scholarly journals Phenalen-1-One-Mediated Antimicrobial Photodynamic Therapy and Chlorhexidine Applied to a Novel Caries Biofilm Model

2018 ◽  
Vol 52 (6) ◽  
pp. 447-453 ◽  
Author(s):  
Fabian Cieplik ◽  
Fabian Wimmer ◽  
Denise Muehler ◽  
Thomas Thurnheer ◽  
Georgios N. Belibasakis ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Streptococcus Mutans ◽  
High Throughput ◽  
High Throughput Screening ◽  
Antimicrobial Efficacy ◽  
Antimicrobial Photodynamic Therapy ◽  
Actinomyces Naeslundii ◽  
Biofilm Model ◽  
Pronounced Reduction

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.

scholarly journals Antimicrobial efficacy of neem and liquorice with chlorhexidine on Streptococcus sanguis, Streptococcus mutans, Lactobacillus and Actinomyces naeslundii – An In Vitro Study

2020 ◽  
Author(s):  
Saad M Alqahtani
Keyword(s):  
Streptococcus Mutans ◽  
Inhibitory Concentration ◽  
Brain Heart Infusion ◽  
In Vitro Study ◽  
Alcoholic Solution ◽  
Antimicrobial Efficacy ◽  
Streptococcus Sanguis ◽  
Actinomyces Naeslundii ◽  
Culture Suspension

AbstractThe study was to formulate 2% neem and 2% liquorice mouthwashes and to compare the antimicrobial efficacy of these mouthwashes with the standard 0.2% chlorhexidine mouthwash. Alcoholic solution was prepared and added to neem mixture and liquorice mixture separately and made up to a volume of 16000 ml with purified water. Nine dilutions of each drug were done with Brain heart infusion broth (BHI) for MIC. Culture suspension was added in each serially diluted tube of 200 μl. The tubes were incubated for 24 hours and observed for turbidity. Minimum inhibitory concentration (MIC) of 2% neem, 2% liquorice and 0.2% chlorhexidine against Lactobacillus, Actinomyces naeslundii, Streptococcus sanguis, Streptococcus mutans is determined by serial dilution analysis. Streptococcus mutans shows sensitivity to all three mouthwashes at a concentration starting from 0.2 μg/ml. Lactobacillus shows sensitivity to neem and chlorhexidine mouthwashes at a concentration starting from 1.6 μg/ml, whereas liquorice is effective at a concentration starting from 3.125 μg/ml. Streptococcus sanguis shows sensitivity to chlorhexidine and liquorice mouthwashes at a concentration starting from 25 μg/ml, whereas it shows sensitivity to neem at a concentration starting from 50 μg/ml. Actinomyces naeslundii shows sensitivity to chlorhexidine and neem mouthwashes at a concentration starting from 1.6 μg/ml, whereas it shows sensitivity to liquorice at a concentration starting from 3.125μg/ml. Analysis showed an inhibition of all the four strains by the mouthwashes. The MIC for the studied mouthwashes was found to be similar to that of 0.2% chlorhexidine.

scholarly journals Propolis nanoparticle enhances the potency of antimicrobial photodynamic therapy against Streptococcus mutans in a synergistic manner

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shima Afrasiabi ◽  
Maryam Pourhajibagher ◽  
Nasim Chiniforush ◽  
Abbas Bahador
Keyword(s):  
Photodynamic Therapy ◽  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Synergistic Effects ◽  
Fibroblast Cell ◽  
Human Gingival Fibroblast ◽  
Gingival Fibroblast ◽  
Antimicrobial Photodynamic Therapy ◽  
The Individual

