title: Light and dark-activated biocidal activity of conjugated polyelectrolytes.
abstract: This Spotlight on Applications provides an overview of a research program that has focused on the development and mechanistic study of cationic conjugated polyelectrolytes (CPEs) that function as light- and dark-active biocidal agents. Investigation has centered on poly-(phenylene ethynylene) (PPE) type conjugated polymers that are functionalized with cationic quaternary ammonium solubilizing groups. These polymers are found to interact strongly with Gram-positive and Gram-negative bacteria, and upon illumination with near-UV and visible light act to rapidly kill the bacteria. Mechanistic studies suggest that the cationic PPE-type polymers efficiently sensitize singlet oxygen ((1)O(2)), and this cytotoxic agent is responsible for initiating the sequence of events that lead to light-activated bacterial killing. Specific CPEs also exhibit dark-active antimicrobial activity, and this is believed to arise due to interactions between the cationic/lipophilic polymers and the negatively charged outer membrane characteristic of Gram-negative bacteria. Specific results are shown where a cationic CPE with a degree of polymerization of 49 exhibits pronounced light-activated killing of E. coli when present in the cell suspension at a concentration of 1 μg mL(-1).
authors.affiliation: Department of Chemical and Nuclear Engineering and Center for Biomedical Engineering, University of New Mexico, Albuquerque, New Mexico 87131-1341, United States.
authors.forename: Eunkyung
authors.initials: E
authors.lastname: Ji
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Corbitt
authors.forename: Anand
authors.initials: A
authors.lastname: Parthasarathy
authors.forename: Kirk S
authors.initials: KS
authors.lastname: Schanze
authors.forename: David G
authors.initials: DG
authors.lastname: Whitten
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D002412:Cations / Q000737:chemistry; D004573:Electrolytes / Q000737:chemistry / Q000494:pharmacology*; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D008027:Light; D008856:Microscopy, Fluorescence; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D026082:Singlet Oxygen / Q000737:chemistry / Q000633:toxicity; D014466:Ultraviolet Rays
chemical_list: D000890:Anti-Infective Agents; D002412:Cations; D004573:Electrolytes; D011108:Polymers; D000644:Quaternary Ammonium Compounds; C473966:poly(phenylene ethynylene); D026082:Singlet Oxygen