Antimicrobial Photodynamic Therapy in the Nasal Decolonization of Maintenance Hemodialysis Patients: A Pilot Randomized Trial.

RATIONALE & OBJECTIVE: Infections are an important cause of mortality among patients receiving maintenance hemodialysis. Staphylococcus aureus is a frequent etiological agent, and previous nasal colonization is a risk factor for infection. Repeated antimicrobial decolonization reduces infection in this population but can induce antibiotic resistance. We compared photodynamic therapy, a promising bactericidal treatment that does not induce resistance, to mupirocin treatment among nasal carriers of S aureus. STUDY DESIGN: Randomized controlled pilot study. SETTING & PARTICIPANTS: 34 patients receiving maintenance hemodialysis who had nasal carriage of S aureus. INTERVENTIONS: Patients were randomly assigned to decolonization with a single application of photodynamic therapy (wavelength of 660nm, 400mW/cm2, 300 seconds, methylene blue 0.01%) or with a topical mupirocin regimen (twice a day for 5 days). OUTCOME: Nasal swabs were collected at time 0 (when the carrier state was identified), directly after treatment completion, 1 month after treatment, and 3 months after treatment. Bacterial isolates were subjected to proteomic analysis to identify the species present, and antimicrobial susceptibility was characterized. RESULTS: All 17 participants randomized to photodynamic therapy and 13 of 17 (77%) randomized to mupirocin were adherent to treatment. Directly after treatment was completed, 12 participants receiving photodynamic therapy (71%) and 13 participants treated with mupirocin (77%) had cultures that were negative for S aureus (risk ratio, 0.92 [95% CI, 0.61-1.38]; P=0.9). Of the patients who had negative cultures directly after completion of photodynamic therapy, 67% were recolonized within 3 months. There were no adverse events in the photodynamic therapy group. LIMITATIONS: Testing was restricted to assessing nasal colonization; infectious complications were not assessed. CONCLUSIONS: Photodynamic therapy is a feasible approach to treating nasal carriage of S aureus. Future larger studies should be conducted to determine whether photodynamic therapy is equivalent to the standard of care with mupirocin. FUNDING: Government grant (National Council for Scientific and Technological Development process 3146682020-9). TRIAL REGISTRATION: Registered at ClinicalTrials.gov with study number NCT04047914.

The influence of growth medium on the photodynamic susceptibility of Aggregatibacter actinomycetemcomitans to antimicrobial blue light.

The aim of this study was to investigate whether antimicrobial blue light (aBL) can cause the death of Aggregatibacter actinomycetemcomitans (A.a) and to determine the influence of different culture media, specifically brain heart infusion and blood agar, on bacterial survival fraction. An LED emitting at 403 ± 15 nm, with a radiant power of 1W, irradiance of 588.2 mW/cm2, and an irradiation time of 0 min, 1 min, 5 min, 10 min, 30 min, and 60 min, was used. The plates were incubated in microaerophilic conditions at 37 °C for 48 h, and the colony-forming units were counted. The photosensitizers were investigated using spectroscopy and fluorescence microscopy. There was no significant difference between the culture media (p > 0.05). However, a statistical reduction in both media was observed at 30 min (1058 J/cm2) (p < 0.05). The findings of this study suggest that aBL has the potential to kill bacteria regardless of the culture media used. Light therapy could be a promising and cost-effective strategy for preventing periodontal disease when used in combination with mechanical plaque control.

A common oral pathogen Porphyromonas gingivalis induces myocarditis in rats.

