Abstract

Smart MR contrast agents exhibit modulation of their relaxivity by specific physiological or biochemical trigger-events, while targeted MR contrast agents are envisioned to deliver the large gadolinium chelates into the target tissue. In an effort to develop novel smart and targeted MR contrast agents, the series of the DO3A based multifunctional chelating agents with the variable length of the side chain has been synthesized. They serve as valuable multipurpose precursors for contrast agents based on gadolinium chelates in the design of relaxometric MR probes. The presence of the amino group in the side chain of the macrocycle allows for conversion into various functional groups (aminophosponates, aminocarboxylates, etc.) or for conjugation with different biomolecules, dyes, and polymers. Choice of the functional groups depends on the..