First in vivo characterization of a low molecular weight Gd-metallostar a contrast agent with high relaxivity
Weidensteiner C, Kneuer R, Schmidt P, Livramento J, Allegrini P, Helm L, Tth , Merbach A
Novartis Institutes for BioMedical Research
In this study, the first in vivo characterization of a new contrast agent - a Gd-metallostar [Fe(Gd2L(H2O)4)3]-4 (3.7 kDa) - was performed in mice with dynamic contrast enhanced MRI (4.7 T). Its in vivo relaxivity and pharmacokinetics were compared to GdDOTA (0.56 kDa). The pharmacokinetics of the metallostar was similar to GdDOTA whereas its relaxivity was much higher. The results confimed that the in vivo relaxivity of the metallostar was very close to the value of 13.5 s-1mM-1 Gd as measured in saline (compared to 3.3 s-1mM-1 Gd for GdDOTA).