AIM: To evaluate whether Porphyromonas gingivalis (P. gingivalis) inoculation could induce cardiac remodelling in rats. MATERIALS AND METHODS: The study was conducted on 33 Wistar rats, which were distributed in the following experimental groups: not inoculated; inoculated with 1 × 108 CFU/ml of bacteria; inoculated with 3 × 108 CFU/ml of bacteria. The animals were inoculated at baseline and on the 15th day of follow-up. Blood collection was performed at baseline and 60 min after each inoculation. At 29 days, the animals were subjected to echocardiography and at 30 days to haemodynamic studies before sacrificing them. RESULTS: Impact of the bacteria was more evident in rats that received higher P. gingivalis concentration. Thus, 3 × 108 CFU/ml of bacteria increased the rectal temperature and water content in the lung as well as myocardial necrosis and fibrosis. P. gingivalis induced the intensification of DNA fragmentation and increased the levels of malondialdehyde, oxidized proteins, and macrophage expression in the myocardium. These findings were associated with lower LV isovolumetric relaxation time, +dP/dt, -dP/dt, and higher end-diastolic pressure. CONCLUSIONS: P. gingivalis bacteraemia is significantly associated with adverse cardiac remodelling and may play a biological role in the genesis of heart failure.

Photobiomodulation therapy preconditioning modifies nitric oxide pathway and oxidative stress in human-induced pluripotent stem cell-derived ventricular cardiomyocytes treated with doxorubicin.

Doxorubicin (DOX) is an anthracycline antibiotic that exhibits high heart toxicity. Human-induced pluripotent stem cell-derived ventricular cardiomyocytes (hiPSC-vCMs) are important in vitro models for testing drug cardiotoxicity. Photobiomodulation therapy (PBMT) is a non-invasive therapy that stimulates cells growth and self-repair using light irradiation. This study aimed to investigate the in vitro effects of PBMT preconditioning on cardiotoxicity induced by DOX. HiPSC-vCMs were treated with PBMT for 500 s, followed by the addition of 2 µM DOX. LED irradiation preconditioning parameters were at 660 nm with an irradiance of 10 mW/cm2, performing 5 J/cm2, followed by 24-h DOX exposure (2 µM). Human iPSC-vCMs treated with 2 µM DOX or irradiated with PBMT composed the second and third groups, respectively. The control group did neither receive PBMT preconditioning nor DOX and was irradiated with a white standard lamp. Cells from all groups were collected to perform mRNA and miRNA expressions quantification. PBMT, when applied before the DOX challenge, restored the viability of hiPSC-vCMs and reduced ROS levels. Although downregulated by DOX, myocardial UCP2 mRNA expression presented marked upregulation after PBMT preconditioning. Expression of eNOS and UCP2 mRNA and NO production were decreased after DOX exposure, and PBMT preconditioning before the DOX challenge reversed these changes. Moreover, our data indicated that PBMT preconditioning lowered the miR-24 expression. Our data suggested that PBMT preconditioning ameliorated in vitro DOX-induced cardiotoxicity on transcription level, restoring NO levels and reducing oxidative stress.

Effect of antimicrobial photodynamic therapy with red led and methylene blue on the reduction of halitosis: controlled microbiological clinical trial.

To determine the effect of antimicrobial photodynamic therapy (aPDT) using a red light-emitting diode (LED) on the reduction of halitosis and microbiological levels in the tongue coating immediately after irradiation, 7, 14, and 30 days after treatment. Forty-five young adults diagnosed with halitosis were allocated to three groups: G1, aPDT with 0.005% methylene blue and red LED (660 nm, four irradiation points, 90 s per point, power of 400 mW, 36 J per point, radiant exposure of 95 J/cm2, continuous wave); G2, tongue scraping; and G3, tongue scraping and aPDT. Gas chromatography was performed before and immediately after treatment, as well as at the different follow-up times. Microbiological samples were collected at the same times from the dorsum of the tongue, and bacteria were quantified in the samples using real-time PCRq. The Wilcoxon test was used for the intragroup analyses, and the Kruskal-Wallis test was used for the intergroup analyses. In the intragroup analyses, differences were found before and immediately after treatment in all groups (p < 0.05). The effect was maintained after 7 days only in the tongue scraping group (p < 0.05). In the intergroup analysis, no statistically significant differences were found among the groups (p > 0.05). For the microbiological analyses, no statistically significant differences were found in the groups/bacteria that were analyzed (p > 0.05). aPDT using a red LED and 0.005% methylene blue caused an immediate reduction in halitosis, but the effect was not maintained after 7, 14, or 30 days. No reduction occurred in the number of bacteria investigated or the quantification of universal 16S rRNA. ClinicalTrials.gov Identifier: NCT03656419.

