Polydisulfide-based Biodegradable Macromolecular Magnetic Resonance Imaging Contrast Agents

Authors

  • Zheng-Rong Lu,

    1. Department of Biomedical Engineering, Wickenden Building, Room 427, 10900 Euclid Avenue, Case Western Reserve University, Cleveland, OH 44106-7207, USA tel: +1 (0)216 368-0187 fax: +1 (0)216 368-4969
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  • Xueming Wu

    1. Department of Biomedical Engineering, Wickenden Building, Room 427, 10900 Euclid Avenue, Case Western Reserve University, Cleveland, OH 44106-7207, USA tel: +1 (0)216 368-0187 fax: +1 (0)216 368-4969
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Abstract

Macromolecular Gd(III) complexes are advantageous over small molecular Gd(III) complexes in contrast-enhanced magnetic resonance imaging (MRI) because of their prolonged blood circulation and preferential tumor accumulation. However, macromolecular contrast agents have not been approved for clinical applications because of the safety concerns related to their slow body excretion. Polydisulfide Gd(III) complexes have been designed and developed as biodegradable macromolecular MRI contrast agents to alleviate these concerns by facilitating the clearance of Gd(III) complexes from the body. These agents initially behave as macromolecular agents and result in superior contrast enhancement in the vasculature and tumor tissues. They can then be readily degraded in vivo into small molecular chelates that can be rapidly excretede from the body via renal filtration after the MRI examinations. Various polydisulfide Gd(III) complexes have been prepared as biodegradable macromolecular MRI contrast agents. These agents have resulted in strong contrast enhancement in the vasculature and tumor tissue in animal models with minimal long-term tissue accumulation when compared to small molecular contrast agents. Polydisulfide Gd(III) complexes are promising for further clinical development as safe and effective biodegradable macromolecular MRI contrast agents for cardiovascular and cancer imaging. The review summarizes the chemistry and properties of polydisulfide Gd(III) complexes.

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