动脉粥样硬化靶向性磁共振造影剂的合成及理化特性鉴定

Synthesis and Physicochemical Characterization of Atherosclerotic Targeted Magnetic Resonance Contrast Agents

目的 将具有动脉粥样硬化病变靶向性的寡核苷酸适配子与超顺磁性氧化铁颗粒偶联，合成新型靶向性纳米磁共振造影剂。方法 采用壳聚糖共沉淀法包裹Fe3O4；傅里叶变换红外光图谱法判断包裹效果后，与寡核苷酸适配子偶联；聚丙烯酰胺凝胶电泳考察偶联情况；透射电镜法、X射线衍射分析法和MPMS XL-7磁学性质测量法评估其理化性质。结果 壳聚糖包裹形成的超磁性纳米Fe3O4颗粒能高效与寡核苷酸适配子偶联；形成的纳米颗粒粒径为10~20 nm；T2弛豫率为0.284 2×106 mol-1·s-1，质量饱和磁化强度为108 emu·g-1 Fe。结论 超顺磁性氧化铁与具有动脉粥样硬化病变靶向性的适配子偶联，形成的靶向性纳米体系符合磁共振铁造影剂的要求。

OBJECTIVE To synthesis chitosan-coated ultrasmall superpara-magnetic iron oxide （USPIO） nanoparticles and cross-link with atherosclerosis-target-aptamer. METHODS First, Fourier transform infrared spectroscopy （FT-IR） was used to identify the composition of nanoparticles. Aptamer was cross-linked with particles and polyacrylamide gel electrophoresis （PAGE） was used to identify the connection rate. Later on, the obtained nanoparticles were characterized by X-ray powder diffraction（XRD）, transmission electron microscopy（TEM）, vibrating sample magnetometer（VSM, MPMS XL-7 system）. RESULTS The USPIO were successfully synthesized and could be connect with aptamer in a high degree. The diameter of USPIO ranged from 10 to 20 nm. T2 relaxivity was 0.284 2×106 mol-1·s-1 and saturation magnetization was 108 emu·g-1 Fe. CONCLUSION The USPIO linked with aptamer as an atherosclerosis targeting chitosan nanocarrier is successful, the natures fit the requirements for iron contrast agent in MRI.