摘要
树状大分子磁共振成像造影剂与小分子造影剂相比具有很高的质子弛豫增强及摩尔弛豫率,成像清晰度更好,有更长的血液循环时间等,因而具有十分乐观的应用前景。着重介绍了聚酰胺-胺(PAMAM)树状大分子钆螯合物造影剂的性质及应用研究情况。低代数(PAMAM-G2、G3、G4)树状大分子钆螯合物造影剂分子尺寸较小(小于6nm),相对而言可以迅速从肾排泄,能够作为肾功能性造影剂。高代数(PAMAM-G7、G8)树状大分子钆螯合物造影剂分子尺寸较大(大于12nm),可静脉注射用于血池造影剂,而PAMAM-G6大分子试剂可用于淋巴成像造影剂。对PAMAM树状大分子钆螯合物进行化学或生物学修饰,还可以使其具有肿瘤靶向性,并能作为钆中子捕获治疗(Gd-NCT)试剂。
Magnetic resonance imaging （MRI） contrast agents with dendrimer cores have larger proton relaxation enhancements and higher molar relaxivities, better imaging visualization and longer blood retention compared to those agents with small molecular weight. It suggests that this new class of contrast agent has the potential for diverse and extensive applications. The properties and application of polyamidoamine （PAMAM） dendrimer-based gadolinium complex contrast agents are reviewed briefly in the present paper. This entire series of dendrimer-based macromolecular MRI contrast agents have a spherical shape, and changes in molecular size alter the route of excretion. Smaller sized contrast agents（PAMAM-G2 ,G3, G4）are excreted through the kidney resulting in these agents being suitable as functional renal contrast agents. Larger sized contrast agents（PAMAM-G7, G8）are found better suited for use as blood pool contrast agents, and larger contrast agents（PAMAM-G6）are also useful for lymphatic imaging. Finally, macromolecular MRI contrast agents conjugated with either folate or with avidin are able to function as tumor-specific contrast agents and might also be employed as therapeutic drugs for gadolinium neutron capture therapy（Gd-NCT）.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2007年第5期69-72,共4页
Materials Reports
