Objective: We try to establish designs for the macromolecular agents possessing high Gd3+-chelating stability, because free Gd3+ ion released from Gd chelates is known as a risk factor to cause toxic side effects and a safety concern.
Materials and methods: We prepared three types of Gd-based macromolecular MRI contrast agents from a synthetic polymer (poly(glutamic acid) homopolymer or poly(ethylene glycol)-b-poly(lysine) block copolymer) and a chelating moiety (DO3A or DOTA) having two strategic designs for high chelate stability. Then, we examine the in vitro Gd3+-chelate stability of these macromolecular MRI contrast agents.
Results: The prepared macromolecular agents exhibited the same or higher Gd3+-chelate stability as/than did Gd-DOTA that possesses the highest Gd3+-chelate stability among the approved small-MW Gd-chelate MRI contrast agent.
Discussion: Our macromolecular design was considered to work well for high Gd3+-chelate stability.
Keywords: Chelating stability; Contrast agent; Gd-chelate; Macromolecular contrast agent; Polymeric micelle.