Contrast agent for blood pool imaging and targeted contrast delivery using rHA and Gd-DTPA
Wild J, Misselwitz B, Woodrow J, Johnson R
University of Sheffield
Significant quantities of Gd-DTPA were attached to the recombinant human albumin (rHA) molecule in the laboratory. The agent has a higher molar R1 and R2 in water (R1 = 7.2 s-1mM-1, R2 = 18.4 s-1 mM-1) than Gd-DTPA (R1 3.5 s-1 mM-1, R2 = 5.5 s-1 mM-1). In-vivo comparisons with Gd-DTPA and a polymeric Gd blood-pool agent, were made in rats and the clearance kinetics were examined. With free sites on the Gd loaded rHA molecule, there are possibilities for binding the agent to antibodies. This was demonstrated and thus the potential applications for targeted molecular imaging are highlighted.