Radioimmune & Inorganic Chemistry Section, Radiation Oncology Branch, National Cancer Institute, Bethesda, MD 20892, United States.
J Inorg Biochem. 2011 May;105(5):722-7. doi: 10.1016/j.jinorgbio.2011.01.017. Epub 2011 Apr 2.
We report in vivo and in vitro MRI properties of six gadolinium-dendrimer and gadolinium-albumin conjugates of derivatized acyclic diethylenetriamine-N,N',N',N″, N″-pentaacetic acid (1B4M) and macrocyclic 1,4,7,10-tetraazacyclododecane-N,N',N″,N‴-tetraacetic acid (C-DOTA). The three albumin-based agents have comparable protein to chelate ratios (1:16-18) as well as molar relaxivity (8.8-10.4 mM(-1) s(-1)). The three dendrimer based agents have blood clearance half-lives ranging from 17 to 66 min while that of the three albumin-based agents are comparable to one another (40-47 min). The dynamic image obtained from use of the albumin conjugate based on the macrocycle (C-DOTA) showed a higher contrast compared to the remaining two albumin based agents. Our conclusion from all of the results is that the macrocyclic-based (DOTA) agents are more suitable than the acyclic-based (1B4M) agent for in vivo use based on their MRI properties combined with the kinetic inertness property associated with the more stable Gd(III) DOTA complex.
我们报告了六种钆树状大分子和钆白蛋白轭合物的体内和体外 MRI 性质，这些轭合物衍生自非循环二亚乙基三胺-N，N'，N'，N″，N″-五乙酸（1B4M）和大环 1,4,7,10-四氮杂环十二烷-N，N'，N″，N‴-四乙酸（C-DOTA）。这三种基于白蛋白的试剂具有相当的蛋白与螯合物比（1:16-18）以及摩尔弛豫率（8.8-10.4 mM-1s-1）。三种基于树状大分子的试剂的血液清除半衰期范围从 17 到 66 分钟，而三种基于白蛋白的试剂的半衰期彼此相当（40-47 分钟）。使用基于大环（DOTA）的白蛋白缀合物获得的动态图像显示出比其余两种基于白蛋白的试剂更高的对比度。根据这些 MRI 性质以及与更稳定的 Gd（III）DOTA 配合物相关的动力学惰性性质，我们得出的结论是，大环基（DOTA）试剂比非环基（1B4M）试剂更适合体内使用。