Abstract Less invasive removal approaches have been recommended for deep caries lesions. Antimicrobial photodynamic therapy (aPDT) and propolis nanoparticle (PNP) are highlighted for the caries management plan. Evidence is lacking for an additive effect of combination PNP with photosensitizer (PS) in aPDT. This study aimed to investigate the individual and synergistic effects of chlorophyllin-phycocyanin mixture (PhotoActive+) and toluidine blue O (TBO) as PSs in combination with PNP in the aPDT process (aPDTplus) against major important virulence factors of Streptococcus mutans. Following characterization, biocompatibility of the PSs alone, or in combination with PNP were investigated on human gingival fibroblast cell. The in vitro synergy of PhotoActive+ or TBO and PNP was evaluated by the checkerboard method. The bacteria's virulence properties were surveyed in the presence of the PSs, individually as well as in combination. When the PSs were examined in combination (synergistic effect, FIC Index < 0.5), a stronger growth inhibitory activity was exhibited than the individual PSs. The biofilm formation, as well as genes involved in biofilm formation, showed greater suppression when the PSs were employed in combination. Overall, the results of this study suggest that the combination of PhotoActive+ or TBO with PNP with the least cytotoxicity effects and the highest antimicrobial activites would improve aPDT outcomes, leading to synergistic effects and impairing the virulence of S. mutans.

The impact of antimicrobial photodynamic therapy on Streptococcus mutans in an artificial biofilm model

2010 ◽  
Author(s):  
Martin Schneider ◽  
Gregor Kirfel ◽  
Felix Krause ◽  
Michael Berthold ◽  
Olivier Brede ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Streptococcus Mutans ◽  
Antimicrobial Photodynamic Therapy ◽  
Biofilm Model ◽  
Artificial Biofilm ◽  
The Impact

scholarly journals A high-throughput screening method for evolving a demethylase enzyme with improved and new functionalities

2020 ◽  
Author(s):  
Yuru Wang ◽  
Christopher D Katanski ◽  
Christopher Watkins ◽  
Jessica N Pan ◽  
Qing Dai ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Screening Method ◽  
Targeted Mutagenesis ◽  
Rna Repair ◽  
Dna And Rna ◽  
Modified Dna ◽  
Dna Substrates ◽  
Trna Sequencing

Abstract AlkB is a DNA/RNA repair enzyme that removes base alkylations such as N1-methyladenosine (m1A) or N3-methylcytosine (m3C) from DNA and RNA. The AlkB enzyme has been used as a critical tool to facilitate tRNA sequencing and identification of mRNA modifications. As a tool, AlkB mutants with better reactivity and new functionalities are highly desired; however, previous identification of such AlkB mutants was based on the classical approach of targeted mutagenesis. Here, we introduce a high-throughput screening method to evaluate libraries of AlkB variants for demethylation activity on RNA and DNA substrates. This method is based on a fluorogenic RNA aptamer with an internal modified RNA/DNA residue which can block reverse transcription or introduce mutations leading to loss of fluorescence inherent in the cDNA product. Demethylation by an AlkB variant eliminates the blockage or mutation thereby restores the fluorescence signals. We applied our screening method to sites D135 and R210 in the Escherichia coli AlkB protein and identified a variant with improved activity beyond a previously known hyperactive mutant toward N1-methylguanosine (m1G) in RNA. We also applied our method to O6-methylguanosine (O6mG) modified DNA substrates and identified candidate AlkB variants with demethylating activity. Our study provides a high-throughput screening method for in vitro evolution of any demethylase enzyme.

scholarly journals Efficiency of Antimicrobial Photodynamic Therapy with Photodithazine® on MSSA and MRSA Strains

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 869
Author(s):  
Beatriz Müller Nunes Souza ◽  
Juliana Guerra Pinto ◽  
André Henrique Correia Pereira ◽  
Alejandro Guillermo Miñán ◽  
Juliana Ferreira-Strixino
Keyword(s):  
Staphylococcus Aureus ◽  
Photodynamic Therapy ◽  
Antimicrobial Photodynamic Therapy ◽  
Bacterial Inactivation ◽  
Bacterial Reduction ◽  
Complete Inactivation ◽  
Opportunistic Bacteria ◽  
Significant Difference ◽  
Mrsa Strains

