Multifunctional gadolinium-based ligand DO3A-EA as novel precursor for conjugation with bioorganic molecules to develop smart contrast agents for MR imaging

A. Mishra, J. Pfeuffer, R. Mishra, N. K. Logothetis, A. K. Mishra Department Physiology of Cognitive Processes, Max Planck Institute for biological Cybernetics, Tuebingen, D, Germany, High Field MR Center, Max Planck Institute for biological Cybernetics, Tuebingen, D, Germany, Radiopharmaceutical Div., INMAS, Delhi, IN, India Introduction To image directly neuronal activity by means of magnetic resonance, the physiological changes occurring during neural activation must be converted into detectable MR image contrast. Smart MR contrast agents (CA) exhibit modulation of their relaxivity by specific physiological or biochemical trigger-events such as changes in pH, calcium ion, neurotransmitter concentration, enzymatic activity, or the binding of an intracellular messenger [1]. In an effort to develop novel smart MR contrast agents, the multifunctional chelating agent DO3A-EA has been designed and synthesized. It serves as a valuable multipurpose precursor for smart contrast agents based on Gadolinium chelates in the design of relaxometric MR probes. Several applications are reported after conjugation with diverse bioorganic molecules. This demonstrates the importance and potential of the precursor not only in the design of 'smart' CA, but also for multifunctional 'targeted' CA.