Chang-Tong Yang1, Cai-Xian Yong1,
Chew-Yuan Tuang2, Young-Tae Chang2, Kai-Hsiang Chuang1
1Laboratory of Molecular Imaging,
Singapore Bioimaging Consortium, Agency for Science,Technology and Research,
Singapore, Singapore; 2Laboratory of Bioimaging Probe Development,
Singapore Bioimaging Consortium, Agency for Science,Technology and Research,
Singapore, Singapore
We
developed a new Gd(III) chelate by conjugating GdDO3A with
2-(diphenylphosphoryl)ethyldiphenylphosphonium cation -- Gd(DO3A-xy-TPEP)+ to
form a cationic MRI contrast agent. This contrast agent has been synthesized
and characterized in vitro and in vivo. In vitro cell viability showed
insignificant cytotoxicity at low [Gd] concentrations up to 0.2 mM. The in
vitro T1 relaxivity measured at 7.0 T is about 50% higher than that of
clinically used Gd-DTPA and Gd-DOTA. In vivo imaging study in mice
demonstrated longer tissue retention especially in the liver. It indicated
that Gd(DO3A-xy-TPEP)+ could potentially be used to detect tumor which
generally has larger negative mitochondrial transmembrane potential.
Keywords