Staphylococccus aureus is a ubiquitous and opportunistic bacteria associated with high mortality rates. Antimicrobial photodynamic therapy (aPDT) is based on the application of a light source and a photosensitizer that can interact with molecular oxygen, forming Reactive Oxygen Species (ROS) that result in bacterial inactivation. This study aimed to analyze, in vitro, the action of aPDT with Photodithazine® (PDZ) in methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) strains. The strains were incubated with PDZ at 25, 50, 75, and 100 mg/L for 15 min and irradiated with fluences of 25, 50, and 100 J/cm2. The internalization of PDZ was evaluated by confocal microscopy, the bacterial growth by counting the number of colony-forming units, as well as the bacterial metabolic activity post-aPDT and the production of ROS. In both strains, the photosensitizer was internalized; the production of ROS increased when the aPDT was applied; there was a bacterial reduction compared to the control at all the evaluated fluences and concentrations; and, in most parameters, it was obtained complete inactivation with significant difference (p < 0.05). The implementation of aPDT with PDZ in clinical strains of S. aureus has resulted in its complete inactivation, including the MRSA strains.

scholarly journals Investigating Molecular Mechanisms of Immunotoxicity and the Utility of ToxCast for Immunotoxicity Screening of Chemicals Added to Food

2021 ◽  
Vol 18 (7) ◽  
pp. 3332
Author(s):  
Olga V. Naidenko ◽  
David Q. Andrews ◽  
Alexis M. Temkin ◽  
Tasha Stoiber ◽  
Uloma Igara Uche ◽  
...  
Keyword(s):  
Immune System ◽  
High Throughput ◽  
Environmental Protection Agency ◽  
High Throughput Screening ◽  
Molecular Mechanisms ◽  
Specific Activity ◽  
Laboratory Animals ◽  
In Vitro Assays ◽  
Toxicological Studies

The development of high-throughput screening methodologies may decrease the need for laboratory animals for toxicity testing. Here, we investigate the potential of assessing immunotoxicity with high-throughput screening data from the U.S. Environmental Protection Agency ToxCast program. As case studies, we analyzed the most common chemicals added to food as well as per- and polyfluoroalkyl substances (PFAS) shown to migrate to food from packaging materials or processing equipment. The antioxidant preservative tert-butylhydroquinone (TBHQ) showed activity both in ToxCast assays and in classical immunological assays, suggesting that it may affect the immune response in people. From the PFAS group, we identified eight substances that can migrate from food contact materials and have ToxCast data. In epidemiological and toxicological studies, PFAS suppress the immune system and decrease the response to vaccination. However, most PFAS show weak or no activity in immune-related ToxCast assays. This lack of concordance between toxicological and high-throughput data for common PFAS indicates the current limitations of in vitro screening for analyzing immunotoxicity. High-throughput in vitro assays show promise for providing mechanistic data relevant for immune risk assessment. In contrast, the lack of immune-specific activity in the existing high-throughput assays cannot validate the safety of a chemical for the immune system.

scholarly journals High-throughput screening and rational design of biofunctionalized surfaces with optimized biocompatibility and antimicrobial activity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhou Fang ◽  
Junjian Chen ◽  
Ye Zhu ◽  
Guansong Hu ◽  
Haoqian Xin ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
High Throughput ◽  
High Throughput Screening ◽  
Rational Design ◽  
Click Reaction ◽  
Reaction Times ◽  
Great Promise ◽  
Biomaterial Surfaces

AbstractPeptides are widely used for surface modification to develop improved implants, such as cell adhesion RGD peptide and antimicrobial peptide (AMP). However, it is a daunting challenge to identify an optimized condition with the two peptides showing their intended activities and the parameters for reaching such a condition. Herein, we develop a high-throughput strategy, preparing titanium (Ti) surfaces with a gradient in peptide density by click reaction as a platform, to screen the positions with desired functions. Such positions are corresponding to optimized molecular parameters (peptide densities/ratios) and associated preparation parameters (reaction times/reactant concentrations). These parameters are then extracted to prepare nongradient mono- and dual-peptide functionalized Ti surfaces with desired biocompatibility or/and antimicrobial activity in vitro and in vivo. We also demonstrate this strategy could be extended to other materials. Here, we show that the high-throughput versatile strategy holds great promise for rational design and preparation of functional biomaterial surfaces.

