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Carboranyl-Chlorin e6 as a Potent Antimicrobial Photosensitizer.

Omarova EO, Nazarov PA, Firsov AM, Strakhovskaya MG, Arkhipova AY, Moisenovich MM, Agapov II, Ol'shevskaya VA, Zaitsev AV, Kalinin VN, Kotova EA, Antonenko YN - PLoS ONE (2015)

Bottom Line: Antimicrobial photodynamic inactivation is currently being widely considered as alternative to antibiotic chemotherapy of infective diseases, attracting much attention to design of novel effective photosensitizers.Carboranyl-chlorin-e6 (the conjugate of chlorin e6 with carborane), applied here for the first time for antimicrobial photodynamic inactivation, appeared to be much stronger than chlorin e6 against Gram-positive bacteria, such as Bacillus subtilis, Staphyllococcus aureus and Mycobacterium sp.Unlike chlorin e6, the conjugate showed higher (compared to the wild-type strain) dark toxicity with Escherichia coli ΔtolC mutant, deficient in TolC-requiring multidrug efflux transporters.

View Article: PubMed Central - PubMed

Affiliation: Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.

ABSTRACT
Antimicrobial photodynamic inactivation is currently being widely considered as alternative to antibiotic chemotherapy of infective diseases, attracting much attention to design of novel effective photosensitizers. Carboranyl-chlorin-e6 (the conjugate of chlorin e6 with carborane), applied here for the first time for antimicrobial photodynamic inactivation, appeared to be much stronger than chlorin e6 against Gram-positive bacteria, such as Bacillus subtilis, Staphyllococcus aureus and Mycobacterium sp. Confocal fluorescence spectroscopy and membrane leakage experiments indicated that bacteria cell death upon photodynamic treatment with carboranyl-chlorin-e6 is caused by loss of cell membrane integrity. The enhanced photobactericidal activity was attributed to the increased accumulation of the conjugate by bacterial cells, as evaluated both by centrifugation and fluorescence correlation spectroscopy. Gram-negative bacteria were rather resistant to antimicrobial photodynamic inactivation mediated by carboranyl-chlorin-e6. Unlike chlorin e6, the conjugate showed higher (compared to the wild-type strain) dark toxicity with Escherichia coli ΔtolC mutant, deficient in TolC-requiring multidrug efflux transporters.

No MeSH data available.


Related in: MedlinePlus

A. Membrane integrity of BACE- and chlorin e6-treated B. subtilis cells after illumination. Photosensitizers are depicted in blue color, propidium iodide (PI)–in red color. Membrane integrity was assessed by counting PI-positive cells after illumination with red light at 4 J/cm2. B. Intracellular localization of the photosensitizers measured by confocal laser microscopy.
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pone.0141990.g004: A. Membrane integrity of BACE- and chlorin e6-treated B. subtilis cells after illumination. Photosensitizers are depicted in blue color, propidium iodide (PI)–in red color. Membrane integrity was assessed by counting PI-positive cells after illumination with red light at 4 J/cm2. B. Intracellular localization of the photosensitizers measured by confocal laser microscopy.

Mentions: By applying CLSM to B. subtilis cells incubated with PI, we compared the light-induced effects on cell membrane integrity in the presence of BACE and chlorin e6. As seen from Fig 4A, the percentage of cells permeable to PI was much higher after the photodynamic treatment with BACE, than with chlorin e6, thereby indicating the involvement of membrane damage in the PDI of bacterial cells. This assumption was supported by CLSM images of BACE and chlorin e6 distribution in cells of B. subtilis, which revealed predominant localization of BACE on the surface of bacterial cells (Fig 4B). With E. coli the changes in PI permeability were negligible under these conditions (data not shown).


Carboranyl-Chlorin e6 as a Potent Antimicrobial Photosensitizer.

Omarova EO, Nazarov PA, Firsov AM, Strakhovskaya MG, Arkhipova AY, Moisenovich MM, Agapov II, Ol'shevskaya VA, Zaitsev AV, Kalinin VN, Kotova EA, Antonenko YN - PLoS ONE (2015)

A. Membrane integrity of BACE- and chlorin e6-treated B. subtilis cells after illumination. Photosensitizers are depicted in blue color, propidium iodide (PI)–in red color. Membrane integrity was assessed by counting PI-positive cells after illumination with red light at 4 J/cm2. B. Intracellular localization of the photosensitizers measured by confocal laser microscopy.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4633095&req=5

pone.0141990.g004: A. Membrane integrity of BACE- and chlorin e6-treated B. subtilis cells after illumination. Photosensitizers are depicted in blue color, propidium iodide (PI)–in red color. Membrane integrity was assessed by counting PI-positive cells after illumination with red light at 4 J/cm2. B. Intracellular localization of the photosensitizers measured by confocal laser microscopy.
Mentions: By applying CLSM to B. subtilis cells incubated with PI, we compared the light-induced effects on cell membrane integrity in the presence of BACE and chlorin e6. As seen from Fig 4A, the percentage of cells permeable to PI was much higher after the photodynamic treatment with BACE, than with chlorin e6, thereby indicating the involvement of membrane damage in the PDI of bacterial cells. This assumption was supported by CLSM images of BACE and chlorin e6 distribution in cells of B. subtilis, which revealed predominant localization of BACE on the surface of bacterial cells (Fig 4B). With E. coli the changes in PI permeability were negligible under these conditions (data not shown).

Bottom Line: Antimicrobial photodynamic inactivation is currently being widely considered as alternative to antibiotic chemotherapy of infective diseases, attracting much attention to design of novel effective photosensitizers.Carboranyl-chlorin-e6 (the conjugate of chlorin e6 with carborane), applied here for the first time for antimicrobial photodynamic inactivation, appeared to be much stronger than chlorin e6 against Gram-positive bacteria, such as Bacillus subtilis, Staphyllococcus aureus and Mycobacterium sp.Unlike chlorin e6, the conjugate showed higher (compared to the wild-type strain) dark toxicity with Escherichia coli ΔtolC mutant, deficient in TolC-requiring multidrug efflux transporters.

View Article: PubMed Central - PubMed

Affiliation: Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.

ABSTRACT
Antimicrobial photodynamic inactivation is currently being widely considered as alternative to antibiotic chemotherapy of infective diseases, attracting much attention to design of novel effective photosensitizers. Carboranyl-chlorin-e6 (the conjugate of chlorin e6 with carborane), applied here for the first time for antimicrobial photodynamic inactivation, appeared to be much stronger than chlorin e6 against Gram-positive bacteria, such as Bacillus subtilis, Staphyllococcus aureus and Mycobacterium sp. Confocal fluorescence spectroscopy and membrane leakage experiments indicated that bacteria cell death upon photodynamic treatment with carboranyl-chlorin-e6 is caused by loss of cell membrane integrity. The enhanced photobactericidal activity was attributed to the increased accumulation of the conjugate by bacterial cells, as evaluated both by centrifugation and fluorescence correlation spectroscopy. Gram-negative bacteria were rather resistant to antimicrobial photodynamic inactivation mediated by carboranyl-chlorin-e6. Unlike chlorin e6, the conjugate showed higher (compared to the wild-type strain) dark toxicity with Escherichia coli ΔtolC mutant, deficient in TolC-requiring multidrug efflux transporters.

No MeSH data available.


Related in: MedlinePlus