Cargando…
The Antimicrobial Photoinactivation Effect on Escherichia coli through the Action of Inverted Cationic Porphyrin–Cyclodextrin Conjugates
Photodynamic action has been used for diverse biomedical applications, such as treating a broad range of bacterial infections. Based on the combination of light, dioxygen, and photosensitizer (PS), the photodynamic inactivation (PDI) approach led to the formation of reactive oxygen species (ROS) and...
Autores principales: | , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2022
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9026372/ https://www.ncbi.nlm.nih.gov/pubmed/35456769 http://dx.doi.org/10.3390/microorganisms10040718 |
_version_ | 1784691104232243200 |
---|---|
author | Ribeiro, Cláudia P. S. Faustino, Maria A. F. Almeida, Adelaide Lourenço, Leandro M. O. |
author_facet | Ribeiro, Cláudia P. S. Faustino, Maria A. F. Almeida, Adelaide Lourenço, Leandro M. O. |
author_sort | Ribeiro, Cláudia P. S. |
collection | PubMed |
description | Photodynamic action has been used for diverse biomedical applications, such as treating a broad range of bacterial infections. Based on the combination of light, dioxygen, and photosensitizer (PS), the photodynamic inactivation (PDI) approach led to the formation of reactive oxygen species (ROS) and represented a non-invasive, non-toxic, repeatable procedure for pathogen photoinactivation. To this end, different tetrapyrrolic macrocycles, such as porphyrin (Por) dyes, have been used as PSs for PDI against microorganisms, mainly bacteria. Still, there is significant room for improvement, especially new PS molecules. Herein, unsymmetrical new pyridinone (3–5) and thiopyridyl Pors (7) were prepared with α-, β-, or γ-cyclodextrin (CD) units, following their quaternization to perform the corresponding free-base Pors (3a–5a and 7a), and were compared with the already-known Pors 6a and 8a, both bearing thiopyridinium and CD units. These water-soluble porphyrins were evaluated as PSs, and their photophysical and photochemical properties and photodynamic effects on E. coli were assessed. The presence of one CD unit and three positive charges on the Por structure (3a–5a and 7a) enhanced their aqueous solubility. The photoactivity of the cationic Pors 3a–5a and 6a–8a ensured their potential against the Gram-negative bacterium E. coli. Within each series of methoxypyridinium vs thiopyridinium dyes, the best PDI efficiency was achieved for 5a with a bacterial viability reduction of 3.5 log(10) (50 mW cm(−2), 60 min of light irradiation) and for 8a with a total bacterial viability reduction (>8 log(10), 25 mW cm(−2), 30 min of light irradiation). Here, the presence of the methoxypyridinium units is less effective against E. coli when compared with the thiopyridinium moieties. This study allows for the conclusion that the peripheral charge position, quaternized substituent type/CD unit, and affinity to the outer bacterial structures play an important role in the photoinactivation efficiency of E. coli, evidencing that these features should be further addressed in the pursuit for optimised PS for the antimicrobial PDI of pathogenic microorganisms. |
format | Online Article Text |
id | pubmed-9026372 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-90263722022-04-23 The Antimicrobial Photoinactivation Effect on Escherichia coli through the Action of Inverted Cationic Porphyrin–Cyclodextrin Conjugates Ribeiro, Cláudia P. S. Faustino, Maria A. F. Almeida, Adelaide Lourenço, Leandro M. O. Microorganisms Article Photodynamic action has been used for diverse biomedical applications, such as treating a broad range of bacterial infections. Based on the combination of light, dioxygen, and photosensitizer (PS), the photodynamic inactivation (PDI) approach led to the formation of reactive oxygen species (ROS) and represented a non-invasive, non-toxic, repeatable procedure for pathogen photoinactivation. To this end, different tetrapyrrolic macrocycles, such as porphyrin (Por) dyes, have been used as PSs for PDI against microorganisms, mainly bacteria. Still, there is significant room for improvement, especially new