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Cieplik F, Wimmer F, Muehler D, Thurnheer T, Belibasakis G, Hiller KA, Maisch T, Buchalla W. Phenalen-1-One-Mediated Antimicrobial Photodynamic Therapy and Chlorhexidine Applied to a Novel Caries Biofilm Model. Caries Res 2018; 52:447-453. [DOI: 10.1159/000487815] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/14/2018] [Indexed: 11/19/2022] Open
Abstract
Antimicrobial photodynamic therapy (aPDT) may be useful as a supportive antimicrobial measure for caries-active subjects. In this study, the antimicrobial efficacy of aPDT with a phenalen-1-one photosensitizer was evaluated in a novel in vitro biofilm model comprising Actinomyces naeslundii, Actinomyces odontolyticus, and Streptococcus mutans and was compared to chlorhexidine. The proposed biofilm model allows high-throughput screening for antimicrobial efficacy while exhibiting a differentiated response to different antimicrobial approaches. While chlorhexidine 0.2% showed a reduction of ≈4 log10 for all species, aPDT led to a more pronounced reduction of S. mutans (2.8 log10) than of Actinomyces spp. (1.2 or 1.3 log10). A similar effect was also observed in monospecies biofilms. Therefore, aPDT may be more effective against S. mutans than against Actinomyces spp. when in biofilms, and this antimicrobial approach merits further investigations.
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Muehler D, Sommer K, Wennige S, Hiller KA, Cieplik F, Maisch T, Späth A. Light-activated phenalen-1-one bactericides: efficacy, toxicity and mechanism compared with benzalkonium chloride. Future Microbiol 2017; 12:1297-1310. [DOI: 10.2217/fmb-2016-0229] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Aim: Five photoactive compounds with variable elongated alkyl-substituents in a phenalen-1-one structure were examined in view of structural similarity to the antimicrobial agent benzalkonium chloride (BAC). Methods: All phenalen-1-ones and BAC were evaluated for their antimicrobial properties against Staphylococcus aureus, methicillin-resistant S. aureus, Escherichia coli, Pseudomonas aeruginosa and for their eukaryotic toxicity against normal human epidermal keratinocyte (NHEK) cells to narrow down the BAC-like effect and the photodynamic effect depending on the chemical structure. All compounds were investigated for effective concentration ranges, where a bacterial reduction of 5 log10 is achieved, while an NHEK survival of 80% is ensured. Results: Effective concentration ranges were found for four out of five photoactive compounds, but not for BAC and the compound with BAC-like alkyl chain length. Conclusion: Chain length size and polar area of the respective head-groups of phenalen-1-one compounds or BAC showed an influence on the incorporation inside lipid membranes and thus, head-groups may have an impact on the toxicity of antimicrobials.
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Affiliation(s)
- Denise Muehler
- Department of Conservative Dentistry & Periodontology, University Medical Center Regensburg, Regensburg, Germany
| | - Kerstin Sommer
- Department of Conservative Dentistry & Periodontology, University Medical Center Regensburg, Regensburg, Germany
| | - Sara Wennige
- Department of Conservative Dentistry & Periodontology, University Medical Center Regensburg, Regensburg, Germany
- Department of Dermatology, University Medical Center Regensburg, Regensburg, Germany
| | - Karl-Anton Hiller
- Department of Conservative Dentistry & Periodontology, University Medical Center Regensburg, Regensburg, Germany
| | - Fabian Cieplik
- Department of Conservative Dentistry & Periodontology, University Medical Center Regensburg, Regensburg, Germany
| | - Tim Maisch
- Department of Dermatology, University Medical Center Regensburg, Regensburg, Germany
| | - Andreas Späth
- Department of Organic Chemistry, University of Regensburg, Regensburg, Germany
- TriOptoTec GmbH, Regensburg, Germany
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Eckl DB, Dengler L, Nemmert M, Eichner A, Bäumler W, Huber H. A Closer Look at Dark Toxicity of the Photosensitizer TMPyP in Bacteria. Photochem Photobiol 2017; 94:165-172. [PMID: 28940456 DOI: 10.1111/php.12846] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 09/10/2017] [Indexed: 12/24/2022]
Abstract
Photodynamic inactivation of bacteria (PIB) is based on photosensitizers which absorb light and generate reactive oxygen species (ROS), killing cells via oxidation. PIB is evaluated by comparing viability with and without irradiation, where reduction of viability in the presence of the photosensitizer without irradiation is considered as dark toxicity. This effect is controversially discussed for photosensitizers like TMPyP (5,10,15,20-Tetrakis(1-methyl-4-pyridinio)porphyrin tetra(p-toluensulfonate). TMPyP shows a high absorption coefficient for blue light and a high yield of ROS production, especially singlet oxygen. Escherichia coli and Bacillus atrophaeus were incubated with TMPyP and irradiated with different light sources at low radiant exposures (μW per cm²), reflecting laboratory conditions of dark toxicity evaluation. Inactivation of E. coli occurs for blue light, while no effect was detectable for wavelengths >450 nm. Being more susceptible toward PIB, growth of B. atrophaeus is even reduced for light with emission >450 nm. Decreasing the light intensities to nW per cm² for B. atrophaeus, application of TMPyP still caused bacterial killing. Toxic effects of TMPyP disappeared after addition of histidine, quenching residual ROS. Our experiments demonstrate that the evaluation of dark toxicity of a powerful photosensitizer like TMPyP requires low light intensities and if necessary additional application of substances quenching any residual ROS.
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Affiliation(s)
- Daniel B Eckl
- Institute for Microbiology and Archaea Center, University of Regensburg, Regensburg, Germany
| | - Linda Dengler
- Institute for Microbiology and Archaea Center, University of Regensburg, Regensburg, Germany
| | - Marina Nemmert
- Institute for Microbiology and Archaea Center, University of Regensburg, Regensburg, Germany
| | - Anja Eichner
- Department of Dermatology, University hospital Regensburg, Regensburg, Germany
| | - Wolfgang Bäumler
- Department of Dermatology, University hospital Regensburg, Regensburg, Germany
| | - Harald Huber
- Institute for Microbiology and Archaea Center, University of Regensburg, Regensburg, Germany
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Antimicrobial efficacy of irradiation with visible light on oral bacteria in vitro: a systematic review. Future Med Chem 2017; 9:1557-1574. [PMID: 28792235 DOI: 10.4155/fmc-2017-0051] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
AIM Resistances to antibiotics employed for treatment of infectious diseases have increased to alarming numbers making it more and more difficult to treat diseases caused by microorganisms resistant to common antibiotics. Consequently, novel methods for successful inactivation of pathogens are required. In this instance, one alternative could be application of light for treatment of topical infections. Antimicrobial properties of UV light are well documented, but due to its DNA-damaging properties use for medical purposes is limited. In contrast, irradiation with visible light may be more promising. METHODS Literature was systematically screened for research concerning inactivation of main oral bacterial species by means of visible light. RESULTS Inactivation of bacterial species, especially pigmented ones, in planktonic state showed promising results. There is a lack of research examining the situation when organized as biofilms. CONCLUSION More research concerning situation in a biofilm state is required.
