Antimicrobial photodynamic effect of phenothiazinic photosensitizers in formulations with ethanol on Pseudomonas aeruginosa biofilms
| Autor: | Maritieli Righi Martins, Roberto Christ Vianna Santos, Emilia Pithan Prochnow, Marcos A. Villetti, Karla Zanini Kantorski, Cibele Bruno Campagnolo |
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| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
Cell Survival Drug Compounding 030106 microbiology Biophysics Dermatology medicine.disease_cause Microbiology 03 medical and health sciences Acetic acid chemistry.chemical_compound Phenothiazines medicine Pharmacology (medical) Toluidine Ethanol Photosensitizing Agents Singlet Oxygen Chemistry Pseudomonas aeruginosa Singlet oxygen Sterilization Antimicrobial Oncology Photochemotherapy Biofilms Sodium acetate Methylene blue Nuclear chemistry |
| Zdroj: | Photodiagnosis and photodynamic therapy. 13 |
| ISSN: | 1873-1597 |
| Popis: | Background data Methylene blue (MB) and toluidine blue (TB) are recognized as safe photosensitizers (Ps) for use in humans. The clinical effectiveness of the antimicrobial photodynamic therapy with MB and TB needs to be optimized, and ethanol can increase their antimicrobial effect. Formulations of MB and TB containing ethanol were evaluated for their ability to produce singlet oxygen and their antibacterial effect on Pseudomonas aeruginosa biofilms. Methods Photoactivated formulations were prepared by diluting the Ps (250 μM) in buffered water (pH 5.6, sodium acetate/acetic acid), 10% ethanol (buffer: ethanol, 90:10), or 20% ethanol (buffer: ethanol, 80:20). Biofilms also were exposed to the buffer, 10% ethanol, or 20% ethanol without photoactivation. Untreated biofilm was considered the control group. The production of singlet oxygen in the formulations was measured based on the photo-oxidation of 1,3-diphenylisobenzofuran. The photo-oxidation and CFU (log 10 ) data were evaluated by two-way ANOVA and post-hoc Tukey’s tests. Results In all the formulations, compared to TB, MB showed higher production of singlet oxygen. In the absence of photoactivation, neither the buffer nor the 10% ethanol solution showed any antimicrobial effect, while the 20% ethanol solution significantly reduced bacterial viability ( P = 0.009). With photoactivation, only the formulations containing MB and both 10% and 20% ethanol solutions significantly reduced the viability of P. aeruginosa biofilms when compared with the control. Conclusions MB formulations containing ethanol enhanced the antimicrobial effect of the photodynamic therapy against P. aeruginosa biofilms in vitro. |
| Databáze: | OpenAIRE |
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