An Iridium Complex as an AIE-active Photosensitizer for Image-guided Photodynamic Therapy

Chem Asian J. 2021 Jul 5;16(13):1780-1785. doi: 10.1002/asia.202100291. Epub 2021 May 26.

Abstract

Image-guided photodynamic therapy (PDT) has received growing attention due to its non-invasiveness and precise controllability. However, the PDT efficiency of most photosensitizers are decreased in living system due to the aggregation-caused singlet oxygen (1 O2 ) generation decreasing. Herein, we present an Iridium (III) pyridylpyrrole complex (Ir-1) featuring of aggregation-induced emission (AIE) and 1 O2 generation characteristics for image-guided PDT of cancer. Ir-1 aqueous solution exhibits bright red phosphorescence peaked at 630 nm, large Stokes shift of 227 nm, and good 1 O2 generation ability. The 1 O2 generating rate of Ir-1 in EtOH/water mixture solution is 2.3 times higher than that of Rose Bengal. In vitro experimental results revealed that Ir-1 has better biocompatibility and higher phototoxicity compared with clinically used photosensitizers (Rose Bengal and Ce6), suggesting that Ir-1 can serve as a photosensitizer for image-guided PDT of cancer.

Keywords: aggregation-induced emission; iridium (III) pyridylpyrrole complex; photodynamic therapy.

MeSH terms

  • Animals
  • Crystallization
  • Iridium / chemistry*
  • Mice
  • Models, Molecular
  • Molecular Structure
  • Neoplasms / therapy*
  • Neoplasms, Experimental / therapy
  • Photochemotherapy*
  • Photosensitizing Agents / chemistry*
  • Photosensitizing Agents / pharmacology*

Substances

  • Photosensitizing Agents
  • Iridium