussian blue stain showed accumulation of blue particles within liver tissues in group 1,while no particles were found in the other groups.HE stain showed no change of liver formation in all groups.Conclusion The newly formulated Fe3O4-PFOB nanoparticles can effectively enhance MR imaging in vivo,and has a potential to be a versatile image probe for MRI.