Imidazole metalloporphyrins as photosensitizers for photodynamic therapy: Role of molecular charge, central metal and hydroxyl radical production

Pawel Mroz, Jayeeta Bhaumik, Dilek K. Dogutan, Zarmeneh Aly, Zahra Kamal, Laiqua Khalid, Hooi Ling Kee, David F. Bocian, Dewey Holten, Jonathan S. Lindsey, Michael R. Hamblin

Research output: Contribution to journalArticlepeer-review

86 Scopus citations

Abstract

The in vitro photodynamic therapy activity of four imidazole-substituted metalloporphyrins has been studied using human (HeLa) and mouse (CT26) cancer cell lines: an anionic Zn porphyrin and a homologous series of three cationic Zn, Pd or InCl porphyrins. A dramatic difference in phototoxicity was found: Pd cationic > InCl cationic > Zn cationic > Zn anionic. HeLa cells were more susceptible than CT26 cells. Induction of apoptosis was demonstrated using a fluorescent caspase assay. The anionic Zn porphyrin localized in lysosomes while the cationic Zn porphyrin localized in lysosomes and mitochondria, as assessed by fluorescence microscopy. Studies using fluorescent probes suggested that the cationic Pd porphyrin produced more hydroxyl radicals as the reactive oxygen species. Thus, the cationic Pd porphyrin has high potential as a photosensitizer and gives insights into characteristics for improved molecular designs.

Original languageEnglish (US)
Pages (from-to)63-76
Number of pages14
JournalCancer Letters
Volume282
Issue number1
DOIs
StatePublished - Sep 8 2009
Externally publishedYes

Keywords

  • Apoptosis
  • Fluorescence microscopy
  • Hydroxyl radicals
  • Metalloporphyrins
  • Photophysics
  • Phototoxicity
  • Reactive oxygen species
  • Structure function relationship

Fingerprint Dive into the research topics of 'Imidazole metalloporphyrins as photosensitizers for photodynamic therapy: Role of molecular charge, central metal and hydroxyl radical production'. Together they form a unique fingerprint.

Cite this