Effect of Sodium Chloride on Aggregation of Merocyanine 540 and Photosensitized Inactivation of Staphylococcus aureus and Pseudomonas aeruginosa

Ta, Shmigol'; Va, Bekhalo; CIe, Sysolyatina; Ev, Nagurskaya; Sа, Ermolaeva; Ay, Potapenko

doi:10.32607/20758251-2011-3-4-107-113

Cited by 2 publications

(1 citation statement)

References 14 publications

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“…Unlike indocyanine green, that is a cationic derivative of cyanine, absorbing at 800 nm, Merocyanine 540 is neutral and shows a significant blue shift in absorption spectrum (555 nm). The efficiency as PS is not very high, both on planktonic cultures [ 217 ] and biofilms, requiring a significant light fluence and showing a limited radiation penetration [ 218 ].…”

Section: An Overview On Antimicrobial Photosensitizersmentioning

confidence: 99%

Photodynamic treatment of pathogens

2022

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The current viral pandemic has highlighted the compelling need for effective and versatile treatments, that can be quickly tuned to tackle new threats, and are robust against mutations. Development of such treatments is made even more urgent in view of the decreasing effectiveness of current antibiotics, that makes microbial infections the next emerging global threat. Photodynamic effect is one such method. It relies on physical processes proceeding from excited states of particular organic molecules, called photosensitizers, generated upon absorption of visible or near infrared light. The excited states of these molecules, tailored to undergo efficient intersystem crossing, interact with molecular oxygen and generate short lived reactive oxygen species (ROS), mostly singlet oxygen. These species are highly cytotoxic through non-specific oxidation reactions and constitute the basis of the treatment. In spite of the apparent simplicity of the principle, the method still has to face important challenges. For instance, the short lifetime of ROS means that the photosensitizer must reach the target within a few tens nanometers, which requires proper molecular engineering at the nanoscale level. Photoactive nanostructures thus engineered should ideally comprise a functionality that turns the system into a theranostic means, for instance, through introduction of fluorophores suitable for nanoscopy. We discuss the principles of the method and the current molecular strategies that have been and still are being explored in antimicrobial and antiviral photodynamic treatment.

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Section: An Overview On Antimicrobial Photosensitizersmentioning

confidence: 99%

Photodynamic treatment of pathogens

2022

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Antimicrobial Photosensitizers: Drug Discovery Under the Spotlight

Yin¹,

Hamblin

2015

CMC

110

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Although photodynamic therapy (PDT) was discovered over a hundred years ago by its ability to destroy microorganisms, it has been developed mainly as a cancer therapy. In recent years, due to the inexorable rise in multi-antibiotic resistant strains of pathogens, PDT is being considered as a versatile antimicrobial approach to which microbial cells will not be able to develop resistance. The goal of this review is to survey the different classes of chemical compounds that have been tested as antimicrobial photosensitizers. Some of these compounds have been known for many years, while others have been rationally designed based on recently discovered structural principles. Tetrapyrrole-based compounds (some of which are approved as cancer therapies) that efficiently generate singlet oxygen are more efficient and broad-spectrum when they bear cationic charges, As the macrocycle structure moves from porphyrins to chlorins to phthalocyanines to bacteriochlorins the long wavelength absorption moves to the near-infrared where tissue penetration is better. Four main types of natural products have been tested: curcumin, riboflavin, hypericin and psoralens. Phenothiazinium dyes, such as methylene blue and toluidine blue, have been tested, and some are clinically approved. A variety of non-phenothiazinium dyes with xanthene, triarylmethane and indocyanine structures have also been tested. New ring structures based on BODIPY, squaraine and fullerene cages can also mediate antimicrobial PDT. Finally the process of photocatalysis using titanium dioxide can also have medical uses. Designing new antimicrobial photosensitizers is likely to keep chemists engaged for a long time to come.

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Effect of Sodium Chloride on Aggregation of Merocyanine 540 and Photosensitized Inactivation of Staphylococcus aureus and Pseudomonas aeruginosa

Cited by 2 publications

References 14 publications

Photodynamic treatment of pathogens

Photodynamic treatment of pathogens

Antimicrobial Photosensitizers: Drug Discovery Under the Spotlight

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