Deuterated Indocyanine Green (ICG) with Extended Aqueous Storage Shelf-Life: Chemical and Clinical Implications



Indocyanine Green (ICG) is a clinically approved near-infrared fluorescent dye that is used extensively for various imaging and diagnostic procedures. One drawback with ICG is its instability in water, which means that reconstituted clinical doses have to be used very shortly after preparation. Two deuterated versions of ICG were prepared with deuterium atoms on the heptamethine chain, and the spectral, physiochemical, and photostability properties were quantified. A notable mechanistic finding is that self-aggregation of ICG in water strongly favors dye degradation by a photochemical oxidative dimerization reaction that gives a nonfluorescent product. Storage stability studies showed that replacement of C􀀀 H with C􀀀 D decreased the dimerization rate constant by a factor of 3.1, and it is likely that many medical and preclinical procedures will benefit from the longer shelf-lives of these two deuterated ICG dyes. The discovery that ICG self-aggregation promotes photoinduced electron transfer can be exploited as a new paradigm for next-generation photodynamic therapies.


Attribute NameValues
  • Dong-Hao Li

  • Bradley D. Smith

Journal or Work Title
  • Chemistry: A European Journal

  • 27

First Page
  • 14535

Last Page
  • 14542

Number of Pages
  • 7

Publication Date
  • 2021-09

  • Advanced Molecular Imaging HT Instrument

  • Wiley VCH GmbH

Date Created
  • 2022-11-18

Bibliographic Citation
  • English

Departments and Units
Record Visibility Public
Content License
  • All rights reserved

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