Two-Compartment Pharmacokinetic Modeling of Targeted Molecular MRI Contrast Agents

Marlies Oostendorp^1,2, Kim Douma^1,2, Tilman M. Hackeng^1,2, Marc A.M.J. van Zandvoort^1,2, Mark J. Post^1,2, Walter H. Backes^1,2

The dynamic homing behavior and pharmacokinetics of targeted molecular MRI contrast agents are largely unknown. Moreover, it is unknown whether these typically large particles can penetrate the entire tissue or not. Here, a simple two-compartment model is presented that provides unique information on the pharmacokinetic behavior of cNGR-labeled paramagnetic quantum dots (cNGR-pQDs) targeted to the angiogenic tumor vasculature in mice. Compared with a non-targeted control particle, significant differences were found in both association and dissociation related parameters. In addition, significant differences were found throughout the tumor, indicating that the targeted contrast agent can indeed penetrate the entire tumor tissue.