Cationic Phenylene Ethynylene Polymers and Oligomers Exhibit Efficient Antiviral Activity

A multiscale investigation was carried out to study the dark and light-enhanced bactericidal mechanisms of poly(phenylene ethynylene) (PPE)-based cationic conjugated polyelectrolytes (CPEs) and oligo-phenylene ethynylenes (OPEs). On the morphological scale, Gram-negative E. coli cells exposed to CPE and OPE compounds in the dark show damage to the cell envelope, plasma membrane, and in some cases the cytoplasm, while with UV-irradiation, E. coli sustained catastrophic damages to both the cell envelope and cytoplasm. In contrast, the Gram-positive S. epi bacteria appeared intact when exposed to CPE and OPE compounds in the dark but showed damages to the cell envelope with UV-irradiation. To better understand the molecular basis of CPE and OPE induced morphological changes and damages to bacteria, we investigated the effect of these compounds on model bacterial plasma membrane, and bacterial proteins and plasmid DNA. Measurements of dark membrane perturbation activity of the CPEs and OPEs using model lipid membranes support a carpet or detergent-like mechanism by which the antimicrobial compounds induce membrane collapse and phase transitions. Under UV-irradiation, E. coli bacteria exposed to CPEs and OPEs showed covalent modifications and damages to both cellular protein and plasmid DNA, likely through oxidative pathways mediated by singlet oxygen and subsequent reactive oxygen species sensitized by the CPE and OPE compounds. Our finding thus show that the antimicrobial polymers and oligomers exert toxicity towards Gram-negative bacteria by disrupting the morphology and structures of cell envelope and cytoplasm, including cellular components such as proteins and DNA while exert toxicity towards Gram-positive bacteria by binding to and disrupting just the cell wall.

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“…UVA (centered at ~350 nm) and UV-420 (centered at ~420 nm) were used to irradiate OPEs and CPEs, respectively. 8 …”

Section: Experimental Methodsmentioning

confidence: 99%

Understanding the Dark and Light-Enhanced Bactericidal Action of Cationic Conjugated Polyelectrolytes and Oligomers

Jett²,

et al. 2013

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“…LZC-420 (centered at ∼420 nm) and UVA (centered at ∼350 nm) were used to irradiate CPEs and OPEs, respectively. 4 The sporicidal activity of the CPEs and OPEs (30 μg/mL) were evaluated against the asci (ATCC 204722) with or without germination in the dark or under UV-irradiation (10 lamps in the photoreactor) for 60 min. The ability of a CPE or an OPE to inactivate vegetative cells and spores was determined by the plate counting method and was calculated as log (N o /N), where N is the number of colony forming units (CFU) of the yeast solution after exposure to a CPE or an OPE and N o is the CFU of a control (without biocidal material or UV-irradiation).…”

Section: ■ Experimental Methodsmentioning

confidence: 99%

Antimicrobial Activity of Cationic Conjugated Polyelectrolytes and Oligomers against Saccharomyces cerevisiae Vegetative Cells and Ascospores

Wang

Y.²,

Natvig³

et al. 2013

ACS Appl. Mater. Interfaces

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The antifungal activities of poly(phenylene ethynylene) (PPE)-based cationic conjugated polyelectrolytes (CPEs) and oligo-phenylene ethynylenes (OPEs) were investigated using Saccharomyces cerevisiae (S. cerevisiae) as a model pathogen. The effect of the CPE and OPE materials on the vegetative cells and ascospores were tested in the dark or with UV-irradiation. A number of the tested polymers and oligomers significantly reduced the viability of the vegetative yeast cells in the dark, with activities exceeding the commonly used antibiotic Amphotericin B. With UV-irradiation, all of the tested CPEs and OPEs exhibited potent antifungal activities and completely inactivated the yeast cells. In particular, the oligomeric EO-OPE-1(Th, C2) strongly inactivates ascospores with UV-light at a dose level lower than sporicidal agents reported in the literature. Under conditions that promote spore germination, the CPEs and OPEs show efficient activities against the germinated spores. The protein-enriched outer envelope of yeast cells and germinated ascospores appears to serve as a main target for the CPE and OPE antimicrobial materials.

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“…These polymers were found to be highly effective in the presence of light by forming and releasing efficiently sensitize singlet oxygen ( 1 O 2 ), but they were also effective in the dark, because of their AMP mimicking structure [67]. The singlet oxygen formation also gave the polymer antiviral properties [68].…”

Section: Biocide-releasing Polymersmentioning

confidence: 99%

Antimicrobial Polymers in Solution and on Surfaces: Overview and Functional Principles

2012

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Abstract:The control of microbial infections is a very important issue in modern society. In general there are two ways to stop microbes from infecting humans or deteriorating materials-disinfection and antimicrobial surfaces. The first is usually realized by disinfectants, which are a considerable environmental pollution problem and also support the development of resistant microbial strains. Antimicrobial surfaces are usually designed by impregnation of materials with biocides that are released into the surroundings whereupon microbes are killed. Antimicrobial polymers are the up and coming new class of disinfectants, which can be used even as an alternative to antibiotics in some cases. Interestingly, antimicrobial polymers can be tethered to surfaces without losing their biological activity, which enables the design of surfaces that kill microbes without releasing biocides. The present review considers the working mechanisms of antimicrobial polymers and of contact-active antimicrobial surfaces based on examples of recent research as well as on multifunctional antimicrobial materials.

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Cationic Phenylene Ethynylene Polymers and Oligomers Exhibit Efficient Antiviral Activity

Cited by 70 publications

References 26 publications

Understanding the Dark and Light-Enhanced Bactericidal Action of Cationic Conjugated Polyelectrolytes and Oligomers

Understanding the Dark and Light-Enhanced Bactericidal Action of Cationic Conjugated Polyelectrolytes and Oligomers

Antimicrobial Activity of Cationic Conjugated Polyelectrolytes and Oligomers against Saccharomyces cerevisiae Vegetative Cells and Ascospores

Antimicrobial Polymers in Solution and on Surfaces: Overview and Functional Principles

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