http://bibliotecatede.uninove.br/handle/tede/31 2026-11-11T01:13:38Z http://bibliotecatede.uninove.br/handle/tede/4051 Título: Terapia fotodinâmica antimicrobiana com butil azul de toluidina O (BuTBO) para inativação de biofilme de Aggregatibacter actinomycetemcomitans em dentes bovinos Autor: Tortamano, Ana Carolina Alves Camargo Primeiro orientador: Prates, Renato Araujo Abstract: As an adjunct intervention to mechanical periodontal treatment, antimicrobial photodynamic therapy (aPDT) aims to induce the production of reactive oxygen species, thereby reducing microbial infection. Butyl toluidine blue O, a photosensitizer recently developed from the phenothiazine family, presents physical-chemical modifications to the structure of toluidine blue O, resulting in decreased aggregation and increased singlet oxygen production. The objective of this study was to investigate the efficacy of butyl toluidine blue O in eliminating Aggregatibacter actinomycetemcomitans, using a pre-irradiation time of 1 minute. To achieve this, a biofilm was cultured on bovine dental samples, followed by the application of aPDT. Microbiological evaluations and scanning electron microscopy analyses were performed. The experiment was structured into a group called BuTBO, which was subdivided into six subgroups: control group, laser group, photosensitizer group (corresponding to a pre-irradiation time of 1 minute), and PDT groups with different irradiation times (1, 3, and 5 minutes). A laser with a wavelength of 660 nm and an irradiance of 250 mW/cm² was used, generating energies of 6, 18, and 30 J for exposure times of 60, 180, and 300 seconds, respectively, and radiant exposures of 15, 45, and 75 J/cm². After the procedures, the samples were cultured under microaerophilic conditions, counted, and converted into colony-forming units per milliliter (CFU/mL) for comparative analysis. The results indicated that the application of BuTBO with pre-irradiation time and irradiation time of 1 minute did not show a statistically significant difference (p > 0.05). However, with irradiation times of 3 and 5 minutes, a statistically significant difference was observed (p < 0.01). Irradiation for 5 minutes resulted in a 99.99% microbial reduction in the biofilm. We conclude that BuTBO shows potential as a photosensitizer for reducing A. actinomycetemcomitans microbial loads. Instituição: Universidade Nove de Julho Tipo do documento: Tese 2024-10-29T00:00:00Z http://bibliotecatede.uninove.br/handle/tede/4050 Título: Desenvolvimento de formulação contendo azul de metileno associado a polímero para terapia fotodinâmica antimicrobiana odontológica Autor: Monteiro, Carolina Montovam Primeiro orientador: Pavani, Christiane Abstract: Methylene blue (AM) is a cationic phenothiazine compound with interesting properties for application in antimicrobial photodynamic therapy (aPDT). Its aggregation characteristic directs the photochemical action mechanisms and can be favored depending on the medium in which it is transmitted. Additionally, difficulties in maintaining a solution in specific locations in the oral cavity during the pre-irradiation period motivated the development of a formulation with higher viscosity in order to increase the residence time in the location and preserve the photochemical properties of AM. The objective of this research was to develop AM formulation for aPDT associated with mucoadhesive biopolymers of different ionic characters: hydroxypropylmethylcellulose and carboxymethylcellulose (CMC), as well as the anionic surfactant sodium dodecyl sulfate (SDS). The AM aggregation state was evaluated by spectrophotometric determination of the dimer/monomer (D/M) ratio. The viscosity and density of the formulations, the influence of pH and three AM concentrations on the D/M ratio were analyzed. In vitro microbiological tests were conducted on Candida albicans (ATCC 10231) biofilm. In the incorporation experiment, the samples were treated with AM conveyed in water or in a formulation and the pre-incubation time evaluated was 5, 10, 30 and 60 min. Viability was evaluated in water at acidic pH, formula, AM at 0.005% and 0.010%, in water and in formula. After 5 min in the dark, the biofilm was washed and irradiated for 27 or 54 min. Dilutions were incubated and colony forming units per mL (CFU/mL) were counted. The selected formulation had its stability evaluated for one year through organoleptic tests, pH, AM monomer quantification and D/M ratio. Results indicate a lower D/M ratio with increasing concentration of polymers without SDS, however, with the addition of surfactant, there is an even greater reduction in D/M for the two polymers studied, with less aggregation of AM observed in the acidic formulation with CMC and SDS. Lower AM concentrations favor less aggregation, with no statistical difference between 0.002% and 0.005%. AM conveyed in water presents greater incorporation than in formula. Viability in 24h biofilm resulted in a significant reduction only for the formulation containing 0.005% AM. In a 48-hour biofilm, all AM samples, in water or formula, showed a significant reduction, with two successive 27-min irradiations with double treatment being more effective than the single 54-min irradiation, reaching a maximum average reduction of 4.26 Log for the 0.005% AM formula, demonstrating that the lower incorporation did not affect the antimicrobial action for this sample. The optimized formulation remained stable for 1 year in terms of organoleptic characteristics, pH and AM quantification. Between 6 and 12 months, the D/M ratio showed a statistical difference, although it may not be relevant since the values obtained were very close. Therefore, the association of pharmacotechnical adjuvants, the ionic charge of the polymer, the AM concentration and the pH of the medium in which it is conveyed influence its aggregation behavior, making it safe to use the optimized