Efficacy of antimicrobial photodynamic therapy (aPDT) for nonsurgical treatment of periodontal disease: a systematic review.

Although the standard treatment for periodontal disease is based on scaling and root planing (SRP), the use of antimicrobial photodynamic therapy (aPDT) has been studied as a complement to obtain better clinical results. The purpose of this study was to evaluate the effect of aPDT as adjuncts to SRP, compared with SRP alone, on clinical parameters of chronic periodontal patients. Only randomized controlled trials with at least 3-month follow-ups, of SRP alone and in association with aPDT, were included. The MEDLINE (PubMed), Google Scholar, and LILACS databases were searched for articles published up to July 2020. Random-effects meta-analyses were conducted for clinical attachment level (CAL) and probing pocket depth (PPD) change after treatment. Of 141 potentially relevant papers, 22 were included. The association between SRP and aPDT promoted a significant CAL gain and PPD reduction. Periodontal treatment was partially improved by aPDT, and a favorable effect of indocyanine green-mediated aPDT was observed, and high concentrations of phenothiazine chloride presented clinical improvement as well.

Effects of photobiomodulation in salivary glands of chronic kidney disease patients on hemodialysis.

This randomized placebo-controlled trial evaluates the impact of photobiomodulation (PBMT) on the salivary flow and biochemistry of patients with chronic kidney disease (CKD) on hemodialysis. Forty-four patients on hemodialysis self-responded two questionnaires for oral health and salivary gland function perception. The subjects were evaluated for function of salivary glands and randomly allocated to two groups: PBMT group (three irradiations at 808 nm, 100 mW, 142 J/cm2, and 4 J per site); and placebo group. Patients were submitted to non-stimulated and stimulated sialometry and after the treatment at baseline and 14 days. Salivary volume and biochemical of the saliva were analyzed. At baseline, most subjects had self-perception of poor oral health (52.6%) and salivary dysfunction (63.1%). Clinical exam revealed that 47.3% of subjects presented dry mucosa. PBMT promoted increase of the non-stimulated (p = 0.027) and stimulated saliva (p = 0.014) and decrease of urea levels in both non-stimulated (p = 0.0001) and stimulated saliva (p = 0.0001). No alteration was detected in total proteins and calcium analysis. Patients with kidney disease can present alteration in flow, concentrations, and composition of saliva, affecting oral health, but our findings suggest that PBMT is effective to improve hyposalivation and urea levels in saliva of patients with CKD.

Controlling methylene blue aggregation: a more efficient alternative to treat Candida albicans infections using photodynamic therapy.

Methylene Blue (MB) has been widely used in antimicrobial Photodynamic Therapy (aPDT), however, the mechanisms of action (Type I or Type II) are defined by its state of aggregation. In this sense, the identification of the relationships between aggregation, the mechanisms of action and the effectiveness against microorganisms, as well as the establishment of the means and the formulations that may favor the most effective mechanisms, are essential. Thus, the objective of this study was to assess the in vitro aPDT efficacies against Candida albicans, by using MB in vehicles which may influence the aggregation and present an oral formulation (OF) containing MB, to be used in clinical aPDT procedures. The efficacy of MB at 20 mg L-1 was tested in a range of vehicles (water, physiological solution - NaCl 0.9%, phosphate saline buffer - PBS, sodium dodecyl sulfate 0.25% - SDS and urea 1 mol L-1) in a C. albicans planktonic culture, when using 4.68 J cm-2 of 640 ± 12 nm LED for the irradiations, as well as 5 minutes of pre-irradiation time, together with measuring the UFC mL-1. Based upon these analyses, an OF containing MB in the most effective vehicle was tested in the biofilms, as a proposal for clinical applications. When comparing some of the vehicles, sodium dodecyl sulfate was the only one that enhanced an MB aPDT efficacy in a planktonic C. albicans culture. This OF was tested in the biofilms and 50 mg L-1 MB was necessary, in order to achieve some reduction in the cell viabilities after the various treatments. The light dosimetries still need further adaptations, in order for this formulation to be used in clinical applications. The present research has indicated that the development of this formulation for the control of MB aggregations may result in more effective clinical protocols.

