A Supramolecular Approach for Modulated Photoprotection, Lysosomal Delivery, and Photodynamic Activity of a Photosensitizer

Indranil Roy, Sharan Bobbala, Ryan M. Young, Yassine Beldjoudi, Minh T. Nguyen, M. Mustafa Cetin, James A. Cooper, Sean Allen, Ommid Anamimoghadam, Evan A. Scott, Michael R. Wasielewski, J. Fraser Stoddart*

*Corresponding author for this work

Research output: Contribution to journalArticle

2 Scopus citations


Prompted by a knowledge of the photoprotective mechanism operating in photosystem supercomplexes and bacterial antenna complexes by pigment binding proteins, we have appealed to a boxlike synthetic receptor (ExBox·4Cl) that binds a photosensitizer, 5,15-diphenylporphyrin (DPP), to provide photoprotection by regulating light energy. The hydrophilic ExBox4+ renders DPP soluble in water and modulates the phototoxicity of DPP by trapping it in its cavity and releasing it when required. While trapping removes access to the DPP triplet state, a pH-dependent release of diprotonated DPP (DPPH2 2+) restores the triplet deactivation pathway, thereby activating its ability to generate reactive oxygen species. We have employed the ExBox4+-bound DPP complex (ExBox4+⊃DPP) for the safe delivery of DPP into the lysosomes of cancer cells, imaging the cells by utilizing the fluorescence of the released DPPH2 2+ and regulating photodynamic therapy to kill cancer cells with high efficiency.

Original languageEnglish (US)
Pages (from-to)12296-12304
Number of pages9
JournalJournal of the American Chemical Society
Issue number31
StatePublished - Aug 7 2019


ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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