formulation developed for 12 months after manufacturing and effective for aPDT according to in vitro viability assessments in C. albicans biofilm with a pre-irradiation time of 5 min and 2 successive irradiations according to established parameters, without compromising antimicrobial effectiveness and with the advantage of favoring greater retention at the applied site. Additional studies can be carried out, aiming to optimize dosimetry in order to achieve better performance for clinical aPDT. Instituição: Universidade Nove de Julho Tipo do documento: Tese 2024-06-10T00:00:00Z http://bibliotecatede.uninove.br/handle/tede/4049 Título: Efeito da terapia fotodinâmica antimicrobiana mediada por butil azul de toluidina O (BuTBO) em candida albicans Autor: Magalhães, Fabiana Divina Primeiro orientador: Prates, Renato Araujo Abstract: Candida albicans is one of the most common fungal infections in humans, acting both as part of the normal microbiota and as an opportunistic pathogen. It colonizes sites such as the skin, mouth, gastrointestinal tract, and vagina. In healthy individuals, it is detected in saliva and oral mucosa in approximately 40% of cases and is associated with periodontal disease. Moreover, infection by C. albicans can trigger Th17-mediated inflammation, highlighting the need for effective and long-lasting treatments. Antimicrobial Photodynamic Therapy (aPDT) is a promising approach that uses photosensitizers activated by light to inhibit or kill microorganisms. This study investigated the antimicrobial effect of aPDT mediated by Toluidine Blue O Butyl (BuTBO) on C. albicans. Using the C. albicans ATCC 90028 strain, yeast cells were cultured on Sabouraud Dextrose Agar, and the efficacy of BuTBO was evaluated in comparison with control groups. The results demonstrated that irradiation without a photosensitizer was not effective against C. albicans (p > 0.05). From 2 minutes of irradiation onward, a reduction in microbial load was observed, with a large number of cells inactivated after 2 minutes. Fluorescence microscopy revealed that BuTBO predominantly localized inside the yeast cells, with the photosensitizer accumulating intracellularly at an order of 1012 molecules per cell. The data suggest that irradiation time is a critical factor for the activation of the photosensitizer and the generation of reactive oxygen species (ROS), which are essential for cellular inactivation. aPDT with BuTBO demonstrated high efficacy against C. albicans, starting the death of the fungus after 2 min of irradiation. The combination of the photosensitizer with light is crucial for ROS production, which drives the antimicrobial effect. Longer irradiation times (3 and 5 minutes) were found to be key determinants of treatment success. BuTBO accumulates within fungal cells and generates ROS without disrupting cellular structure, making it a promising candidate for controlling fungal infections. Instituição: Universidade Nove de Julho Tipo do documento: Tese 2024-12-09T00:00:00Z http://bibliotecatede.uninove.br/handle/tede/4048 Título: Efeito da terapia fotodinâmica com urucum e led e probióticos na redução da halitose: ensaio clínico controlado randomizado Autor: Motta, Pamella de Barros Primeiro orientador: Bussadori, Sandra Kalil Abstract: Halitosis is a term that defines any odor or bad smell originating from the oral cavity, which may have local or systemic origin. This project aims to verify whether treatment with antimicrobial photodynamic therapy (aPDT) and treatment with probiotics are effective in eliminating it. 52 patients were selected, aged 18 to 25 years, diagnosed with halitosis, presenting sulfide (SH2) ≥ 112 ppb on gas chromatography. Participants were randomly divided into 4 groups (n=13), which received different treatments: Group 1: treatment with brushing, dental floss (all participants were instructed through a lecture to brush with a toothpaste containing amine fluoride in its composition (Elmex®) and use of dental floss, 3 times a day after meals for 30 days and tongue scraper; Group 2: brushing, dental floss and aPDT with annatto and blue LED, applied to the back and middle third of the tongue ; Group 3: brushing, dental floss and probiotics (capsules manufactured in a pharmacy containing strains of Lactobacillus salivarius WB21 (6.7 x 108 CFU) and xylitol (280mg). 42 capsules were given to each patient, who ingested 1 capsule, 3 times a day after meals, for 14 days; Group 4: brushing, flossing, aPDT and probiotics. Clinical results showed an immediate reduction in halitosis with aPDT, with the use of the scraper and with the use of both therapies combined. The immediate results show the effectiveness of the treatments, for a period shorter than 7 days, which has yet to be discovered. The use of probiotics showed no difference in sulfide levels compared to initial levels. As for the microbiological results, when the tongue coating samples were analyzed by quantitative PCR for Porphyromonas gingivalis, Tannerella forsythia, Tannerella forsythia, it was not possible to observe a difference (p<0.05) between the groups for any of the bacteria evaluated. As for the microbiome, a representative sample was analyzed. There was no difference in alpha diversity between the samples studied by Chao1, Shannon and Simpson analysis. Regarding the analysis of relative abundance regarding the genera found, a difference was observed only in the genus Pseudarthrobacter (p<0.05) between G2 and G3 at 14 days. In relation to other groups and times, there was no difference (p<0.05) regarding relative abundance for species and genus. Therefore, taking into account the limitations of this study, it can be concluded that treatment with aPDT or probiotics were not able to alter the microbiota in the tongue coating of patients with halitosis under these experimental conditions. Instituição: Universidade Nove de Julho Tipo do documento: Tese 2024-09-18T00:00:00Z