Synthesis and Evaluation of New Generation Cross-Bridged Bifunctional Chelator for 64Cu Radiotracers

详细信息    查看全文

• 作者：Ajit V. Dale ; Gwang Il An ; Darpan N. Pandya ; Yeong Su Ha ; Nikunj Bhatt ; Nisarg Soni ; Hochun Lee ; Heesu Ahn ; Swarbhanu Sarkar ; Woonghee Lee ; Phuong Tu Huynh ; Jung Young Kim ; Mi-Ri Gwon ; Sung Hong Kim ; Jae Gyu Park ; Young-Ran Yoon ; Jeongsoo Yoo
• 刊名：Inorganic Chemistry
• 出版年：2015
• 出版时间：September 8, 2015
• 年：2015
• 卷：54
• 期：17
• 页码：8177-8186
• 全文大小：431K
• ISSN：1520-510X

文摘

Bifunctional chelators have been successfully used to construct ⁶⁴Cu-labeled radiopharmaceuticals. Previously reported chelators with cross-bridged cyclam backbones have various essential features such as high stability of the copper(II) complex, high efficiency of radiolabeling at room temperature, and good biological inertness of the radiolabeled complex, along with rapid body clearance. Here, we report a new generation propylene-cross-bridged chelator with hybrid acetate/phosphonate pendant groups (PCB-TE1A1P) developed with the aim of combining these key properties in a single chelator. The PCB-TE1A1P was synthesized from cyclam with good overall yield. The Cu(II) complex of our chelator showed good robustness in kinetic stability evaluation experiments, such as acidic decomplexation and cyclic voltammetry studies. The Cu(II) complex of PCB-TE1A1P remained intact under highly acidic conditions (12 M HCl, 90 掳C) for 8 d and showed quasi-reversible reduction/oxidation peaks at 鈭?.77 V in electrochemical studies. PCB-TE1A1P was successfully radiolabeled with ⁶⁴Cu ions in an acetate buffer at 60 掳C within 60 min. The electrophoresis study revealed that the ⁶⁴Cu-PCB-TE1A1P complex has net negative charge in aqueous solution. The biodistribution and in vivo stability study profiles of ⁶⁴Cu-PCB-TE1A1P indicated that the radioactive complex was stable under physiological conditions and cleared rapidly from the body. A whole body positron emission tomography (PET) imaging study further confirmed high in vivo stability and fast clearance of the complex in mouse models. In conclusion, PCB-TE1A1P has good potential as a bifunctional chelator for ⁶⁴Cu-based radiopharmaceuticals, especially those involving peptides.