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Cieplik F, Buchalla W, Hellwig E, Al-Ahmad A, Hiller KA, Maisch T, Karygianni L. Antimicrobial photodynamic therapy as an adjunct for treatment of deep carious lesions—A systematic review. Photodiagnosis Photodyn Ther 2017; 18:54-62. [DOI: 10.1016/j.pdpdt.2017.01.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 12/29/2016] [Accepted: 01/13/2017] [Indexed: 11/15/2022]
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Schmalz G, Galler KM. Biocompatibility of biomaterials – Lessons learned and considerations for the design of novel materials. Dent Mater 2017; 33:382-393. [DOI: 10.1016/j.dental.2017.01.011] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 01/31/2017] [Indexed: 12/14/2022]
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Xue D, Zhao Y. Clinical effectiveness of adjunctive antimicrobial photodynamic therapy for residual pockets during supportive periodontal therapy: A systematic review and meta-analysis. Photodiagnosis Photodyn Ther 2017; 17:127-133. [DOI: 10.1016/j.pdpdt.2016.11.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 10/21/2016] [Accepted: 11/19/2016] [Indexed: 11/27/2022]
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Gollmer A, Felgentraeger A, Maisch T, Flors C. Real-time imaging of photodynamic action in bacteria. JOURNAL OF BIOPHOTONICS 2017; 10:264-270. [PMID: 26790971 DOI: 10.1002/jbio.201500259] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 01/04/2016] [Accepted: 01/05/2016] [Indexed: 06/05/2023]
Abstract
Fluorescence imaging studies of the processes leading to photodynamic inactivation of bacteria have been limited due to the small size of microorganisms as well as by the faint fluorescence of most photosensitizers. A versatile method based on highly-sensitive fluorescence microscopy is presented which allows to study, in real time, the incorporation of photosensitizers inside S. aureus upon photodynamic action. The method takes advantage of the fluorescence enhancement of phenothiazine and porphyrin photosensitizers upon entering the bacterial cytosol after the cell wall has been compromised. In combination with typical assays, such as the addition of specific enhancers of reactive oxygen species, it is possible to extract mechanistic information about the pathway of photodynamic damage at the single-cell level. Imaging experiments in deuterated buffer strongly support a Type-I mechanism for methylene blue and a very minor role of singlet oxygen.
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Affiliation(s)
- Anita Gollmer
- Department of Dermatology, University Hospital Regensburg, 93053, Regensburg, Germany
| | - Ariane Felgentraeger
- Department of Dermatology, University Hospital Regensburg, 93053, Regensburg, Germany
| | - Tim Maisch
- Department of Dermatology, University Hospital Regensburg, 93053, Regensburg, Germany
| | - Cristina Flors
- Madrid Institute for Advanced Studies in Nanoscience (IMDEA Nanociencia) and Nanobiotechnology Unit Associated to the National Center for Biotechnology (CSIC), 28049, Madrid, Spain
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Tavares LJ, Pavarina AC, Vergani CE, de Avila ED. The impact of antimicrobial photodynamic therapy on peri-implant disease: What mechanisms are involved in this novel treatment? Photodiagnosis Photodyn Ther 2016; 17:236-244. [PMID: 27939958 DOI: 10.1016/j.pdpdt.2016.11.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/27/2016] [Accepted: 11/29/2016] [Indexed: 10/20/2022]
Abstract
According to the American Academy of Implant Dentistry, 3 million Americans have dental implants, and this number is growing by 500,000 each year. Proportionally, the number of biological complications is also increasing. Among them, peri-implant disease is considered the most common cause of implant loss after osseointegration. In this context, microorganisms residing on the surfaces of implants and their prosthetic components are considered to be the primary etiologic factor for peri-implantitis. Some research groups have proposed combining surgical and non-surgical therapies with systemic antibiotics. The major problem associated with the use of antibiotics to treat peri-implantitis is that microorganisms replicate very quickly. Moreover, inappropriate prescription of antibiotics is not only associated with potential resistance but also and most importantly with the development of superinfections that are difficult to eradicate. Although antimicrobial photodynamic therapy (aPDT) was discovered several years ago, aPDT has only recently emerged as a possible alternative therapy against different oral pathogens causing peri-implantitis. The mechanism of action of aPDT is based on a combination of a photosensitizer drug and light of a specific wavelength in the presence of oxygen. The reaction between light and oxygen produces toxic forms of oxygen species that can kill microbial cells. This mechanism is crucial to the efficacy of aPDT. To help us understand conflicting data, it is necessary to know all the particularities of the etiology of peri-implantitis and the aPDT compounds. We believe that this review will draw attention to new insights regarding the impact of aPDT on peri-implant disease.
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Affiliation(s)
- Lívia Jacovassi Tavares
- Department of Dental Materials and Prosthodontics, School of Dentistry at Araraquara, Univ Estadual Paulista-UNESP, Rua Humaitá, 1680, 14801-903 Araraquara, SP, Brazil
| | - Ana Claudia Pavarina
- Department of Dental Materials and Prosthodontics, School of Dentistry at Araraquara, Univ Estadual Paulista-UNESP, Rua Humaitá, 1680, 14801-903 Araraquara, SP, Brazil
| | - Carlos Eduardo Vergani
- Department of Dental Materials and Prosthodontics, School of Dentistry at Araraquara, Univ Estadual Paulista-UNESP, Rua Humaitá, 1680, 14801-903 Araraquara, SP, Brazil
| | - Erica Dorigatti de Avila
- Department of Dental Materials and Prosthodontics, School of Dentistry at Araraquara, Univ Estadual Paulista-UNESP, Rua Humaitá, 1680, 14801-903 Araraquara, SP, Brazil.
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Wainwright M, Maisch T, Nonell S, Plaetzer K, Almeida A, Tegos GP, Hamblin MR. Photoantimicrobials-are we afraid of the light? THE LANCET. INFECTIOUS DISEASES 2016; 17:e49-e55. [PMID: 27884621 PMCID: PMC5280084 DOI: 10.1016/s1473-3099(16)30268-7] [Citation(s) in RCA: 419] [Impact Index Per Article: 52.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 06/28/2016] [Accepted: 07/14/2016] [Indexed: 02/07/2023]
Abstract
Although conventional antimicrobial drugs have been viewed as miraculous cure-alls for the past 80 years, increasing antimicrobial drug resistance requires a major and rapid intervention. However, the development of novel but still conventional systemic antimicrobial agents, having only a single mode or site of action, will not alleviate the situation because it is probably only a matter of time until any such agents will also become ineffective. To continue to produce new agents based on this notion is unacceptable, and there is an increasing need for alternative approaches to the problem. By contrast, light-activated molecules called photoantimicrobials act locally via the in-situ production of highly reactive oxygen species, which simultaneously attack various biomolecular sites in the pathogenic target and therefore offer both multiple and variable sites of action. This non-specificity at the target circumvents conventional mechanisms of resistance and inhibits the development of resistance to the agents themselves. Photoantimicrobial therapy is safe and easy to implement and, unlike conventional agents, the activity spectrum of photoantimicrobials covers bacteria, fungi, viruses, and protozoa. However, clinical trials of these new, truly broad-spectrum, and minimally toxic agents have been few, and the funding for research and development is almost non-existent. Photoantimicrobials constitute one of the few ways forward through the morass of drug-resistant infectious disease and should be fully explored. In this Personal View, we raise awareness of the novel photoantimicrobial technologies that offer a viable alternative to conventional drugs in many relevant application fields, and could thus slow the pace of resistance development.
