Copper-64 Labeled PEGylated Exosomes for In Vivo Positron Emission Tomography and Enhanced Tumor Retention

Sixiang Shi, Tingting Li, Xiaofei Wen, Sherry Y. Wu, Chiyi Xiong, Jun Zhao, Victor R. Lincha, Diana S. Chow, Yiyao Liu, Anil K. Sood, Chun Li

Research output: Journal article publicationJournal articleAcademic researchpeer-review

67 Citations (Scopus)


Exosomes have attracted tremendous attention due to their important role in physiology, pathology, and oncology, as well as promising potential in biomedical applications. Although great efforts have been dedicated to investigating their biological properties and applications as natural cancer drug-delivery systems, the systemic biodistribution of exosomes remains underexplored. In addition, exosome-based drug delivery is inevitably hindered by the robust liver clearance, leading to suboptimal tumor retention and therapeutic efficiency. In this study, we report one of the first examples using in vivo positron emission tomography (PET) for noninvasive monitoring of copper-64 (64Cu)-radiolabeled polyethylene glycol (PEG)-modified exosomes, achieving excellent imaging quality and quantitative measurement of blood residence and tumor retention. PEGylation not only endowed exosomes with a superior pharmacokinetic profile and great accumulation in the tumor versus traditionally reported native exosomes but also reduced premature hepatic sequestration and clearance of exosomes, findings that promise enhanced therapeutic delivery efficacy and safety in future studies. More importantly, this study provides important guidelines about surface engineering, radiochemistry, and molecular imaging in obtaining accurate and quantitative biodistribution information on exosomes, which may benefit future exploration in the realm of exosomes.

Original languageEnglish
JournalBioconjugate Chemistry
Early online date27 Sept 2019
Publication statusPublished - 16 Oct 2019
Externally publishedYes

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Biomedical Engineering
  • Pharmacology
  • Pharmaceutical Science
  • Organic Chemistry


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