Photodynamic inactivation mediated by methylene blue or chlorin e6 against Streptococcus mutans biofilm.
Biofilm
Chlorin e6
Lactic acid production
Methylene blue
Photodynamic inactivation
Streptococcus mutans
Journal
Photodiagnosis and photodynamic therapy
ISSN: 1873-1597
Titre abrégé: Photodiagnosis Photodyn Ther
Pays: Netherlands
ID NLM: 101226123
Informations de publication
Date de publication:
Sep 2020
Sep 2020
Historique:
received:
30
09
2019
revised:
21
03
2020
accepted:
04
05
2020
pubmed:
15
5
2020
medline:
15
5
2021
entrez:
15
5
2020
Statut:
ppublish
Résumé
An appropriate photosensitizer (PS) for photodynamic inactivation should have a pronounced antimicrobial efficacy but low dark toxicity. The aim of this study is to investigate the concentration-dependent antimicrobial efficacies of methylene blue (MB) and chlorin e6 (Ce6), against Streptococcus mutans biofilms and to compare the efficacies of these two PSs. The 48-h S. mutans UA159 biofilms, grown on glass coverslips, were subjected to MB or Ce6 at 25, 50, 100 and 200 μM with or without irradiation by 660 nM LED light (L). Control groups (-PS-L and -PS + L) were also included. Viability of the biofilm was analyzed by CFU/biofilm and biofilm lactic acid production was quantified by an enzymatic assay. With irradiation, MB under 25 μM resulted in 2-log reduction in biofilm viability and 30-fold reduction in biofilm lactic acid production. However, this biofilm killing efficacy did not change with increasing MB concentration. The biofilm killing efficacy of Ce6 increased with increasing Ce6 concentrations and resulted in 5-log reduction in biofilm viability. The lactic acid inhibitory effect of Ce6 was significantly lower than MB at 25 μM (p<0.01) but higher than MB at 200 μM (p=0.05), although the difference at 200 μM did not reach statistical significance. No dark toxicity could be observed for MB whereas low dark toxicity could be seen for Ce6 when the concentration is above 50 μM. Ce6 under 200 μM showed to be a more powerful PS for photodynamic inactivation than MB. Both Ce6- and MB-based photodynamic inactivation are useful methods for biofilm control in caries prevention.
Sections du résumé
BACKGROUND
BACKGROUND
An appropriate photosensitizer (PS) for photodynamic inactivation should have a pronounced antimicrobial efficacy but low dark toxicity. The aim of this study is to investigate the concentration-dependent antimicrobial efficacies of methylene blue (MB) and chlorin e6 (Ce6), against Streptococcus mutans biofilms and to compare the efficacies of these two PSs.
METHODS
METHODS
The 48-h S. mutans UA159 biofilms, grown on glass coverslips, were subjected to MB or Ce6 at 25, 50, 100 and 200 μM with or without irradiation by 660 nM LED light (L). Control groups (-PS-L and -PS + L) were also included. Viability of the biofilm was analyzed by CFU/biofilm and biofilm lactic acid production was quantified by an enzymatic assay.
RESULTS
RESULTS
With irradiation, MB under 25 μM resulted in 2-log reduction in biofilm viability and 30-fold reduction in biofilm lactic acid production. However, this biofilm killing efficacy did not change with increasing MB concentration. The biofilm killing efficacy of Ce6 increased with increasing Ce6 concentrations and resulted in 5-log reduction in biofilm viability. The lactic acid inhibitory effect of Ce6 was significantly lower than MB at 25 μM (p<0.01) but higher than MB at 200 μM (p=0.05), although the difference at 200 μM did not reach statistical significance. No dark toxicity could be observed for MB whereas low dark toxicity could be seen for Ce6 when the concentration is above 50 μM.
CONCLUSION
CONCLUSIONS
Ce6 under 200 μM showed to be a more powerful PS for photodynamic inactivation than MB. Both Ce6- and MB-based photodynamic inactivation are useful methods for biofilm control in caries prevention.
Identifiants
pubmed: 32407890
pii: S1572-1000(20)30171-X
doi: 10.1016/j.pdpdt.2020.101817
pii:
doi:
Substances chimiques
Chlorophyllides
0
Photosensitizing Agents
0
Porphyrins
0
phytochlorin
5S2CCF3T1Z
Methylene Blue
T42P99266K
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
101817Informations de copyright
Copyright © 2020 Elsevier B.V. All rights reserved.