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Affiliation(s)
- Mark Wainwright
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK.
| | - Tim Maisch
- Department of Dermatology, University Medical Center Regensburg, Regensburg, Germany
| | - Santi Nonell
- Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona, Spain
| | - Kristjan Plaetzer
- Laboratory of Photodynamic Inactivation of Microorganisms, Department of Materials Science and Physics, University of Salzburg, Salzburg, Austria
| | - Adelaide Almeida
- Department of Biology, and Centre for Environmental and Marine (CESAM) Studies, University of Aveiro, Aveiro, Portugal
| | - George P Tegos
- The Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA; Department of Dermatology, Harvard Medical School, Boston, MA, USA
| | - Michael R Hamblin
- The Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA; Department of Dermatology, Harvard Medical School, Boston, MA, USA; Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
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Effect of fiber insertion depth on antibacterial efficacy of photodynamic therapy against Enterococcus faecalis in rootcanals. Clin Oral Investig 2016; 21:1753-1759. [PMID: 27591860 DOI: 10.1007/s00784-016-1948-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 08/30/2016] [Indexed: 10/21/2022]
Abstract
OBJECTIVES This in vitro study evaluated the effect of fiber insertion depth on antimicrobial efficacy of antimicrobial photodynamic therapy (aPDT) using a photosensitizer (PS; toluidine blue) and a red light-emitting diode (LED) in root canals infected with Enterococcus faecalis. MATERIALS AND METHODS Single-rooted extracted teeth were prepared with nickel-titanium-instruments, sterilized, contaminated with E. faecalis, and incubated for 72 h. Roots were randomly divided into four experimental groups: PS only, LED only, aPDT with LED in the apical third, aPDT with LED in the coronal third, as well as into infection and sterile controls (each n = 10). Samples were taken by collecting standardized dentine shavings from the root canal walls. After serial dilution and culturing on blood agar, colony-forming units (CFU) were counted. RESULTS Both aPDT groups showed a CFU reduction of 1-2 log10 steps compared with the infection control, whereas the effect of fiber insertion depth was negligible (<0.5 log10 steps). CFU reduction of approximately 0.5 log10 steps for PS alone was detected compared with the infection control, but PS alone was less effective than both aPDT groups. No antibacterial effect was detected for LED alone. CONCLUSIONS aPDT reduced E. faecalis within the root canal, whereas fiber insertion depth had a negligible influence on antimicrobial effectiveness of aPDT. CLINICAL RELEVANCE The insertion depth of the light-emitting diode may not influence the antibacterial efficacy of photodynamic therapy against E. faecalis in straight root canals.
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Ghanem A, Pasumarthy S, Ranna V, Kellesarian SV, Abduljabbar T, Vohra F, Malmstrom H. Is mechanical curettage with adjunct photodynamic therapy more effective in the treatment of peri-implantitis than mechanical curettage alone? Photodiagnosis Photodyn Ther 2016; 15:191-6. [DOI: 10.1016/j.pdpdt.2016.06.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 06/15/2016] [Accepted: 06/22/2016] [Indexed: 12/12/2022]
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Kossakowska-Zwierucho M, Kaźmierkiewicz R, Bielawski KP, Nakonieczna J. Factors Determining Staphylococcus aureus Susceptibility to Photoantimicrobial Chemotherapy: RsbU Activity, Staphyloxanthin Level, and Membrane Fluidity. Front Microbiol 2016; 7:1141. [PMID: 27486456 PMCID: PMC4949386 DOI: 10.3389/fmicb.2016.01141] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/07/2016] [Indexed: 12/22/2022] Open
Abstract
Photoantimicrobial chemotherapy (PACT) constitutes a particular type of stress condition, in which bacterial cells induce a pleiotropic and as yet unexplored effect. In light of this, the key master regulators are of putative significance to the overall phototoxic outcome. In Staphylococcus aureus, the alternative sigma factor σB controls the expression of genes involved in the response to environmental stress. We show that aberration of any sigB operon genes in S. aureus USA300 isogenic mutants causes a pronounced sensitization (>5 log10 reduction in CFU drop) to PACT with selected photosensitizers, namely protoporphyrin diarginate, zinc phthalocyanine and rose bengal. This effect is partly due to aberration-coupled staphyloxanthin synthesis inhibition. We identified frequent mutations in RsbU, a σB activator, in PACT-vulnerable clinical isolates of S. aureus, resulting in σB activity impairment. Locations of significant changes in protein structure (IS256 insertion, early STOP codon occurrence, substitutions A230T and A276D) were shown in a theoretical model of S. aureus RsbU. As a phenotypic hallmark of PACT-vulnerable S. aureus strains, we observed an increased fluidity of bacterial cell membrane, which is a result of staphyloxanthin content and other yet unidentified factors. Our research indicates σB as a promising target of adjunctive antimicrobial therapy and suggests that enhanced cell membrane fluidity may be an adjuvant strategy in PACT.
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Affiliation(s)
- Monika Kossakowska-Zwierucho
- Laboratory of Molecular Diagnostics, Department of Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk Gdansk, Poland
| | - Rajmund Kaźmierkiewicz
- Laboratory of Biomolecular Systems Simulation, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk Gdansk, Poland
| | - Krzysztof P Bielawski
- Laboratory of Molecular Diagnostics, Department of Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk Gdansk, Poland
| | - Joanna Nakonieczna
- Laboratory of Molecular Diagnostics, Department of Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk Gdansk, Poland
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Hamblin MR. Antimicrobial photodynamic inactivation: a bright new technique to kill resistant microbes. Curr Opin Microbiol 2016; 33:67-73. [PMID: 27421070 DOI: 10.1016/j.mib.2016.06.008] [Citation(s) in RCA: 455] [Impact Index Per Article: 56.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 06/10/2016] [Accepted: 06/27/2016] [Indexed: 01/13/2023]
Abstract
Photodynamic therapy (PDT) uses photosensitizers (non-toxic dyes) that are activated by absorption of visible light to form reactive oxygen species (including singlet oxygen) that can oxidize biomolecules and destroy cells. Antimicrobial photodynamic inactivation (aPDI) can treat localized infections. aPDI neither causes any resistance to develop in microbes, nor is affected by existing drug resistance status. We discuss some recent developments in aPDI. New photosensitizers including polycationic conjugates, stable synthetic bacteriochlorins and functionalized fullerenes are described. The microbial killing by aPDI can be synergistically potentiated (several logs) by harmless inorganic salts via photochemistry. Genetically engineered bioluminescent microbial cells allow PDT to treat infections in animal models. Photoantimicrobials have a promising future in the face of the unrelenting increase in antibiotic resistance.