scholarly journals Photodynamic Therapy Combined with Antibiotics or Antifungals against Microorganisms That Cause Skin and Soft Tissue Infections: A Planktonic and Biofilm Approach to Overcome Resistances

2021 ◽  
Vol 14 (7) ◽  
pp. 603
Author(s):  
Vanesa Pérez-Laguna ◽  
Isabel García-Luque ◽  
Sofía Ballesta ◽  
Antonio Rezusta ◽  
Yolanda Gilaberte
Keyword(s):  
Photodynamic Therapy ◽  
Soft Tissues ◽  
Combined Treatment ◽  
Resistance Pattern ◽  
Antimicrobial Photodynamic Therapy ◽  
Antimicrobial Drugs ◽  
Bacteria And Fungi ◽  
High Level ◽  
Selection Of

The present review covers combination approaches of antimicrobial photodynamic therapy (aPDT) plus antibiotics or antifungals to attack bacteria and fungi in vitro (both planktonic and biofilm forms) focused on those microorganisms that cause infections in skin and soft tissues. The combination can prevent failure in the fight against these microorganisms: antimicrobial drugs can increase the susceptibility of microorganisms to aPDT and prevent the possibility of regrowth of those that were not inactivated during the irradiation; meanwhile, aPDT is effective regardless of the resistance pattern of the strain and their use does not contribute to the selection of antimicrobial resistance. Additive or synergistic antimicrobial effects in vitro are evaluated and the best combinations are presented. The use of combined treatment of aPDT with antimicrobials could help overcome the difficulty of fighting high level of resistance microorganisms and, as it is a multi-target approach, it could make the selection of resistant microorganisms more difficult.

scholarly journals Efficacy of Toluidine Blue—Mediated Antimicrobial Photodynamic Therapy on Candida spp. A Systematic Review

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 349
Author(s):  
Rafał Wiench ◽  
Dariusz Skaba ◽  
Jacek Matys ◽  
Kinga Grzech-Leśniak
Keyword(s):  
Photodynamic Therapy ◽  
Toluidine Blue ◽  
Randomized Clinical Trials ◽  
Oral Candidiasis ◽  
In Vitro Studies ◽  
Cochrane Central Register ◽  
Antimicrobial Photodynamic Therapy ◽  
Candida Spp ◽  
Denture Stomatitis

The effectiveness of antimicrobial photodynamic therapy (aPDT) in the treatment of oral yeast infections was examined many times in recent years. The authors of this review tried to address the question: “Should TBO (toluidine blue ortho)-mediated aPDT be considered a possible alternative treatment for oral candidiasis?”. PubMed/Medline and the Cochrane Central Register of Controlled Trials (CEN-TRAL) databases were searched from 1997 up to the 27th of October 2020 using a combination of the following keywords: (Candida OR Candidiasis oral OR Candidosis oral OR denture stomatitis) AND (toluidine blue OR photodynamic therapy OR aPDT OR photodynamic antimicrobial chemotherapy OR PACT OR photodynamic inactivation OR PDI). Animal studies or in vitro studies involving Candida albicans (C. albicans) and/or nonalbicans stain, randomized clinical trials (RCT) involving patients with oral candidiasis or denture stomatitis published solely in English language were included. Candida elimination method in animal, in vitro studies and RCT used was TBO-mediated aPDT. Exactly 393 studies were taken into consideration. Then, after analyzing titles and abstracts of said studies, 361 were excluded. Only 32 studies ended up being selected for in-depth screening, after which 21 of them were included in this study. All studies reported the antifungal effectiveness of aPDT with TBO against C. albicans and non-albicans Candida. In studies conducted with planktonic cells, only one study showed eradication of C. albicans. All others showed partial elimination and only one of them was not statistically significant. Experiments on yeast biofilms, in all cases, showed partial, statistically significant cell growth inhibition and weight reduction (a reduction in the number of cells—mainly hyphae) and the mass of extracellular polymeric substance (EPS). In vivo aPDT mediated by TBO exhibits antifungal effects against oral Candida spp.; however, its clinical effectiveness as a potent therapeutic strategy for oral yeast infections requires further investigation.

Sign in / Sign up

Export Citation Format

Share Document