PS molecules. Herein, unsymmetrical new pyridinone (3–5) and thiopyridyl Pors (7) were prepared with α-, β-, or γ-cyclodextrin (CD) units, following their quaternization to perform the corresponding free-base Pors (3a–5a and 7a), and were compared with the already-known Pors 6a and 8a, both bearing thiopyridinium and CD units. These water-soluble porphyrins were evaluated as PSs, and their photophysical and photochemical properties and photodynamic effects on E. coli were assessed. The presence of one CD unit and three positive charges on the Por structure (3a–5a and 7a) enhanced their aqueous solubility. The photoactivity of the cationic Pors 3a–5a and 6a–8a ensured their potential against the Gram-negative bacterium E. coli. Within each series of methoxypyridinium vs thiopyridinium dyes, the best PDI efficiency was achieved for 5a with a bacterial viability reduction of 3.5 log(10) (50 mW cm(−2), 60 min of light irradiation) and for 8a with a total bacterial viability reduction (>8 log(10), 25 mW cm(−2), 30 min of light irradiation). Here, the presence of the methoxypyridinium units is less effective against E. coli when compared with the thiopyridinium moieties. This study allows for the conclusion that the peripheral charge position, quaternized substituent type/CD unit, and affinity to the outer bacterial structures play an important role in the photoinactivation efficiency of E. coli, evidencing that these features should be further addressed in the pursuit for optimised PS for the antimicrobial PDI of pathogenic microorganisms. MDPI 2022-03-26 /pmc/articles/PMC9026372/ /pubmed/35456769 http://dx.doi.org/10.3390/microorganisms10040718 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Ribeiro, Cláudia P. S. Faustino, Maria A. F. Almeida, Adelaide Lourenço, Leandro M. O. The Antimicrobial Photoinactivation Effect on Escherichia coli through the Action of Inverted Cationic Porphyrin–Cyclodextrin Conjugates |
title | The Antimicrobial Photoinactivation Effect on Escherichia coli through the Action of Inverted Cationic Porphyrin–Cyclodextrin Conjugates |
title_full | The Antimicrobial Photoinactivation Effect on Escherichia coli through the Action of Inverted Cationic Porphyrin–Cyclodextrin Conjugates |
title_fullStr | The Antimicrobial Photoinactivation Effect on Escherichia coli through the Action of Inverted Cationic Porphyrin–Cyclodextrin Conjugates |
title_full_unstemmed | The Antimicrobial Photoinactivation Effect on Escherichia coli through the Action of Inverted Cationic Porphyrin–Cyclodextrin Conjugates |
title_short | The Antimicrobial Photoinactivation Effect on Escherichia coli through the Action of Inverted Cationic Porphyrin–Cyclodextrin Conjugates |
title_sort | antimicrobial photoinactivation effect on escherichia coli through the action of inverted cationic porphyrin–cyclodextrin conjugates |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9026372/ https://www.ncbi.nlm.nih.gov/pubmed/35456769 http://dx.doi.org/10.3390/microorganisms10040718 |
work_keys_str_mv | AT ribeiroclaudiaps theantimicrobialphotoinactivationeffectonescherichiacolithroughtheactionofinvertedcationicporphyrincyclodextrinconjugates AT faustinomariaaf theantimicrobialphotoinactivationeffectonescherichiacolithroughtheactionofinvertedcationicporphyrincyclodextrinconjugates AT almeidaadelaide theantimicrobialphotoinactivationeffectonescherichiacolithroughtheactionofinvertedcationicporphyrincyclodextrinconjugates AT lourencoleandromo theantimicrobialphotoinactivationeffectonescherichiacolithroughtheactionofinvertedcationicporphyrincyclodextrinconjugates AT ribeiroclaudiaps antimicrobialphotoinactivationeffectonescherichiacolithroughtheactionofinvertedcationicporphyrincyclodextrinconjugates AT faustinomariaaf antimicrobialphotoinactivationeffectonescherichiacolithroughtheactionofinvertedcationicporphyrincyclodextrinconjugates AT almeidaadelaide antimicrobialphotoinactivationeffectonescherichiacolithroughtheactionofinvertedcationicporphyrincyclodextrinconjugates AT lourencoleandromo antimicrobialphotoinactivationeffectonescherichiacolithroughtheactionofinvertedcationicporphyrincyclodextrinconjugates |