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Affiliation(s)
- Michael R Hamblin
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA; Department of Dermatology, Harvard Medical School, Boston, MA, USA; Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA.
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Abstract
Photodynamic therapy (PDT) was discovered more than 100 years ago, and has since become a well-studied therapy for cancer and various non-malignant diseases including infections. PDT uses photosensitizers (PSs, non-toxic dyes) that are activated by absorption of visible light to initially form the excited singlet state, followed by transition to the long-lived excited triplet state. This triplet state can undergo photochemical reactions in the presence of oxygen to form reactive oxygen species (including singlet oxygen) that can destroy cancer cells, pathogenic microbes and unwanted tissue. The dual-specificity of PDT relies on accumulation of the PS in diseased tissue and also on localized light delivery. Tetrapyrrole structures such as porphyrins, chlorins, bacteriochlorins and phthalocyanines with appropriate functionalization have been widely investigated in PDT, and several compounds have received clinical approval. Other molecular structures including the synthetic dyes classes as phenothiazinium, squaraine and BODIPY (boron-dipyrromethene), transition metal complexes, and natural products such as hypericin, riboflavin and curcumin have been investigated. Targeted PDT uses PSs conjugated to antibodies, peptides, proteins and other ligands with specific cellular receptors. Nanotechnology has made a significant contribution to PDT, giving rise to approaches such as nanoparticle delivery, fullerene-based PSs, titania photocatalysis, and the use of upconverting nanoparticles to increase light penetration into tissue. Future directions include photochemical internalization, genetically encoded protein PSs, theranostics, two-photon absorption PDT, and sonodynamic therapy using ultrasound.
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Cieplik F, Pummer A, Leibl C, Regensburger J, Schmalz G, Buchalla W, Hiller KA, Maisch T. Photodynamic Inactivation of Root Canal Bacteria by Light Activation through Human Dental Hard and Simulated Surrounding Tissue. Front Microbiol 2016; 7:929. [PMID: 27379059 PMCID: PMC4908107 DOI: 10.3389/fmicb.2016.00929] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/31/2016] [Indexed: 11/16/2022] Open
Abstract
Introduction: Photodynamic inactivation of bacteria (PIB) may be a supportive antimicrobial approach for use in endodontics, but sufficient activation of photosensitizers (PS) in root canals is a critical point. Therefore, aim of this study was to evaluate the ability of PS absorbing blue (TMPyP) or red light (Methylene Blue; MB) for light activation through human dental hard and simulated surrounding tissue to inactivate root canal bacteria. Methods: A tooth model was fabricated with a human premolar and two molars in an acrylic resin bloc simulating the optical properties of a porcine jaw. The distal root canal of the first molar was enlarged to insert a glass tube (external diameter 2 mm) containing PS and stationary-phase Enterococcus faecalis. Both PS (10 μM) were irradiated for 120 s with BlueV (20 mW/cm2; λem = 400–460 nm) or PDT 1200L (37.8 mW/cm2; λem = 570–680 nm; both: Waldmann Medizintechnik), respectively. Irradiation parameters ensured identical numbers of photons absorbed by each PS. Three setups were chosen: irradiating the glass pipette only (G), the glass pipette inside the single tooth without (GT) and with (GTM) simulated surrounding tissues. Colony forming units (CFU) were evaluated. Transmission measurements of the buccal halves of hemisected mandibular first molars were performed by means of a photospectrometer. Results: PIB with both PS led to reduction by ≥ 5 log10 of E. faecalis CFU for each setup. From transmission measurements, a threshold wavelength λth for allowing an amount of light transmission for sufficient activation of PS was determined to be 430 nm. Conclusion: This study can be seen as proof of principle that light activation of given intra-canal PS from outside a tooth may be possible at wavelengths ≥ 430 nm, facilitating clinical application of PIB in endodontics.
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Affiliation(s)
- Fabian Cieplik
- Department of Conservative Dentistry and Periodontology, University Medical Center Regensburg Regensburg, Germany
| | - Andreas Pummer
- Department of Conservative Dentistry and Periodontology, University Medical Center Regensburg Regensburg, Germany
| | - Christoph Leibl
- Department of Conservative Dentistry and Periodontology, University Medical Center RegensburgRegensburg, Germany; Private PracticeGeiselhöring, Germany
| | | | - Gottfried Schmalz
- Department of Conservative Dentistry and Periodontology, University Medical Center RegensburgRegensburg, Germany; Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of BernBern, Switzerland
| | - Wolfgang Buchalla
- Department of Conservative Dentistry and Periodontology, University Medical Center Regensburg Regensburg, Germany
| | - Karl-Anton Hiller
- Department of Conservative Dentistry and Periodontology, University Medical Center Regensburg Regensburg, Germany
| | - Tim Maisch
- Department of Dermatology, University Medical Center Regensburg Regensburg, Germany
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Mamone L, Ferreyra DD, Gándara L, Di Venosa G, Vallecorsa P, Sáenz D, Calvo G, Batlle A, Buzzola F, Durantini EN, Casas A. Photodynamic inactivation of planktonic and biofilm growing bacteria mediated by a meso-substituted porphyrin bearing four basic amino groups. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2016; 161:222-9. [PMID: 27285813 DOI: 10.1016/j.jphotobiol.2016.05.026] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Revised: 05/15/2016] [Accepted: 05/30/2016] [Indexed: 01/02/2023]
Affiliation(s)
- L Mamone
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina
| | - D D Ferreyra
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, X5804BYA Río Cuarto, Córdoba, Argentina
| | - L Gándara
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina
| | - G Di Venosa
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina
| | - P Vallecorsa
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina
| | - D Sáenz
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina
| | - Gustavo Calvo
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina
| | - A Batlle
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina
| | - F Buzzola
- Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), CONICET-UBA, Argentina
| | - E N Durantini
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, X5804BYA Río Cuarto, Córdoba, Argentina
| | - A Casas
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires CP1120AAF, Argentina.
