靶向磁性纳米粒子用于急性颞叶癫痫的MRI研究

Targeted magnetonanoparticles: localization of acute temporal lobe epilepsy on MRI

目的探讨具有功能性的靶向纳米探针用于磁共振分子成像定位急性颞叶癫痫模型致痫灶的价值和可行性。方法本实验将无放射性的α-甲基色氨酸(alpha-methyl-L-tryptophan,AMT)与磁性纳米粒子(Magnetonanoparticles,MNP)螯合成靶向纳米探针,将无表面修饰的MNP(plian MNP P-MNP)和生理盐水作为对照材料,于模型大鼠癫痫大发作后72 h分别经尾静脉注射,在注射前后行MR扫描并监测和比较致痫灶的信号T2值,之后断头取脑行普鲁士染色、尼氏染色及FJB染色等病理学检查。结果实验结果表明AMT-MNP和P-MNP能透过血脑屏障(the blood-brain barrier,BBB)且对脑组织无明显损伤。发现癫痫大鼠MRI中AMT-MNP使致痫灶T2信号呈负增强(P<0.05)。结论 AMT-MNP能透过血脑屏障并在磁共振成像中能靶向定位急性颞叶癫痫致痫灶。

Objective To investigate the functionalized magnetinanoparticles（ MNP） as imaging probe capable of crossing the blood-brain barrier（ BBB） and localizing epileptogenic cerebral regions of acute animal models of temporal lobe epilepsy on MRI. Methods In this study,a rodent model of temporal lobe epilepsy was prepared by injecting lithium chloride-pilocarpine. The targeted probe was synthesized by covalently attaching nonradioactive AMT to MNP. The plain MNP（ P-MNP） and the saline served as the control materials. AMT-MNP、P-MNP and the saline were injected into the models of temporal lobe epilepsy through the tail-vein during the acute stage 72 h after status epilepticus. MRIs were obtained before and after particles injection in all animals,and then the T2 value and signal of the epileptogenic tissue were measured and compared. To decollate and take the brain after MRIs to carry out histopathological examination. Results The study found that AMT-MNP and P-MNP could cross the BBB,and these particles did＇t injury the brain cells. AMTMNP promote significantly a T2 negative signal enhancement of epileptogenic cerebral regions in acute temporal lobe epilepsy on MRI. Conclusion AMT-MNP can cross the BBB and can accurately localize epileptogenic cerebral regions of acute temporal lobe epilepsy on MRI.