Insights into the mechanisms of the antimicrobial photodynamic action toward biofilms using phenalen-1-one derivatives as photosensitizers

URN to cite this document:: urn:nbn:de:bvb:355-epub-439805
DOI to cite this document:: 10.5283/epub.43980

Muehler, Denise ; Rupp, Christina ; Keceli, Sercan ; Brochhausen, Christoph

; Siegmund, Heiko ; Maisch, Tim ; Hiller, Karl-Anton

; Buchalla, Wolfgang ; Cieplik, Fabian

Preview

License: Creative Commons Attribution 4.0
PDF - Published Version
(3MB)

Date of publication of this fulltext: 02 Nov 2020 11:55

Alternative links to fulltext:DOI Publisher

Details

Preview

Indexed in

Export bibliographical data

Abstract

Abstract

Introduction: In view of increasing resistance against antibiotics and antiseptics, antimicrobial photodynamic therapy (aPDT) may be a promising approach for use in dentistry. The aim of this study was to investigate the mechanism of action of aPDT with the phenalene-1-one derivatives SAPYR and SA-PN-05 as photosensitizers by evaluating bacterial ability to replicate, membrane integrity, metabolic activity, and formation of reactive oxygen species (ROS) in biofilms of Actinomyces naeslundii, Streptococcus mutans, and Escherichia coli. Materials and Methods: Single-species biofilms (A. naeslundii, S. mutans, and E. coli) were cultured under aerobic conditions for 48 h followed by treatment with the photosensitizers SAPYR and SA-PN-05 at various concentrations (0, 50, 100, 500 mM) and different incubation periods of 5, 10, 20, and 30 min and subsequent irradiation for 10 min (Waldmann PIB 3000; lambda(em) = 360-600 nm; 50 mW/cm(2); 30 J/cm(2)). Control samples were treated with dH(2)O and kept in dark for the same periods. Bacterial ability to replicate was evaluated by colony forming unit (CFU) assay. The cytoplasmic membrane integrity was investigated by flow cytometry using SYBR Green and propidium iodide and visualized by scanning and transmission electron microscopy. For SAPYR, metabolic activity and formation of intracellular ROS after irradiation were evaluated via luminescence and fluorometric assays, respectively. Results: SAPYR showed antimicrobial effects (>3 log(10) CFU reduction) on S. mutans after 5 min and on A. naeslundii after 20 min incubation and light activation. For E. coli, CFU reduction was >2 log(10) after 30 min of incubation. SA-PN-05 showed an antimicrobial effect after 5 min for all bacteria. Membrane damage upon aPDT with SAPYR was observed for E. coli, but not for S. mutans and A. naeslundii. Following treatment with SA-PN-05, irradiated samples and dark controls of all three species showed loss of membrane integrity. Luminescence and fluorometric assays showed a reduction in metabolic activity and an increase in formation of intracellular ROS in all three species upon aPDT treatment with SAPYR. Conclusion: The observed loss in ability to replicate upon aPDT with SAPYR in single-species biofilms may be due to an increase in formation of intracellular ROS upon photodynamic treatment.

Owner only: item control page

Download Statistics

Altmetric

Alternative Statistics (altmetrics)

More literature (via CORE)

Details

Preview

Indexed in

Export bibliographical data

Abstract

Abstract

Download Statistics

Downloads

Alternative Statistics (altmetrics)

More literature (via CORE)

University Library