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69
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Rabinovich IM, Rabinovich OF, Abramova ES, Denisova MA. [Clinical and pathogenetic aspects of various forms of cheilitis]. STOMATOLOGII︠A︡ 2016; 95:67-72. [PMID: 27182564 DOI: 10.17116/stomat201695167-72] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- I M Rabinovich
- Central Research Institute of Dentistry and Maxillofacial Surgery, Moscow, Russia
| | - O F Rabinovich
- Central Research Institute of Dentistry and Maxillofacial Surgery, Moscow, Russia
| | - E S Abramova
- Central Research Institute of Dentistry and Maxillofacial Surgery, Moscow, Russia
| | - M A Denisova
- Central Research Institute of Dentistry and Maxillofacial Surgery, Moscow, Russia
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70
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Preuß A, Bornhütter T, Färber A, Schaller C, Röder B. Photodynamic inactivation of biofilm building microorganisms by photoactive facade paints. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2016; 160:79-85. [PMID: 27101275 DOI: 10.1016/j.jphotobiol.2016.04.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 04/07/2016] [Accepted: 04/07/2016] [Indexed: 01/04/2023]
Abstract
This study was performed as a proof of concept for singlet oxygen generating facade paint as an alternative to conventional biocide containing facade paint for the prevention of biofilm growth on outdoor walls. Biofilms on outdoor walls cause esthetic problems and economic damage. Therefore facade paints often contain biocides. However commercially available biocides may have a series of adverse effects on living organisms as well as harmful environmental effects. Furthermore, biocides are increasingly designed to be more effective and are environmentally persistent. Thus, an eco-friendly and non-harmful to human health alternative to conventional biocides in wall color is strongly recommended. The well-known photosensitizer 5,10,15,20-tetrakis(N-methyl-4-pyridyl)-21H,23H-porphine (TMPyP) was used as an additive in a commercially available facade paint. The generation of singlet molecular oxygen was shown using time resolved 2D measurements of the singlet oxygen luminescence. The photodynamic activity of the photosensitizer in the facade paint was demonstrated by phototoxicity tests with defined mold fungi and a mixture of microorganisms harvested from native outdoor biofilms as model organisms. It was proven in general that it is possible to inhibit the growth of biofilm forming microorganisms growing on solid wall paint surfaces by the cationic photosensitizer TMPyP added to the facade paint using daylight conditions for illumination in 12h light and dark cycles.
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Affiliation(s)
- Annegret Preuß
- Department of Physics, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany.
| | - Tobias Bornhütter
- Department of Physics, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany
| | - Alexander Färber
- Sto SE & Co. KGaA, Ehrenbachstraße 1, D-79780 Stühlingen, Germany
| | | | - Beate Röder
- Department of Physics, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany
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71
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Wang Y, Wu X, Chen J, Amin R, Lu M, Bhayana B, Zhao J, Murray CK, Hamblin MR, Hooper DC, Dai T. Antimicrobial Blue Light Inactivation of Gram-Negative Pathogens in Biofilms: In Vitro and In Vivo Studies. J Infect Dis 2016; 213:1380-7. [PMID: 26908743 DOI: 10.1093/infdis/jiw070] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 02/01/2016] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Biofilms affect >80% bacterial infections in human and are usually difficult to eradicate because of their inherent drug resistance. METHODS We investigated the effectiveness of antimicrobial blue light (aBL) (wavelength, 415 nm) for inactivating Acinetobacter baumannii or Pseudomonas aeruginosa biofilms in 96-well microplates or infected mouse burn wounds. RESULTS In vitro, in 96-well microplates, exposure of 24-hour-old and 72-hour-old A. baumannii biofilms to 432 J/cm(2) aBL resulted in inactivation of 3.59 log10 and 3.18 log10 colony-forming units (CFU), respectively. For P. aeruginosa biofilms, similar levels of inactivation-3.02 log10 and 3.12 log10 CFU, respectively-were achieved. In mouse burn wounds infected with 5 × 10(6) CFU ofA. baumannii, approximately 360 J/cm(2) and 540 J/cm(2) aBL was required to inactivate 3 log10 CFU in biofilms when delivered 24 and 48 hours, respectively, after bacterial inoculation. High-performance liquid chromatography analysis revealed the presence of endogenous porphyrins in both A. baumannii and P. aeruginosa TUNEL assay detected no apoptotic cells in aBL-irradiated mouse skin at up to 24 hours after aBL exposure (540 J/cm(2)). CONCLUSIONS aBL has antimicrobial activity in biofilms ofA. baumannii and P. aeruginosa and is a potential therapeutic approach for biofilm-related infections.
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Affiliation(s)
- Yucheng Wang
- Department of Laser Medicine, Chinese PLA General Hospital, Beijing College of Medicine, Nankai University, Tianjin Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Ximing Wu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Jia Chen
- Shanghai Dermatology Hospital, China Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Rehab Amin
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Min Lu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Brijesh Bhayana
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Jie Zhao
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Clinton K Murray
- Infectious Disease Service, Brooke Army Medical Center, Fort Sam Houston, Texas
| | - Michael R Hamblin
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts
| | - David C Hooper
- Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, Boston
| | - Tianhong Dai
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston
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72
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Tabenski I, Cieplik F, Tabenski L, Regensburger J, Hiller KA, Buchalla W, Maisch T, Späth A. The impact of cationic substituents in phenalen-1-one photosensitizers on antimicrobial photodynamic efficacy. Photochem Photobiol Sci 2016; 15:57-68. [DOI: 10.1039/c5pp00262a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
SAGUA with its guanidinium moiety reaching an efficacy of ≥6log10 steps of bacteria killing at 10 μM after irradiation with blue light (20 mW cm−2) for 60 s (1.2 J cm−2) without exhibiting dark toxicity.
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Affiliation(s)
- Isabelle Tabenski
- Department of Conservative Dentistry and Periodontology
- University Medical Center Regensburg
- Regensburg
- Germany
| | - Fabian Cieplik
- Department of Conservative Dentistry and Periodontology
- University Medical Center Regensburg
- Regensburg
- Germany
| | - Laura Tabenski
- Department of Conservative Dentistry and Periodontology
- University Medical Center Regensburg
- Regensburg
- Germany
| | | | - Karl-Anton Hiller
- Department of Conservative Dentistry and Periodontology
- University Medical Center Regensburg
- Regensburg
- Germany
| | - Wolfgang Buchalla
- Department of Conservative Dentistry and Periodontology
- University Medical Center Regensburg
- Regensburg
- Germany
| | - Tim Maisch
- Department of Dermatology
- University Medical Center Regensburg
- Regensburg
- Germany
| | - Andreas Späth
- Department of Organic Chemistry
- University of Regensburg
- Regensburg
- Germany
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73
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Xu F, Li J, Zhu TT, Yu SS, Zuo C, Yao RS, Qian HS. A new trick (hydroxyl radical generation) of an old vitamin (B2) for near-infrared-triggered photodynamic therapy. RSC Adv 2016. [DOI: 10.1039/c6ra23440b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A new NIR-light-triggered PDT method has been developed using an old vitamin (vitamin B2) integrated with the upconversion nanotechnology.