Antimicrobial photodynamic therapy as a new approach for the treatment of vulvovaginal candidiasis: preliminary results.

In this work, we present the efficacy of photodynamic therapy against yeast cells in an animal model. We tested two photosensitizers, methylene blue and protoporphyrin IX. Thirty-seven female BALB-c mice with a body mass of 20-25 g were used. To achieve persistent vaginitis, estrus was induced by subcutaneous injection of 0.1 mg/mL estradiol valerate applied weekly. Three days after pseudo-estrus, intravaginal inoculation with Candida albicans was performed. Mice were anesthetized with ketamine (80 mg/kg) and xylazine (10 mg/kg) by intraperitoneal injection before inoculation, and antimicrobial photodynamic therapy (aPDT) was performed 5 days after fungal inoculation. Two photosensitizers were tested, methylene blue (MB; 100 µM) and protoporphyrin IX (PpNetNI; 10 µM). Two custom-made LEDs emitting light at 660 and 630 nm at approximately 800 mW each were used for irradiation. The aPDT treatment reduced the fungal colony-forming units (CFUs) by one order of magnitude for the MB (p = 0.020) and PpNetNI (p = 0.018) photosensitizers. Seven days after the treatment, there were significantly fewer CFUs compared to the control group (p = 0.041 and p = 0.035 for MB and PpNetNI, respectively), but this was not increased compared to the initial number immediately after aPDT. Using aPDT as a therapeutic option to decrease fungal infection in a vaginal candidiasis model resulted in a significant reduction in the C. albicans population. Both photosensitizers were effective for preventing reinfection within 7 days. The aPDT also had no effect on the vaginal mucosa at the ultrastructural level. In addition to the fungicide effect, we observed reduced swelling and lack of the formation of abscesses, microabscesses coating the cornified epithelial layer, and the accumulation of neutrophils in the submucosa.

Immediate results of photodynamic therapy for the treatment of halitosis in adolescents: a randomized, controlled, clinical trial.

UNLABELLED: Light with or without chemical agents has been used to induce therapeutic and antimicrobial effects. With photodynamic therapy, the antimicrobial effect is confined to areas covered by a photosensitive dye and irradiated with light. The aim of the present study was to evaluate the effect of photodynamic therapy for the treatment of halitosis in adolescents through the analysis of volatile sulfur compounds, especially sulfide. A controlled, clinical trial was conducted with 45 adolescents randomly allocated to three groups: group 1, photodynamic therapy administered to the dorsum of the tongue; group 2, treatment with a tongue scraper; and group 3, treatment with a tongue scraper combined with photodynamic therapy. The diagnosis of halitosis was performed using gas chromatography before and after treatment. Comparisons were made using the Kruskal-Wallis test followed by the Student-Newman-Keuls test, with the level of significance set at 5 % (p < 0.05). After treatment, a statistically significant reduction in halitosis was found in all groups (p < 0.001). The greatest reduction in total sulfides (median = 0) occurred with the combination of tongue scraper and photodynamic therapy. The present study describes a novel option for the treatment of halitosis in adolescents with an immediate effect that does not involve the mechanical aggression of the lingual papillae that occurs with conventional treatment. TRIAL REGISTRATION: Photodynamic Therapy in Adolescents Halitosis ( https://clinicaltrials.gov/ct2/show/NCT02007993?term=NCT02007993&rank=1 )Number: NCT02007993FUNDING:FAPESPNumber: 2013/13032-8.

