Dendrimeric Gadolinium Chelate with Fast Water Exchange and High Relaxivity at High Magnetic Field Strength

Abstract
The synthesis and relaxivity properties of a new dendrimeric Gd chelate, Gd-TREN-bisHOPO-TAM-Asp-Asp2-12OH, are presented. The macromolecule demonstrates improved water solubility due to its 12 terminal hydroxyl groups and improved relaxivity due to its optimal water exchange rate and slower molecular tumbling. Unprecedented high relaxivity (r1p = 18 mM-1 s-1) is observed at high magnetic field (90 MHz), an important advance in the development of contrast agents for the next generation of MRI scanners.