Chelator‐Free Radiolabeling of Nanographene: Breaking the Stereotype of Chelation. Issue 11 (7th February 2017)

• Record Type: Journal Article
• Authors: Shi, Sixiang; Xu, Cheng; Yang, Kai; Goel, Shreya; Valdovinos, Hector F.; Luo, Haiming; Ehlerding, Emily B.; England, Christopher G.; Cheng, Liang; Chen, Feng; Nickles, Robert J.; Liu, Zhuang; Cai, Weibo
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 11(2017)
• Page Start: 2889
• Page End: 2892
• Publication Date: 2017-02-07
• Subjects: graphene -- imaging agents -- nanoparticles -- positron emission tomography -- radiolabeling; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201610649
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Macrocyclic chelators have been widely employed in the realm of nanoparticle‐based positron emission tomography (PET) imaging, whereas its accuracy remains questionable. Here, we found that 64 Cu can be intrinsically labeled onto nanographene based on interactions between Cu and the π electrons of graphene without the need of chelator conjugation, providing a promising alternative radiolabeling approach that maintains the native in vivo pharmacokinetics of the nanoparticles. Due to abundant π bonds, reduced graphene oxide (RGO) exhibited significantly higher labeling efficiency in comparison with graphene oxide (GO) and exhibited excellent radiostability in vivo. More importantly, nonspecific attachment of 1, 4, 7‐triazacyclononane‐1, 4, 7‐triacetic acid (NOTA) on nanographene was observed, which revealed that chelator‐mediated nanoparticle‐based PET imaging has its inherent drawbacks and can possibly lead to erroneous imaging results in vivo. Abstract : Chelator‐free radiolabeling based on interactions between Cu and the π electrons of nanographene was shown, which can potentially substitute chelator‐assisted labeling. The reliability of in vivo positron emission tomography imaging is enhanced while bypassing the inherent drawbacks of conventional chelator‐based labeling.