Antimicrobial photodynamic inactivation inhibits Candida albicans virulence factors and reduces in vivo pathogenicity.

The objective of this study was to evaluate whether Candida albicans exhibits altered pathogenicity characteristics following sublethal antimicrobial photodynamic inactivation (APDI) and if such alterations are maintained in the daughter cells. C. albicans was exposed to sublethal APDI by using methylene blue (MB) as a photosensitizer (0.05 mM) combined with a GaAlAs diode laser (λ 660 nm, 75 mW/cm(2), 9 to 27 J/cm(2)). In vitro, we evaluated APDI effects on C. albicans growth, germ tube formation, sensitivity to oxidative and osmotic stress, cell wall integrity, and fluconazole susceptibility. In vivo, we evaluated C. albicans pathogenicity with a mouse model of systemic infection. Animal survival was evaluated daily. Sublethal MB-mediated APDI reduced the growth rate and the ability of C. albicans to form germ tubes compared to untreated cells (P < 0.05). Survival of mice systemically infected with C. albicans pretreated with APDI was significantly increased compared to mice infected with untreated yeast (P < 0.05). APDI increased C. albicans sensitivity to sodium dodecyl sulfate, caffeine, and hydrogen peroxide. The MIC for fluconazole for C. albicans was also reduced following sublethal MB-mediated APDI. However, none of those pathogenic parameters was altered in daughter cells of C. albicans submitted to APDI. These data suggest that APDI may inhibit virulence factors and reduce in vivo pathogenicity of C. albicans. The absence of alterations in daughter cells indicates that APDI effects are transitory. The MIC reduction for fluconazole following APDI suggests that this antifungal could be combined with APDI to treat C. albicans infections.

The influence of red laser irradiation timeline on burn healing in rats.

Low-level laser therapy (LLLT) promotes biomodulation of wound healing and literature reports that light delivery during the inflammation could play a different role compared with latter phases of the healing process. The objective of this study was to investigate whether single dose of a red laser (λ = 660 nm) is different from fractionated delivery protocol in full thickness burns. Two lesions were inflicted on the back of 36 rats. In the fractionated dose group (FG), the lesions were irradiated with 1 J/cm² on days 1, 3, 8, and 10 post-wounding. In the single dose group (SG), the lesions were irradiated with 4 J/cm² on day 1, immediately after injury. Control lesions (CG) received no light and were left to heal spontaneously. Blood flow was measured on days 1, 3, 8, 10, 15, and 21 using laser Doppler flowmetry. Animals were killed on days 3, 8, 10, 15, and 21. Skin specimens were obtained and routinely processed for hematoxylin and eosin. The specimens were evaluated according to differential leukocyte counting and angiogenesis. Statistical analysis was performed, and significance was accepted at p < 0.05. Irradiated groups showed a peak of new vessels on day 15 while, for CG, the peak was on day 21. On day 21, FG exhibited a significantly greater number of cumulative neutrophils while SG showed a higher number of mononuclear cells. Our results confirm that both protocols used accelerate angiogenesis and stimulate leukocyte chemotaxis on burn treatment. In addition, this work suggests that a single-dose LLLT accelerates the inflammatory phase of skin repair.

Antimicrobial photodynamic therapy mediated by methylene blue in surfactant vehicle as adjuvant to periodontal treatment. Randomized, controlled, double-blind clinical trial.