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Affiliation(s)
- Fang Xu
- Department of Pharmaceutical Engineering
- Hefei University of Technology
- Hefei
- China
| | - Jin Li
- Department of Pharmaceutical Engineering
- Hefei University of Technology
- Hefei
- China
| | - Ting-ting Zhu
- Department of Pharmaceutical Engineering
- Hefei University of Technology
- Hefei
- China
- Department of Chemistry
| | - Sheng-Song Yu
- Department of Chemistry
- University of Science & Technology of China
- Hefei
- China
| | - Chong Zuo
- Department of Pharmaceutical Engineering
- Hefei University of Technology
- Hefei
- China
| | - Ri-sheng Yao
- Department of Pharmaceutical Engineering
- Hefei University of Technology
- Hefei
- China
| | - Hai-sheng Qian
- Department of Pharmaceutical Engineering
- Hefei University of Technology
- Hefei
- China
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74
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Wang KK, Jung SJ, Hwang JW, Kim BJ, Kim DH, Bae IK, Jeong SH, Kim YR. Bactericidal effect through non-uptake pathway with photofunctional silicon polymer that generates reactive oxygen species. J Photochem Photobiol A Chem 2016. [DOI: 10.1016/j.jphotochem.2015.09.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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75
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Schmalz G, Widbiller M, Galler KM. Material Tissue Interaction--From Toxicity to Tissue Regeneration. Oper Dent 2015; 41:117-31. [PMID: 26645359 DOI: 10.2341/15-249-bl] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The topic of material tissue interaction has gained increasing interest over recent decades from both the dental profession and the public. The primary goal initially was to avoid adverse reactions after the application of dental materials. New laboratory test methods have been developed, and currently premarket testing programs, which attempt to guarantee a basic level of patient safety, are legally required worldwide. The dentist is responsible for selecting the correct indication as well as the proper handling of any newly emerging risk. Apart from this phenomenon-oriented "inert materials concept," the "analytical concept" focuses primarily on analyzing the reasons for adverse reactions, and identifying their associated modifying factors, in order to prevent them or to develop new and more biocompatible materials. The "concept of bioactivity" involves addressing the possibility of positively influencing tissue by materials application, such as the generation of tertiary dentin or antibacterial effects. Finally, tissue regeneration may be supported and promoted by the use of various suitable materials (matrices/scaffolds) into which stem cells can migrate or be seeded, leading to cell differentiation and the generation of new tissue. These new dental materials must also fulfill additional requirements such as controlled degradability in order to be suitable for clinical use. Clearly, the field of material tissue interaction is complex and comprises a wide range of issues. To be successful as dentists in the future, practitioners should remain informed of these important new developments and have the argumentative competence to both properly advise and treat their patients.
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76
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Eichner A, Gollmer A, Späth A, Bäumler W, Regensburger J, König B, Maisch T. Fast and effective inactivation of Bacillus atrophaeus endospores using light-activated derivatives of vitamin B2. Photochem Photobiol Sci 2015; 14:387-96. [PMID: 25423452 DOI: 10.1039/c4pp00285g] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Highly resistant endospores may cause severe problems in medicine as well as in the food and packaging industries. We found that bacterial endospores can be inactivated quickly with reactive oxygen species (ROS) that were generated by a new generation of flavin photosensitizers. Flavins like the natural compound vitamin B2 are already known to produce ROS but they show a poor antimicrobial photodynamic killing efficacy due to the lack of positive charges. Therefore we synthesized new flavin photosensitizers that have one (FLASH-01a) or eight (FLASH-07a) positive charges and can hence attach to the negatively charged surface of endospores. In this study we used standardized Bacillus atrophaeus endospores (ATCC 9372) as a biological surrogate model for a proof-of-concept study of photodynamic inactivation experiments using FLASH-01a and FLASH-07a. After incubation of spores with different flavin concentrations, the flavin derivatives were excited with blue light at a light dose of 70 J cm(-2). The inactivation of spores was investigated either in suspension or after attachment to polyethylene terephthalate (PET) surfaces. Incubation of spores suspended in Millipore water with 4 mM FLASH-01a for 10 seconds and irradiation with blue light for 10 seconds caused a biologically relevant decrease of spore survival of 3.5 log10 orders. Using FLASH-07a under the same conditions we achieved a decrease of 4.4 log10 orders. Immobilized spores on PET surfaces were efficiently killed with 7.0 log10 orders using 8 mM FLASH-07a. The total treatment time (incubation + irradiation) was as short as 20 seconds. The results of this study show evidence that endospores can be fastly and effectively inactivated with new generations of flavin photosensitizers that may be useful for industrial or medical applications in the future.
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Affiliation(s)
- Anja Eichner
- Department of Dermatology, Regensburg University Hospital, 93053 Regensburg, Germany.
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Strategies to optimize photosensitizers for photodynamic inactivation of bacteria. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 150:2-10. [DOI: 10.1016/j.jphotobiol.2015.05.010] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 05/13/2015] [Accepted: 05/15/2015] [Indexed: 01/06/2023]
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78
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Cieplik F, Pummer A, Regensburger J, Hiller KA, Späth A, Tabenski L, Buchalla W, Maisch T. The impact of absorbed photons on antimicrobial photodynamic efficacy. Front Microbiol 2015; 6:706. [PMID: 26236292 PMCID: PMC4502582 DOI: 10.3389/fmicb.2015.00706] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 06/26/2015] [Indexed: 12/20/2022] Open
Abstract
Due to increasing resistance of pathogens toward standard antimicrobial procedures, alternative approaches that are capable of inactivating pathogens are necessary in support of regular modalities. In this instance, the photodynamic inactivation of bacteria (PIB) may be a promising alternative. For clinical application of PIB it is essential to ensure appropriate comparison of given photosensitizer (PS)-light source systems, which is complicated by distinct absorption and emission characteristics of given PS and their corresponding light sources, respectively. Consequently, in the present study two strategies for adjustment of irradiation parameters were evaluated: (i) matching energy doses applied by respective light sources (common practice) and (ii) by development and application of a formula for adjusting the numbers of photons absorbed by PS upon irradiation by their corresponding light sources. Since according to the photodynamic principle one PS molecule is excited by the absorption of one photon, this formula allows comparison of photodynamic efficacy of distinct PS per excited molecule. In light of this, the antimicrobial photodynamic efficacy of recently developed PS SAPYR was compared to that of clinical standard PS Methylene Blue (MB) regarding inactivation of monospecies biofilms formed by Enterococcus faecalis and Actinomyces naeslundii whereby evaluating both adjustment strategies. PIB with SAPYR exhibited CFU-reductions of 5.1 log10 and 6.5 log10 against E. faecalis and A. naeslundii, respectively, which is declared as a disinfectant efficacy. In contrast, the effect of PIB with MB was smaller when the applied energy dose was adjusted compared to SAPYR (CFU-reductions of 3.4 log10 and 4.2 log10 against E. faecalis and A. naeslundii), or there was even no effect at all when the number of absorbed photons was adjusted compared to SAPYR. Since adjusting the numbers of absorbed photons is the more precise and adequate method from a photophysical point of view, this strategy should be considered in further studies when antimicrobial efficacy rates of distinct PS-light source systems are compared.
