title: Ru(II) dyads derived from 2-(1-pyrenyl)-1H-imidazo[4,5-f][1,10]phenanthroline: versatile photosensitizers for photodynamic applications.
abstract: Combining the best attributes of organic photosensitizers with those of coordination complexes is an elegant way to achieve prolonged excited state lifetimes in Ru(II) dyads. Not only do their reduced radiative and nonradiative rates provide ample time for photosensitization of reactive oxygen species at low oxygen tension but they also harness the unique properties of (3)IL states that can act as discrete units or in concert with (3)MLCT states. The imidazo[4,5-f][1,10]phenanthroline framework provides a convenient tether for linking π-expansive ligands such as pyrene to a Ru(II) scaffold, and the stabilizing coligands can fine-tune the chemical and biological properties of these bichromophoric systems. The resulting dyads described in this study exhibited nanomolar light cytotoxicities against cancer cells with photocytotoxicity indices exceeding 400 for some coligands employed. This potency extended to bacteria, where concentrations as low as 10 nM destroyed 75% of a bacterial population. Notably, these dyads remained extremely active against biofilm with light photocytotoxicities against these more resistant bacterial populations in the 10-100 nM regime. The results from this study demonstrate the versatility of these highly potent photosensitizers in destroying both cancer and bacterial cells and expand the scope of compounds that utilize low-lying (3)IL states for photobiological applications.
authors.affiliation: Department of Chemistry, Acadia University , Wolfville, NS B4P 2R6, Canada.
authors.forename: Mat
authors.initials: M
authors.lastname: Stephenson
authors.forename: Christian
authors.initials: C
authors.lastname: Reichardt
authors.forename: Mitch
authors.initials: M
authors.lastname: Pinto
authors.forename: Maria
authors.initials: M
authors.lastname: Wächtler
authors.forename: Tariq
authors.initials: T
authors.lastname: Sainuddin
authors.forename: Ge
authors.initials: G
authors.lastname: Shi
authors.forename: Huimin
authors.initials: H
authors.lastname: Yin
authors.forename: Susan
authors.initials: S
authors.lastname: Monro
authors.forename: Eric
authors.initials: E
authors.lastname: Sampson
authors.forename: Benjamin
authors.initials: B
authors.lastname: Dietzek
authors.forename: Sherri A
authors.initials: SA
authors.lastname: McFarland
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D002417:Cattle; D002470:Cell Survival / Q000187:drug effects; D004247:DNA / Q000737:chemistry / Q000187:drug effects / Q000528:radiation effects; D018922:HL-60 Cells; D006801:Humans; D010618:Phenanthrolines / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D055668:Photochemical Processes; D017319:Photosensitizing Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D017975:Ruthenium Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D013295:Streptococcus mutans / Q000187:drug effects; D013950:Thymus Gland; D014466:Ultraviolet Rays
chemical_list: D000890:Anti-Infective Agents; D000970:Antineoplastic Agents; D010618:Phenanthrolines; D017319:Photosensitizing Agents; D017975:Ruthenium Compounds; D004247:DNA