BACKGROUND: Antimicrobial photodymanic therapy mediated by methylene blue has been investigated as an adjunctive to periodontal treatment but the dimerization of photosensitizer molecules reduces the phototoxic effects. Sodium dodecyl sulfate is a surfactant that may control this aggregation. The aim of this study was evaluated the photodynamic effect of methylene blue in sodium dodecyl sulfate in periodontitis. METHODS: 36 participants with periodontitis were selected and allocated randomly in two group for intervention and other two for control - all of them were treated with scaling and root planing before aPDT. Three periodontal evaluations were done: at the selection time, at the day of intervention and thirty-day after this. Pre-irradiation time was 1 min and 2 min for irradiation. Laser (Therapy XT, DMC, São Carlos, Brazil) with wavelength of 660 nm and 100 mW of power was used. Two photosensitizer solutions with 100 µM methylene blue was used, one of them was in water and other in 0,25% of sodium dodecyl sulfate. Two sites of each participant were selected for the experimental procedures. Microbiological evaluations were performed to quantify microorganisms before and immediately after intervention. Quantitative microbiological evaluation was the primary outcome; morphological aspects of bacterial colony, and clinical probing depth was the secondary one. RESULTS: There was no significant difference between the groups in both bacterial reduction and the clinical parameter evaluated. CONCLUSION: The effect of methylene blue in surfactant did not cause enough phototoxic effects that could promote reduction of periodontal pocket depth.

Comparative study between photodynamic therapy and the use of probiotics in the reduction of halitosis in mouth breathing children: Study protocol for a randomized controlled clinical trial.

INTRODUCTION: Halitosis is a term that defines any odor or foul smell the emanates from the oral cavity, the origin of which may be local or systemic. One of the causes of local or oral halitosis is low salivary flow and dry mouth, which is also one of the complaints of individuals with the mouth-breathing habit. The aim of this study is to determine the effectiveness of antimicrobial photodynamic therapy (aPDT) and the use of probiotics for the treatment of halitosis in mouth-breathing children. METHODS: Fifty-two children between 7 and 12 years of age with a diagnosis of mouth breathing and halitosis determined through an interview and clinical examination will be selected. The participants will be divided into 4 groups: Group 1-treatment with brushing, dental floss and tongue scraper; Group 2-brushing, dental floss and aPDT applied to the dorsum and middle third of the tongue; Group 3-brushing, dental floss and probiotics; Group 4-brushing, dental floss, aPDT and probiotics. The use of a breath meter and microbiological analysis of the tongue coating will be performed before, immediately after treatment and 7 days after treatment. The quantitative analysis will involve counts of colony-forming bacteria per milliliter and real-time polymerase chain reaction. The normality of the data will be determined using the Shapiro-Wilk test. Parametric data will be submitted to analysis of variance and nonparametric data will be compared using the Kruskal-Wallis test. The results of each treatment in the different periods of the study will be compared using the Wilcoxon test. DISCUSSION: Due to the low level of evidence, studies are needed to determine whether treatment with aPDT using annatto as the photosensitizer and blue led as the light source is effective at diminishing halitosis in mouth-breathing children.

Evaluation of antimicrobial photodynamic therapy and minimal intervention associated with deproteinisation in permanent teeth with molar incisor hypomineralisation: study protocol for a clinical, controlled, blinded trial.

INTRODUCTION: Molar incisor hypomineralisation (MIH) is a qualitative defect of enamel development that occurs in the mineralisation phase. MIH affects one or more permanent molars and, occasionally, permanent incisors. The aim of the proposed study is to evaluate the clinical effect of antimicrobial photodynamic therapy (aPDT) on permanent teeth with MIH through decontamination and sensitivity control. METHODS AND ANALYSIS: Patients from 8 to 12 years of age with permanent molars will be randomly allocated to three groups. Group 1: selective chemical-mechanical removal of carious dentinal tissue around the walls of the cavity with Papacárie Duo and a curette followed by the application of aPDT and deproteinisation with Papacárie Duo; group 2: selective removal of carious dentinal tissue around the walls of the cavity with a curette, followed by the application of aPDT and deproteinisation with a 5% sodium hypochlorite solution; group 3: selective removal of carious dentinal tissue using a curette. The selected teeth must have a carious lesion in the dentin and posteruptive enamel breakdown on one or more surfaces with an indication for clinical restorative treatment. The teeth will subsequently be restored using a mixed technique with resin-modified glass ionomer cement and bulk-fill composite resin. The data will be submitted to descriptive statistical analysis. Associations with age and sex will be tested using either the χ2 test or Fisher's exact test. Pearson's correlation coefficients will be calculated to determine the strength of correlations between variables. Comparisons of the microbiological results (colony-forming units) will be performed using analysis of variance and the Kruskal-Wallis test. Kaplan-Meier survival analysis will be performed to assess the performance of the restorations. ETHICS AND DISSEMINATION: This protocol has been approved by the Human Research Ethics Committee of Nove de Julho University (certificate number: 61027522.0.0000.5511/approval date: 23 August 2022). The findings will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT05443035.