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Affiliation(s)
- Fabian Cieplik
- Department of Conservative Dentistry and Periodontology, University Medical Center Regensburg Regensburg, Germany
| | - Andreas Pummer
- Department of Conservative Dentistry and Periodontology, University Medical Center Regensburg Regensburg, Germany
| | | | - Karl-Anton Hiller
- Department of Conservative Dentistry and Periodontology, University Medical Center Regensburg Regensburg, Germany
| | - Andreas Späth
- Department of Organic Chemistry, University of Regensburg Regensburg, Germany
| | - Laura Tabenski
- Department of Conservative Dentistry and Periodontology, University Medical Center Regensburg Regensburg, Germany
| | - Wolfgang Buchalla
- Department of Conservative Dentistry and Periodontology, University Medical Center Regensburg Regensburg, Germany
| | - Tim Maisch
- Department of Dermatology, University Medical Center Regensburg Regensburg, Germany
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79
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Maisch T. Resistance in antimicrobial photodynamic inactivation of bacteria. Photochem Photobiol Sci 2015; 14:1518-26. [PMID: 26098395 DOI: 10.1039/c5pp00037h] [Citation(s) in RCA: 169] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Antibiotics have increasingly lost their impact to kill bacteria efficiently during the last 10 years. The emergence and dissemination of superbugs with resistance to multiple antibiotic classes have occurred among Gram-positive and Gram-negative strains including Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter strains. These six superbugs can "escape" more or less any single kind of antibiotic treatment. That means bacteria are very good at developing resistance against antibiotics in a short time. One new approach is called photodynamic antimicrobial chemotherapy (PACT) which already has demonstrated an efficient antimicrobial efficacy among multi-resistant bacteria. Until now it has been questionable if bacteria can develop resistance against PACT. This perspective summarises the current knowledge about the susceptibility of bacteria towards oxidative stress and sheds some light on possible strategies of the development of photodynamic inactivation of bacteria (PACT)-induced oxidative stress resistance by bacteria.
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Affiliation(s)
- Tim Maisch
- Department of Dermatology, Antimicrobial Photodynamic and Cold Plasma Research Unit, University Hospital Regensburg, Regensburg, Germany.
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80
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Vohra F, Al-Rifaiy MQ, Lillywhite G, Abu Hassan MI, Javed F. Efficacy of mechanical debridement with adjunct antimicrobial photodynamic therapy for the management of peri-implant diseases: a systematic review. Photochem Photobiol Sci 2015; 13:1160-8. [PMID: 24924586 DOI: 10.1039/c4pp00083h] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The aim was to assess whether or not mechanical debridement with adjunct antimicrobial photodynamic therapy (aPDT) is effective for the management of peri-implant diseases. The addressed focused question was "Is mechanical debridement with adjunct aPDT more effective in treating peri-implant diseases as compared to when mechanical debridement is used alone?" PubMed/MEDLINE and Google-Scholar databases were searched from 1994 till April 2014 using different combinations of the following keywords: antimicrobial photodynamic therapy; bone loss; light activated disinfection; mechanical debridement; and peri-implant diseases. Review articles, case-reports, commentaries, letters to the editor, unpublished articles and articles published in languages other than English were excluded. Twelve studies (six clinical and six experimental) were included. In the clinical and experimental studies, 15-80 implants and 18-150 implants respectively were used. Laser wavelengths, duration of irradiation and power output ranged between 625 nm-830 nm, 10 s-300 s, and 30 mW-200 mW, respectively. Four studies reported mechanical debridement with adjunct aPDT to be effective in the treatment of peri-implant diseases; however, the benefits of aPDT were comparable with conventional treatments. Two studies reported aPDT to reduce bacteria more than when the laser and the photosensitizer were applied alone. In two studies, chemical disinfection and aPDT showed comparable outcomes in terms of bacterial disinfection. In two experimental studies, aPDT was shown to improve bone to implant contact and re-osseointegration. Efficacy of mechanical debridement with adjunct aPDT for the management of peri-implant diseases remains debatable.
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Affiliation(s)
- Fahim Vohra
- Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
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81
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Maisch T, Eichner A, Späth A, Gollmer A, König B, Regensburger J, Bäumler W. Fast and effective photodynamic inactivation of multiresistant bacteria by cationic riboflavin derivatives. PLoS One 2014; 9:e111792. [PMID: 25469700 PMCID: PMC4254278 DOI: 10.1371/journal.pone.0111792] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 10/01/2014] [Indexed: 01/27/2023] Open
Abstract
Photodynamic inactivation of bacteria (PIB) proves to be an additional method to kill pathogenic bacteria. PIB requires photosensitizer molecules that effectively generate reactive oxygen species like singlet oxygen when exposed to visible light. To allow a broad application in medicine, photosensitizers should be safe when applied in humans. Substances like vitamin B2, which are most likely safe, are known to produce singlet oxygen upon irradiation. In the present study, we added positive charges to flavin derivatives to enable attachment of these molecules to the negatively charged surface of bacteria. Two of the synthesized flavin derivatives showed a high quantum yield of singlet oxygen of approximately 75%. Multidrug resistant bacteria like MRSA (Methicillin resistant Staphylococcus aureus), EHEC (enterohemorrhagic Escherichia coli), Pseudomonas aeruginosa, and Acinetobacter baumannii were incubated with these flavin derivatives in vitro and were subsequently irradiated with visible light for seconds only. Singlet oxygen production in bacteria was proved by detecting its luminescence at 1270 nm. After irradiation, the number of viable bacteria decreased up to 6 log10 steps depending on the concentration of the flavin derivatives and the light dosimetry. The bactericidal effect of PIB was independent of the bacterial type and the corresponding antibiotic resistance pattern. In contrast, the photosensitizer concentration and light parameters used for bacteria killing did not affect cell viability of human keratinocytes (therapeutic window). Multiresistant bacteria can be safely and effectively killed by a combination of modified vitamin B2 molecules, oxygen and visible light, whereas normal skin cells survive. Further work will include these new photosensitizers for topical application to decolonize bacteria from skin and mucosa.
