Abstract #1894

In Vitro and in Vivo Characterization of (Albumin-Binding) Dendritic MRI Contrast Agents for Dynamic Contrast-Enhanced MRI

Igor Jacobs¹, Siem Wouters¹, Henk Keizer², Henk Janssen², Eliana Gianolio³, Silvio Aime⁴, Gustav J. Strijkers¹, Klaas Nicolay¹

¹Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands; ²SyMO-Chem BV, Eindhoven, Netherlands; ³Dipartimento di Chimica & Centro di Imaging Molecolare, Universit degli Studi di Torino, Torino, Italy; ⁴Dipartimento di Chimica & Centro di Imaging Molecolare, Universit degli Studi di Torino, Torino, N\A, Italy

DCE-MRI is widely used for evaluation of tumor treatment. Macromolecular contrast agents may be preferred for determination of specific pharmacokinetic parameters and treatment-induced vascular changes. In this study (albumin-binding) dendritic contrast agents of various molecular weights were extensively characterized. Albumin-binding (confirmed in vitro) led to increased circulation half-lives, while a size-dependent range of circulation half-lives was observed for the non-albumin-binding dendrimers. Tumor/muscle uptake ratios of the dendrimers were higher than of Gd-DOTA. These findings imply that these agents likely possess a range of tumor wash-in and wash-out rates, making them suitable for investigation of the size-dependency of pharmacokinetic parameters.