The importance of combining methods to assess Candida albicans biofilms following photodynamic inactivation.

BACKGROUND: Methylene blue (MB)-mediated photodynamic inactivation (PDI) has shown good results in killing Candida spp. Although MB solutions are commonly used, new formulations have been designed to improve PDI. However, chemical substances in the formulation may interfere with the PDI outcome. In this sense, different methodologies should be used to evaluate PDI in vitro. Herein, we report different methodologies to evaluate the effects of PDI with an oral formulation (OF) containing 0.005% MB on Candida albicans biofilm. METHODS: Biofilms were treated using the MB-OF, with 5 min pre-irradiation time and exposure to a 640 nm LED device (4.7 J/cm2). PDI was evaluated by the XTT reduction test, counting the colony forming units (CFU), a filamentation assay, crystal violet (CV) staining, and scanning electronic microscopy (SEM). RESULTS: PDI was able to reduce around 1.5 log10 CFU/mL, even though no significant differences were noted in metabolic activity in comparison to the control immediately after PDI. A significant decrease in yeast to hyphae transition was observed after PDI, while the biofilm exhibited flattened cells and a reduced number of yeasts in SEM. The CV assay showed increased biomass. CONCLUSION: MB-OF-mediated PDI was effective in C. albicans biofilms, as it significantly reduced the CFU/mL and the virulence of surviving cells. The CV data were inconclusive, since the OF components interacted with the CV, making the data useless. Taken together, our data suggest that the association of different methods allows complementary responses to assess how PDI mediated by a formulation impacts biofilms.

Combination efficacy of voriconazole and amphotericin B in the experimental disease in immunodeficient mice caused by fluconazole-resistant Cryptococcus neoformans.

The therapeutic efficacy of amphotericin B and voriconazole alone and in combination with one another were evaluated in immunodeficient mice (BALB/c-SCID) infected with a fluconazole-resistant strain of Cryptococcus neoformans var. grubii. The animals were infected intravenously with 3 × 10(5) cells and intraperitoneally treated with amphotericin B (1.5 mg/kg/day) in combination with voriconazole (40 mg/kg/days). Treatment began 1 day after inoculation and continued for 7 and 15 days post-inoculation. The treatments were evaluated by survival curves and yeast quantification (CFUs) in brain and lung tissues. Treatments for 15 days significantly promoted the survival of the animals compared to the control groups. Our results indicated that amphotericin B was effective in assuring longest-term survival of infected animals, but these animals still harbored the highest CFU of C. neoformans in lungs and brain at the end of the experiment. Voriconazole was not as effective alone, but in combination with amphotericin B, it prolonged survival for the second-longest time period and provided the lowest colonization of target organs by the fungus. None of the treatments were effective in complete eradication of the fungus in mice lungs and brain at the end of the experiment.

Erythrosine as a photosensitizer for antimicrobial photodynamic therapy with blue light-emitting diodes - An in vitro study.

