Avaliação dos efeitos da terapia fotodinâmica com hipericina-glucamina no tratamento da doen ça periodontal induzida em ratos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo comparativo do efeito da terapia fotodinâmica e uso de antibióticos em lesões podais (Bumblefoot) em pinguins de Magalhães (Spheniscus magellanicus)

Pós-graduação em Biotecnologia Animal - FMVZ

Efeito sinérgico entre a terapia fotodinâmica e a cisplatina: uma nova abordagem para o câncer de colo uterino

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da aPDT na osseointegração de implantes em alvéolos contaminados

Objective: The aim of this study is to evaluate by histometric and immunohistochemistry analysis the effects of antimicrobial photodynamic therapy (aPDT) in alveolar prior to placement of mini-implants in animals with or without induced periodontal disease. Material and method: Thirty-two rats were used. Periodontal disease (PD) was induced by ligature in the lower left first molar. After 7 days of PD evolution, it was performed removal of the ligature and extraction of the left lower first molars in all animals. Thus, animals were divided into 2 groups (n=16) according to the treatments in the dental alveolus before immediate implant installation: MD (control) : mechanical debridement (MD), irrigation with 1 ml of saline solution followed by implant installation; aPDT- MD, irrigation with 1 ml of Toluidine Blue-O and low intensity laser (LLLT) and implant installation. Eight animals from each group were euthanized at 15 and 30 days after the installation of mini-implants. Specimens were processed for histologic, immunohistochemical and histometric analysis. The histometric data were processed for statistical analysis (Kruskall-Wallis and Dunn test; p <0.05). Result: In treatment analysis, results indicated that there was a greater BIC in implants installed in uncontaminated alveolus treated with a PDT ( p<0,05) and greater imuno-reactivity to OPG in bone issue treated with aPDT. Conclusion: The aPDT proved to be effective in bone loss control in no contaminated area and it has increased the bone loss and metabolic activity in alveolus irradiated prior to implant installation.

Comparative effects of photodynamic therapy mediated by curcumin on standard and clinical isolate of Streptococcus mutans

Aim: The aim of this study was investigate the effect of photodynamic therapy (PDT) using curcumin (C) as a photosensitizing agent irradiated with an LED (L) in the blue wavelength as a light source on a standard and clinical isolate of Streptococcus mutans (S. mutans) in a planktonic suspension model. Materials and methods: Suspensions of both strains were divided into 4 groups as follows: absence of C and L (control group: C–L–), with C and without L (C group: C+L–), absence of C with L (L group: C–L+) and presence of C and L (PDT group: C+L+). Three different concentrations of curcumin (0.75 mg/ml, 1.5 mg/ml and 3 mg/ml) and three light fluences of studied light source (24, 48 and 72 J cm–2) were tested. Aliquots of each studied group was plated in BHI agar and submitted to colony forming units counting (CFU/ml) and the data transformed into logarithmical scale. Results: A high photoinactivation rate of more than 70% was verified to standard S. mutans strain submitted to PDT whereas the clinical isolate showed a lower sensitivity to all the associations of curcumin and LED. A slight bacterial reduction was verified to C+L– and C–L+, demonstrating no toxic effects to the isolated application of light and photosensitizer to both S. mutans strains tested. Conclusion: Photodynamic therapy using a combination of curcumin and blue LED presented a substantial antimicrobial effect on S. mutans standard strain in a planktonic suspension model with a less pronounced effect on its clinical isolate counterparts due to resistance to this alternative approach. Clinical significance: Alternative antimicrobial approaches, as photodynamic therapy, should be encouraged due to optimal results against cariogenic bacteria aiming to prevent or treat dental caries.

Genotoxic effect of photodynamic therapy mediated by curcumin on Candida albicans

Photodynamic therapy (PDT) is a promising method for localized and specific inactivation of fungi and bacteria. A nontoxic light-sensitive compound is taken up by cells, which are then exposed selectively to light, which activates toxicity of the compound. We investigated the potential of sublethal PDT using light-sensitive curcumin (CUR) in combination with blue (455 nm) light to promote reactive oxygen species (ROS) formation in the form of singlet oxygen and DNA damage of Candida albicans. Surprisingly, CUR-mediated PDT but also light alone caused significantly longer comet tails, an indication of DNA damage of C. albicans when compared with the negative control. The intracellular ROS production was also significantly higher for the group treated only with light. However, PDT compared to blue light alone significantly slowed DNA repair. Comet tails decreased during 30 min visualized as a 90% reduction in length in the absence of light for cells treated with light alone, while comet tails of cells treated with PDT only diminished in size about 45%. These results indicate that complex mechanisms may result in PDT in a way that should be considered when choosing the photosensitive compound and other aspects of the treatment design.

