title: Light and dark biocidal activity of cationic poly(arylene ethynylene) conjugated polyelectrolytes.
abstract: In this paper we report a study of cationic poly(arylene ethynylene) conjugated polyelectrolytes. The objective of the study was to compare the behavior of a polymer where a thiophene has replaced a phenyl ring in poly(phenylene ethynylene) polycations (PPE) previously investigated. Properties of solution phase and physisorbed suspensions of the polymer on microspheres were investigated. The photophysical properties of the polymer are evaluated and used to understand the striking differences in biocidal activity compared to the PPE polymers previously examined. The principal findings are that the thiophene polymer has remarkable dark biocidal activity against Pseudomonas aeruginosa strain PAO1 but very little light-activated activity. The low light-activated biocidal activity of the thiophene polymer is attributed to a highly aggregated state of the polymer in aqueous solutions and on microspheres as a physisorbed coating. This results in low triplet yields and a very poor sensitization of singlet oxygen and other reactive oxygen intermediates. The highly effective dark biocidal activity of the thiophene-containing polymers is attributed to its high lipophilicity and the presence of accessible quaternary ammonium groups. The difference in behavior among the polymers compared provides insights into the mechanism of the dark process and indicates that aggregation of polymer can reduce light activated biocidal activity by suppressing singlet oxygen generation.
authors: Center for Biomedical Engineering and Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, NM 87131-0001, USA.
authors: Thomas S
authors: TS
authors: Corbitt
authors: Liping
authors: L
authors: Ding
authors: Eunkyung
authors: E
authors: Ji
authors: Linnea K
authors: LK
authors: Ista
authors: Katsu
authors: K
authors: Ogawa
authors: Gabriel P
authors: GP
authors: Lopez
authors: Kirk S
authors: KS
authors: Schanze
authors: David G
authors: DG
authors: Whitten
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D004573:Electrolytes / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D008027:Light; D050296:Microbial Viability; D008863:Microspheres; D015394:Molecular Structure; D010715:Phosphatidylglycerols / Q000737:chemistry; D055668:Photochemical Processes; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000166:cytology / Q000187:drug effects*; D026082:Singlet Oxygen / Q000737:chemistry; D013876:Thiophenes / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D004573:Electrolytes; D010715:Phosphatidylglycerols; D011108:Polymers; D013876:Thiophenes; C473966:poly(phenylene ethynylene); D026082:Singlet Oxygen; C051388:1,2-dioleoyl-sn-glycero-3-phosphoglycerol