title: Extended rhodamine photosensitizers for photodynamic therapy of cancer cells.
abstract: Extended thio- and selenorhodamines with a linear or angular fused benzo group were prepared. The absorption maxima for these compounds fell between 640 and 700nm. The extended rhodamines were evaluated for their potential as photosensitizers for photodynamic therapy in Colo-26 cells. These compounds were examined for their photophysical properties (absorption, fluorescence, and ability to generate singlet oxygen), for their dark and phototoxicity toward Colo-26 cells, and for their co-localization with mitochondrial-specific agents in Colo-26 and HUT-78 cells. The angular extended rhodamines were effective photosensitizers toward Colo-26 cells with 1.0Jcm(-2) laser light delivered at λmax±2nm with values of EC50 of (2.8±0.4)×10(-7)M for sulfur-containing analogue 6-S and (6.4±0.4)×10(-8)M for selenium-containing analogue 6-Se. The linear extended rhodamines were effective photosensitizers toward Colo-26 cells with 5 and 10Jcm(-2) of broad-band light (EC50's⩽2.4×10(-7)M).
authors.affiliation: Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, NY 14260-3000, United States. Electronic address: kdavies@buffalo.edu.
authors.forename: Kellie S
authors.initials: KS
authors.lastname: Davies
authors.affiliation: Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, NY 14260-3000, United States. Electronic address: mklinder@buffalo.edu.
authors.forename: Michelle K
authors.initials: MK
authors.lastname: Linder
authors.affiliation: Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, NY 14260-3000, United States. Electronic address: markkrym@buffalo.edu.
authors.forename: Mark W
authors.initials: MW
authors.lastname: Kryman
authors.affiliation: Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, NY 14260-3000, United States; Institute for Lasers, Photonics and Biophotonics, Department of Chemistry, State University of New York, Buffalo, NY 14260, United States. Electronic address: mdetty@buffalo.edu.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Detty
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D008027:Light; D008247:Lysosomes / Q000378:metabolism; D051379:Mice; D008928:Mitochondria / Q000378:metabolism; D016566:Organoselenium Compounds / Q000138:chemical synthesis / Q000494:pharmacology*; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D012235:Rhodamines / Q000138:chemical synthesis / Q000494:pharmacology*
chemical_list: D005456:Fluorescent Dyes; D016566:Organoselenium Compounds; D017319:Photosensitizing Agents; D012235:Rhodamines
keywords: Extended rhodamines; Photodynamic therapy; Photosensitizers