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Affiliation(s)
- Tim Maisch
- Department of Dermatology, University Hospital Regensburg, Regensburg, Germany
| | - Anja Eichner
- Department of Dermatology, University Hospital Regensburg, Regensburg, Germany
- * E-mail:
| | - Andreas Späth
- Institute of Organic Chemistry, University of Regensburg, Regensburg, Germany
| | - Anita Gollmer
- Department of Dermatology, University Hospital Regensburg, Regensburg, Germany
| | - Burkhard König
- Institute of Organic Chemistry, University of Regensburg, Regensburg, Germany
| | | | - Wolfgang Bäumler
- Department of Dermatology, University Hospital Regensburg, Regensburg, Germany
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82
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Beirão S, Fernandes S, Coelho J, Faustino MAF, Tomé JPC, Neves MGPMS, Tomé AC, Almeida A, Cunha A. Photodynamic inactivation of bacterial and yeast biofilms with a cationic porphyrin. Photochem Photobiol 2014; 90:1387-96. [PMID: 25112506 DOI: 10.1111/php.12331] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 08/05/2014] [Indexed: 12/26/2022]
Abstract
The efficiency of 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrin tetra-iodide (Tetra-Py(+)-Me) in the photodynamic inactivation of single-species biofilms of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans and mixed biofilms of S. aureus and C. albicans was evaluated. The effect on the extracellular matrix of P. aeruginosa was also assessed. Irradiation with white light up to an energy dose of 64.8 J cm(-2) in the presence of 20 μm of Tetra-Py(+)-Me caused significant inactivation in all single-species biofilms (3-6 log reductions), although the susceptibility was attenuated in relation to planktonic cells. In mixed biofilms, the inactivation of S. aureus was as efficient as in single-species biofilms but the susceptibility of C. albicans decreased. In P. aeruginosa biofilms, a reduction of 81% in the polysaccharide content of the matrix was observed after treatment with a 20 μm PS concentration and a total light dose of 64.8 J cm(-2). The results show that the Tetra-Py(+)-Me causes significant inactivation of the microorganisms, either in biofilms or in the planktonic form, and demonstrate that polysaccharides of the biofilm matrix may be a primary target of photodynamic damage.
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Affiliation(s)
- Sandra Beirão
- Department of Biology and CESAM, University of Aveiro, Aveiro, Portugal
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83
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Novel Broad-Spectrum Antimicrobial Photoinactivation of In Situ Oral Biofilms by Visible Light plus Water-Filtered Infrared A. Appl Environ Microbiol 2014; 80:7324-36. [PMID: 25239897 DOI: 10.1128/aem.02490-14] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 09/13/2014] [Indexed: 11/20/2022] Open
Abstract
Antimicrobial photodynamic therapy (APDT) has gained increased attention as an alternative treatment approach in various medical fields. However, the effect of APDT using visible light plus water-filtered infrared A (VIS + wIRA) on oral biofilms remains unexplored. For this purpose, initial and mature oral biofilms were obtained in situ; six healthy subjects wore individual upper jaw acrylic devices with bovine enamel slabs attached to their proximal sites for 2 h or 3 days. The biofilms were incubated with 100 μg ml(-1) toluidine blue O (TB) or chlorin e6 (Ce6) and irradiated with VIS + wIRA with an energy density of 200 mW cm(-2) for 5 min. After cultivation, the CFU of half of the treated biofilm samples were quantified, whereas following live/dead staining, the other half of the samples were monitored by confocal laser scanning microscopy (CLSM). TB- and Ce6-mediated APDT yielded a significant decrease of up to 3.8 and 5.7 log10 CFU for initial and mature oral biofilms, respectively. Quantification of the stained photoinactivated microorganisms confirmed these results. Overall, CLSM revealed the diffusion of the tested photosensitizers into the deepest biofilm layers after exposure to APDT. In particular, Ce6-aided APDT presented elevated permeability and higher effectiveness in eradicating 89.62% of biofilm bacteria compared to TB-aided APDT (82.25%) after 3 days. In conclusion, antimicrobial photoinactivation using VIS + wIRA proved highly potent in eradicating oral biofilms. Since APDT excludes the development of microbial resistance, it could supplement the pharmaceutical treatment of periodontitis or peri-implantitis.
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84
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Abstract
The emergence of microbial resistance is becoming a global problem in clinical and environmental areas. As such, the development of drugs with novel modes of action will be vital to meet the threats created by the rise in microbial resistance. Microbial photodynamic inactivation is receiving considerable attention for its potentialities as a new antimicrobial treatment. This review addresses the interactions between photosensitizers and bacterial cells (binding site and cellular localization), the ultrastructural, morphological and functional changes observed at initial stages and during the course of photodynamic inactivation, the oxidative alterations in specific molecular targets, and a possible development of resistance.
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85
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Cieplik F, Tabenski L, Buchalla W, Maisch T. Antimicrobial photodynamic therapy for inactivation of biofilms formed by oral key pathogens. Front Microbiol 2014; 5:405. [PMID: 25161649 PMCID: PMC4130309 DOI: 10.3389/fmicb.2014.00405] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 07/18/2014] [Indexed: 12/24/2022] Open
Abstract
With increasing numbers of antibiotic-resistant pathogens all over the world there is a pressing need for strategies that are capable of inactivating biofilm-state pathogens with less potential of developing resistances in pathogens. Antimicrobial strategies of that kind are especially needed in dentistry in order to avoid the usage of antibiotics for treatment of periodontal, endodontic or mucosal topical infections caused by bacterial or yeast biofilms. One possible option could be the antimicrobial photodynamic therapy (aPDT), whereby the lethal effect of aPDT is based on the principle that visible light activates a photosensitizer (PS), leading to the formation of reactive oxygen species, e.g., singlet oxygen, which induce phototoxicity immediately during illumination. Many compounds have been described as potential PS for aPDT against bacterial and yeast biofilms so far, but conflicting results have been reported. Therefore, the aim of the present review is to outline the actual state of the art regarding the potential of aPDT for inactivation of biofilms formed in vitro with a main focus on those formed by oral key pathogens and structured regarding the distinct types of PS.
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Affiliation(s)
- Fabian Cieplik
- Department of Operative Dentistry and Periodontology, University Medical Center Regensburg Regensburg, Germany
| | - Laura Tabenski
- Department of Operative Dentistry and Periodontology, University Medical Center Regensburg Regensburg, Germany
| | - Wolfgang Buchalla
- Department of Operative Dentistry and Periodontology, University Medical Center Regensburg Regensburg, Germany
| | - Tim Maisch
- Department of Dermatology, University Medical Center Regensburg Regensburg, Germany
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86
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Späth A, Leibl C, Cieplik F, Lehner K, Regensburger J, Hiller KA, Bäumler W, Schmalz G, Maisch T. Improving Photodynamic Inactivation of Bacteria in Dentistry: Highly Effective and Fast Killing of Oral Key Pathogens with Novel Tooth-Colored Type-II Photosensitizers. J Med Chem 2014; 57:5157-68. [DOI: 10.1021/jm4019492] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Andreas Späth
- Department
of Organic Chemistry, University of Regensburg, Regensburg, Germany
| | | | | | - Karin Lehner
- Department
of Organic Chemistry, University of Regensburg, Regensburg, Germany
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