Contro Janine, Silva Danilo Antonio, Santisteban Oscar A N, Narayana Ponnada A, Nery José G
Departamento de Física, Instituto de Biociências, Letras e Ciências Exatas, UNESP-Universidade Estadual Paulista, São Paulo, Brazil.
Department of Diagnostics and Interventional Imaging, University of Texas-Health Science Center (UTHealth), Houston, Texas, USA.
J Biomed Mater Res B Appl Biomater. 2021 Aug;109(8):1105-1115. doi: 10.1002/jbm.b.34773. Epub 2020 Dec 6.
Gadolinium-based contrast agents (CAs) were synthesized using faujasite zeolite (NaX) and zeolite beta (BEA) and their performances in vitro and in vivo were compared to the widely used commercial CA, gadoteric acid (Gd-DOTA). Magnetic resonance imaging (MRI) relaxometry studies (considering longitudinal [T ] and transverse [T ] relaxation times) were performed using Gd-DOTA and the zeolitic materials loaded with Gd . The Gd-loaded NaX, which presented large pores and cavities (7.35 and 11.24 Å, respectively), exhibited relaxivity values of around 52 mM s , while BEA, which presented smaller pore and cavity diameters (5.95 and 6.68 Å, respectively) showed lower relaxivity values of ~4.8 mM s . The effect of the Gd-loaded NaX as MRI CA was tested in vivo in Sprague-Dawley rats, employing a 7 T scanner, with comparison to Gd-DOTA MRI angiography. The relaxivity measurements showed that the Gd-loaded NaX (50 mM s ) provided better image contrast than Gd-DOTA (5.1 mM s ). Clearance studies of the CAs using urine and blood showed that both Gd-loaded NaX and Gd-DOTA were eliminated from the body after 2 days, demonstrating the potential of Gd-loaded NaX for use as an MRI CA.
使用八面沸石（NaX）和β沸石（BEA）合成了基于钆的造影剂（CAs），并将其体外和体内性能与广泛使用的商用造影剂钆喷酸（Gd-DOTA）进行了比较。使用Gd-DOTA和负载钆的沸石材料进行了磁共振成像（MRI）弛豫测量研究（考虑纵向[T1]和横向[T2]弛豫时间）。负载钆的NaX具有大孔和大腔（分别为7.35和11.24 Å），其弛豫率值约为52 mM-1 s-1，而BEA的孔和腔直径较小（分别为5.95和6.68 Å），其弛豫率值较低，约为4.8 mM-1 s-1。在Sprague-Dawley大鼠体内使用7 T扫描仪测试了负载钆的NaX作为MRI造影剂的效果，并与Gd-DOTA磁共振血管造影进行了比较。弛豫率测量表明，负载钆的NaX（50 mM-1 s-1）比Gd-DOTA（5.1 mM-1 s-1）提供了更好的图像对比度。使用尿液和血液对造影剂进行的清除研究表明，负载钆的NaX和Gd-DOTA在2天后都从体内消除，证明了负载钆的NaX用作MRI造影剂的潜力。
