NRP-1分子探针的制备及其在脑胶质瘤磁共振成像中的应用

Preparation of NRP-1 molecular probe and its application in magnetic resonance imaging of glioma

【目的】制备神经纤毛蛋白-1靶向性分子探针,并研究其物理性质、磁成像性,探讨此分子探针应用于脑胶质瘤磁共振成像的可能性。【方法】利用碳二亚胺法合成USPIO-PEG-tLyP-1,采用动态光散射仪测量其粒径大小;建立U87裸鼠胶质瘤原位模型,经尾静脉注射分子探针后,利用原子吸收光谱仪测定不同脏器中的铁含量;MRI观察脑肿瘤、肝、肾组织的增强效果,比较各组织的R2值。【结果】合成的USPIO-PEG-tLyP-1粒径为44.77 nm。注射分子探针后,探针在心、肝、肺、肾组织中分布较少,而在脑肿瘤中分布最多,且注射后12 h脑肿瘤组织中含铁量达到最高。与注射前相比,注射后脑肿瘤、肝、肾组织T2WI信号明显降低,组织R2值比较差异有统计学意义(P<0.05)。注射后,脑肿瘤与肝、肾脏组织R2值比较,差异有统计学意义[脑肿瘤(16.99±0.87),肝脏(14.03±1.04),肾脏(12.80±0.79),F=16.95,P=0.003]。【结论】此分子探针物理性质稳定、靶向结合能力强、成像敏感度高,可用于脑胶质瘤的磁共振成像。

【Objective】To prepare the neurociliin-1 targeted molecular probe,and study its physical properties and magnetic imaging properties.To explore the application possibility of this molecular probe in magnetic resonance imaging of brain glioma.【Methods】USPIO-PEG-tLyP-1 was synthetized by carbon diimine method.The particle size was measured by dynamic light scatterer.An orthotopic transplantation model of U87 nude rat glioma was established,and the contents of iron in different organs were determined by atomic absorption spectrometer after the injection of molecular probe through tail vein.The enhancement effect of brain tumor,liver and kidney tissues was observed by MRI,and the R2 values of each tissue were compared.【Results】The particle size of USPIO-PEGtLyP-1 was 44.77 nm.After injecting molecular probes,the probes were less distributed in the heart,liver,lung and kidney tissues,but most distributed in brain tumors,and iron content was the highest in brain tumor tissue 12 h after injection.Compared with before injection,T2 WI signal in brain tumor,liver and kidney tissues was significantly decreased after injection,and the difference of tissue R2 value was statistically significant(P<0.05).After injection,brain tumor R2 value was compared with those of liver and kidney tissues,and the difference was statistically significant[brain tumor:(6.99±0.87),liver:(14.03±1.04),kidney:(12.80±0.79),F=16.95,P=0.003].【Conclusion】This molecular probe has stable physical properties,strong target-binding ability and high imaging sensitivity,and can be applied in magnetic resonance imaging for brain glioma.