Photodynamic therapy in root canals contaminated with Enterococcus faecalis using curcumin as photosensitizer

The aim of the study was to evaluate the photodynamic therapy (PDT) effect on root canals contaminated with Enterococcus faecalis using a light emitting diode (LED) light and a curcumin solution (CUR) as photosensitizer (PS). Eighty root canals from uniradicular human teeth were prepared with Protaper Universal rotary system and contaminated with E. faecalis for 21 days. They were divided as: GIa-PDT (CUR, pre-irradiation for 5 + 5 min of irradiation); GIb-PDT (CUR, pre-irradiation for 5 + 10 min of irradiation); GIIa-(CUR, pre-irradiation for 5 + 5 min without irradiation); GIIb-(CUR pre-irradiation for 5 + 10 min of irradiation); GIIIa-(physiological solution and irradiation for 5 min); and GIIIb-(physiological solution and irradiation for 10 min); positive and negative control groups. Collections from root canals were made at time intervals of 21 days after contamination, immediately after treatment, and 7 days after treatment, and submitted to colony forming units per milliter (CFU mL-1) counts. The data were submitted to ANOVA and Tukey multiple comparison tests, at a level of significance of 5 %. In the immediate post-treatment collection, group GIa showed greater bacterial reduction in comparison with GIIa, GIIb, GIIIa, GIIIb, and positive control (P < 0.05). At 7 days post-treatment, GIa showed significant bacterial reduction only in comparison with GIIIa (P < 0.05). Curcumin as sensitizer was effective by 5 min LED irradiation but not by 10 min irradiation PDT using LED light, and curcumin as PS was not effective in eliminating E. faecalis. No difference was observed for periods of irradiation.

Eficiência da terapia fotodinâmica em Staphylococcus aureus e Escherichia coli

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Prevalência, Virulência e sensibilidade às terapias antimicrobianas das cepas de enterecoccus faecalis e enterococcus faecium isoladas de infecções endodônticas

Pós-graduação em Biopatologia Bucal - ICT

Efeito antimicrobiano de múltiplas sessões de tereapia fotodinâmica sobre biofilmes de Candida spp. formados in vitro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparative study between photodynamic and antibiotic therapies for treatment of footpad dermatitis (bumblefoot) in Magellanic penguins (Spheniscus magellanicus)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Synergistic effect of photodynamic therapy and cisplatin: a novel approach for cervical cancer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Assessment of ALA-induced PpIX production in porcine skin pretreated with microneedles

Photodynamic therapy (PDT) is used for skin treatments of premalignant and cancer lesions and recognized as a non-invasive technique that combines tissue photosensitization and subsequent exposure to light to induce cell death. However, it is limited to the treatment of superficial lesions, mainly due to the low cream penetration. Therefore, the improvement of transdermal distribution of aminolevulinic acid (ALA) is needed. In this study, the kinetics and homogeneity of production of ALA-induced PpIX after the skin pre-treatment with microneedles rollers of 0.5, 1.0 and 1.5 mm length were investigated. An improvement in homogeneity and production of PpIX was shown in a porcine model. Widefield fluorescence imaging three hours after the topical application of ALA-cream in the combined treatment with microeedles rollers.

Efeito de diferentes terapias locais para o tratamento de periodontite crônica em indivíduos diabéticos tipo 2: estudo clínico controlado randomizado triplo cego de boca dividida com acompanhamento de seis meses

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Radiographic assessment of potodynamic therapy as an adjunctive treatment on induced periodontitis in immunosupressed rats

OBJECTIVE: The aim of this study was to assess radiographically the effect of photodynamic therapy (PDT) as an adjunctive treatment to scaling and root planing (SRP) on induced periodontitis in dexamethasone-induced immunosuppressed rats. MATERIAL AND METHODS: The animals were divided into 2 groups: ND group (n=60): saline treatment; D group (n=60): dexamethasone treatment. In both ND and D groups, periodontal disease was induced by the placement of a ligature in the left first mandibular molar. After 7 days, ligature was removed and all animals received SRP, being divided according to the following treatments: SRP: saline and PDT: phenothiazinium dye (TBO) plus laser irradiation. Ten animals per treatment were killed at 7, 15 and 30 days. The distance between the cementoenamel junction and the height of the alveolar bone crest in the mesial surface of the mandibular left first molars was determined in millimeters in each radiograph. he radiographic values were analyzed statistically by ANOVA and Tukey's test at a p value <0.05. RESULTS: Intragroup radiographic assessment (ND and D groups) showed that there was statistically signifcant less bone loss in the animals treated with PDT in all experimental periods compared to those submitted to SRP. Intergroup radiographic analysis (ND and D groups) demonstrated that there was greater bone loss in the ND group treated with SRP compared to the D group treated with PDT at 7 and 30 days. CONCLUSION: PDT was an effective adjunctive treatment to SRP on induced periodontitis in dexamethasone-induced immunosuppressed rats.