On the Fate of MRI Gd-Complexes in Cells. Evidence for Extensive Degradation of Linear Complexes.

Eliana Gianolio¹, Enza Di Gregorio¹, Rachele Stefania¹, Silvio Aime¹

The use of highly stable complexes has been an important guide-line in the design of Gd-based contrast agents (Gd-CA). Many pre-clinical studies have been reported addressing the use of Gd-CA in cellular labeling experiments. In this presentation we report, for the first time, results concerning the stability of Gd-CA upon their cellular entrapment. Mass spectrometry was used for assessing the amount of intact Gd-complex inside cells upon time. Insights into the intracellular degradative mechanisms have been gained by analyzing the relaxometric NMRD profiles of cells labeled with the Gd-CA.