title: Improving photodynamic inactivation of bacteria in dentistry: highly effective and fast killing of oral key pathogens with novel tooth-colored type-II photosensitizers.
abstract: Increasing antibiotic resistances in microorganisms create serious problems in public health. This demands alternative approaches for killing pathogens to supplement standard treatment methods. Photodynamic inactivation of bacteria (PIB) uses light activated photosensitizers (PS) to generate reactive oxygen species immediately upon illumination, inducing lethal phototoxicity. Positively charged phenalen-1-one derivatives are a new generation of PS for light-mediated killing of pathogens with outstanding singlet oxygen quantum yield ΦΔ of >97%. Upon irradiation with a standard photopolymerizer light (bluephase C8, 1260 ± 50 mW/cm(2)) the PS showed high activity against the oral key pathogens Enterococcus faecalis, Actinomyces naeslundii, Streptococcus mutans, and Aggregatibacter actinomycetemcomitans. At a concentration of 10 μM, a maximum efficacy of more than 6 log10 steps (≥ 99.9999%) of bacteria killing is reached in less than 1 min (light dose 50 J/cm(2)) after one single treatment. The pyridinium substituent as positively charged moiety is especially advantageous for antimicrobial action.
authors.affiliation: Department of Organic Chemistry, University of Regensburg , Regensburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Späth
authors.forename: Christoph
authors.initials: C
authors.lastname: Leibl
authors.forename: Fabian
authors.initials: F
authors.lastname: Cieplik
authors.forename: Karin
authors.initials: K
authors.lastname: Lehner
authors.forename: Johannes
authors.initials: J
authors.lastname: Regensburger
authors.forename: Karl-Anton
authors.initials: KA
authors.lastname: Hiller
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Bäumler
authors.forename: Gottfried
authors.initials: G
authors.lastname: Schmalz
authors.forename: Tim
authors.initials: T
authors.lastname: Maisch
mesh_terms: D000190:Actinomyces / Q000187:drug effects / Q000378:metabolism; D016976:Aggregatibacter actinomycetemcomitans / Q000187:drug effects / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D003116:Color; D004355:Drug Stability; D013293:Enterococcus faecalis / Q000187:drug effects / Q000378:metabolism; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000378:metabolism; D006094:Gram-Positive Bacteria / Q000187:drug effects* / Q000378:metabolism; D010518:Periodontitis / Q000382:microbiology; D043803:Phenalenes / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D026082:Singlet Oxygen / Q000378:metabolism; D013295:Streptococcus mutans / Q000187:drug effects / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D043803:Phenalenes; D017319:Photosensitizing Agents; D026082:Singlet Oxygen