ArticleFree radical biology & medicine2012
Paradoxical potentiation of methylene blue-mediated antimicrobial photodynamic inactivation by sodium azide: role of ambient oxygen and azide radicals.
Article in Free radical biology & medicine, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 55 papers.
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Who cites it
55 citing papers in PubMed, 120 citations in OpenAlex.
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- Mimicking a Light-Harvesting Complex to Accelerate Photooxidation in Asymmetric Lipid Membrane Nanoreactors.Angewandte Chemie (International ed. in English) · 2026Article
- Advanced Chlorine Photolysis for Carbamazepine Degradation: Tuning Radicals for Dissolved Organics.ACS ES&T water · 2026Article
- Manganese Porphyrin-Catalyzed One-Pot Oxidation of Lupeol: Efficient Conversion of Its Terminal Alkene Into Carboxylic Acids.Chemistry & biodiversity · 2026Article
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- Catalytic Degradation of Lignin over Sulfonyl-Chloride-Modified Lignin-Based Porous Carbon-Supported Metal Phthalocyanine: Effect of Catalyst Concentrations.Molecules (Basel, Switzerland) · 2024Article
- Oxygen Availability on the Application of Antimicrobial Photodynamic Therapy against Multi-Species Biofilms.Pathogens (Basel, Switzerland) · 2023Article
- Antimicrobial photodynamic therapy against oral biofilm: influencing factors, mechanisms, and combined actions with other strategies.Frontiers in microbiology · 2023Review
- Catastrophic chromosome fragmentation probes the nucleoid structure and dynamics in Escherichia coli.Nucleic acids research · 2022Article
- Exploring inactivation of SARS-CoV-2, MERS-CoV, Ebola, Lassa, and Nipah viruses on N95 and KN95 respirator material using photoactivated methylene blue to enable reuse.American journal of infection control · 2022Article
- Methylene Blue-Mediated Antimicrobial Photodynamic Therapy Against Clinical Isolates of Extensively Drug Resistant Gram-Negative Bacteria Causing Nosocomial Infections in Thailand, AnFrontiers in cellular and infection microbiology · 2022Article
- In Vivo Potentiation of Antimicrobial Photodynamic Therapy in a Mouse Model of Fungal Infection by Addition of Potassium Iodide.Methods in molecular biology (Clifton, N.J.) · 2022Article
- In Vitro Potentiation of Antimicrobial Photodynamic Inactivation by Addition of Potassium Iodide.Methods in molecular biology (Clifton, N.J.) · 2022Article
- Antimicrobial Photodynamic Therapy: Latest Developments with a Focus on Combinatory Strategies.Pharmaceutics · 2021Review
- Antimicrobial Photodynamic Approach in the Inactivation of Viruses in Wastewater: Influence of Alternative Adjuvants.Antibiotics (Basel, Switzerland) · 2021Article
- Interplay of phosphate and carbonate ions with flavin photosensitizers in photodynamic inactivation of bacteria.PloS one · 2021Article
- Photoreactivity of Bis-retinoid A2E Complexed with a Model Protein in Selected Model Systems.Cell biochemistry and biophysics · 2020Article
- Antimicrobial Photoinactivation Approach Based on Natural Agents for Control of Bacteria Biofilms in Spacecraft.International journal of molecular sciences · 2020Review
- Comparative Study Regarding the Properties of Methylene Blue and Proflavine and Their Optimal Concentrations for In Vitro and In Vivo Applications.Diagnostics (Basel, Switzerland) · 2020Review
- Oxygen-Independent Antimicrobial Photoinactivation: Type III Photochemical Mechanism?Antibiotics (Basel, Switzerland) · 2020Review
Corrections and comments
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Authors and funding
8 authors at 6 institutions in 4 countries.
Funding
Abstract
Sodium azide (NaN(3)) is widely employed to quench singlet oxygen during photodynamic therapy (PDT), especially when PDT is used to kill bacteria in suspension. We observed that addition of NaN(3) (100 μM or 10 mM) to gram-positive Staphylococcus aureus and gram-negative Escherichia coli incubated with methylene blue (MB) and illuminated with red light gave significantly increased bacterial killing (1-3 logs), rather than the expected protection from killing. A different antibacterial photosensitizer, the conjugate between polyethylenimine and chlorin(e6) (PEI-ce6), showed reduced PDT killing (1-2 logs) after addition of 10mM NaN(3). Azide (0.5mM) potentiated bacterial killing by Fenton reagent (hydrogen peroxide and ferrous sulfate) by up to 3 logs, but protected against killing mediated by sodium hypochlorite and hydrogen peroxide (considered to be a chemical source of singlet oxygen). The intermediacy of N(3)() was confirmed by spin-trapping and electron spin resonance studies in both MB-photosensitized reactions and Fenton reagent with addition of NaN(3). We found that N(3)() was formed and bacteria were killed even in the absence of oxygen, suggesting the direct one-electron oxidation of azide anion by photoexcited MB. This observation suggests a possible mechanism to carry out oxygen-independent PDT.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.