BACKGROUND: This study aims to test the absorbance of a new composition of erythrosine, its pH, cell viability and potential as a photo sensitizer against Candida albicans when irratiaded with blue light emitting-diode (LED). METHODS: For pH and absorbance tests, erythrosine was prepared at a concentration of 0.03/ml. The cells of the L929 strain were cultured and the alamarBlue® assay was performed on samples to assess cell viability. For the microbiological essay, the strain of Candida albicans ATCC 90028 was selected. Yeast suspensions were divided into the following groups: control without irradiation or photosensitizer (C), irradiated group without photosensitizer (L), photosensitizer group without irradiation (0), and groups that received photosensitizer and irradiation, called aPDT groups. RESULTS: Erythrosine had no significant changes in pH and its absorbance was also consistent (≅400 nm). When it came to cell viability, on the first day, the group that was in contact with the dye and irradiated with the LED in minimun power was found to have the higher cell proliferation. On day 3, both irradiated groups (maximum and minimum) showed the highest cell proliferation. In the microbiological essay with C. albicans, aPDT groups started to show microbial reduction after 60 and 90 s of irradiation and when irradiated for 120 s, 6 microbial reduction logs were found. CONCLUSIONS: The erythrosine in question is a PS, with pH stability, blue light absorbance, cell viability and efficacy against C. albicans. More studies with this PS should be encouraged in order to verify its performance in aPDT.

Comparative study between photodynamic therapy with urucum + Led and probiotics in halitosis reduction-protocol for a controlled clinical trial.

BACKGROUND: Halitosis is a term that defines any foul odor emanating from the oral cavity. The origin may be local or systemic. The aim of the proposed protocol is to determine whether treatment with antimicrobial photodynamic therapy (aPDT) and treatment with probiotics are effective at eliminating halitosis. MATERIALS AND METHODS: Eighty-eight patients, from 18 to 25 years old with a diagnosis of halitosis (H2S≥112 ppb, determined by gas chromatography) will be randomly allocated to four groups (n = 22) that will receive different treatments: Group 1 -treatment with teeth brushing, dental floss and tongue scraper; Group 2 -brushing, dental floss and aPDT; Group 3 -brushing, dental floss and probiotics; Group 4 -brushing, flossing, aPDT and probiotics. The results of the halimetry will be compared before, immediately after, seven days and thirty days after treatment. The microbiological analysis of the coated tongue will be performed at these same times. The normality of the data will be determined using the Shapiro-Wilk test. Data with normal distribution will be analyzed using analysis of variance (ANOVA). Non-parametric data will be analyzed using the Kruskal-Wallis test. The Wilcoxon test will be used to analyze the results of each treatment at the different evaluation periods. CLINICAL TRAIL REGISTRATION: NCT03996044.

Photodynamic therapy for endodontic treatment of primary teeth: A randomized controlled clinical trial.

OBJECTIVES: This study aimed to evaluate the reduction in bacterial load following conventional endodontic treatment with and without antimicrobial photodynamic therapy (a-PDT) in primary teeth. METHODS: Thirty primary anterior teeth with a diagnosis of pulp necrosis were selected. Patients were randomly allocated to two groups as follows: Group I, patients undergoing conventional root canal therapy (n = 15) and Group II, patients undergoing conventional root canal therapy combined with antimicrobial PDT (n = 15). For PDT, methylene blue, at a concentration of 0.005 %, was used as the photosensitizing agent, which was applied to the interior of the canal with a sterile paper cone for 3 min, followed by the administration of laser light for 40 s (wavelength: 660 nm, energy density: 4 J/cm², power: 100 mW), delivered in direct contact at the entrance to the root canal. Two microbiological samples of the intra-canal content were taken (one before and one immediately after treatment in both groups) using paper cones. Clinical follow-up involved the investigation of fistulas and mobility and was performed 1- and 3 months after treatment. Data were statistically analyzed. RESULTS: The reduction in bacterial load was 93 % in Group I and 99 % in Group II, with no statistically significant difference. CONCLUSIONS: Conventional treatment combined with antimicrobial PDT with parameters used in this study proved effective but presented equal efficacious capability to conventional endodontic treatment alone. CLINICAL SIGNIFICANCE: The use of PDT has been studied in endodontic treatment protocols in permanent teeth. However, clinical trials in deciduous teeth are necessary for establishing the effectiveness and parameters of this application. The present study analyzes the results of PDT in the endodontic treatment of deciduous teeth.