Mn^(2+)-NaY型分子筛作为口服胃肠道MRI造影剂的研究

Zeolites Mn^(2+)-NaY as Oral Gastrointestinal Tract Contrast Agents in Magnetic Resonance Imaging

用离子交换法制备了Mn2+交换的NaY分子筛MnNaY,用红外光谱(IR)和X射线粉末衍射(XRD)等方法进行了表征.研究了Mn2+含量为3.2%的样品在酸性水溶液中的稳定性和离子交换选择性.弛豫时间测量和体内磁共振成像实验表明其弛豫效率变化范围为4.9～9.7mmol·L·s-1,高于目前临床所用造影剂Gd-DTPA,对胃部MRI信号具有良好的增强效果.它是比较好的潜在口服胃肠道造影剂.

Mn^2＋ -loaded zeolites were prepared by ion-exchange of NaY with MnCl2 and characterized by IR and XRD. The stability of MnNaY （3.2% Mn） at low pH and in the presence of metal ions at a concentration relevant to the gastrointestinal tract has been evaluated. The T1-relaxivities of MnNaY decreased as the Mn^2＋ loading increased from 3.2% to 5.2%, with values ranging between 4.9 and 9.7 mmol·L·s^-1at 400 MHz and 23℃. Tl-weighted magnetic resonance imaging （MRI） of rats＇ abdomen showed a remarkable enhancement after oral administration of MnNaY （3.2% Mn）. The results indicate that the MnNaY may be a potential gastrointestinal tract contrast agent for MRI.