title: Cationic Oligo(thiophene ethynylene) with Broad-Spectrum and High Antibacterial Efficiency under White Light and Specific Biocidal Activity against S. aureus in Dark.
abstract: We designed and synthesized a novel oligo(thiophene ethynylene) (OTE) to investigate the antibacterial activities against Gram-positive (Staphylococcus aureus and Staphylococcus epidermidis) and Gram-negative (Ralstonia solanacearum and Escherichia coli) bacteria in vitro by photodynamic therapy (PDT). Notably, OTE presents broad-spectrum and greatly high antibacterial activities after white light irradiation at nanogram per milliliter concentrations. The half inhibitory concentrations (IC50) values obtained for S. aureus, S. epidermidis, E. coli, and R. solanacearum are 8, 13, 24, and 52 ng/mL after illumination for 30 min, respectively, which are lower than that of other PDT agents. Interestingly, OTE shows the specific and very strong dark killing capability against S. aureus at the concentration of 180 ng/mL for 30 min, which is the highest efficiency biocide against S. aureus without the need of irradiation to date. The antibacterial mechanism investigated demonstrated that reactive oxygen species or singlet-oxygen generated by OTE kills bacteria irreversibly upon white light irradiation, and OTE as a v-type oligomer exerts its toxicity directly on destroying bacterial cytoplasmic membrane in the dark. Importantly, the OTE shows no cell cytotoxicity and excellent biocompatibility. The results indicate that it is potential to provide versatile applications in the efficient control of pathogenic organisms and specific application for killing S. aureus.
authors.affiliation: Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University , Xi'an 710062, P. R. China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University , Xi'an 710062, P. R. China.
authors.forename: Junting
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University , Xi'an 710062, P. R. China.
authors.forename: Xiaoqian
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University , Xi'an 710062, P. R. China.
authors.forename: Zhengping
authors.initials: Z
authors.lastname: Li
authors.affiliation: Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University , Xi'an 710062, P. R. China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Tang
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002412:Cations; D002470:Cell Survival / Q000187:drug effects; D003624:Darkness; D004926:Escherichia coli / Q000187:drug effects / Q000528:radiation effects; D006367:HeLa Cells; D006801:Humans; D008027:Light; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D008856:Microscopy, Fluorescence; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000528:radiation effects*; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000528:radiation effects; D013876:Thiophenes / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D002412:Cations; D000644:Quaternary Ammonium Compounds; D013876:Thiophenes; C000611687:oligo(thiophene-ethynylene)
keywords: antibiotics; conjugated oligomer; photodynamic therapy; photosensitizer; singlet oxygen