O tratamento da Periodontite Agressiva (PA) representa um desafio para os clínicos, pois não existem protocolos padronizados para um controle eficiente da doença. Este estudo clínico controlado, aleatório e duplo-cego avaliou o efeito de múltiplas aplicações da Terapia Fotodinâmica antimicrobiana (TFDa) como adjuvante ao tratamento periodontal não cirúrgico (TPnc) em pacientes diagnosticados com PA. Utilizando um modelo de estudo do tipo boca dividida, 20 pacientes com diagnóstico clínico de PA foram tratados com TFDa (Grupo Teste) associada à raspagem e alisamento radicular (RAR) ou apenas RAR (Grupo Controle). As aplicações da TFDa foram realizadas em 4 episódios (dias 0, 2, 7 e 14). Todos os pacientes foram acompanhados por 90 dias. Os seguintes parâmetros clínicos, microbiológicos e imunológicos foram analisados: i) profundidade de bolsa à sondagem (PS) e nível de inserção clínico (NCI); ii) contagem de 40 espécies subgengivais em amostras de placa bacteriana (checkerboard DNA-DNA hybridization); iii) avaliação dos níveis de Interleucina (IL)-1&beta;, IL-10 e Fator de Necrose Tumoral alfa (TNF-&alpha;) no fluido crevicular gengival (Luminex). Os dados obtidos foram estatisticamente analisados. Na análise de bolsas periodontais profundas (PS inicial &ge; 7mm), o Grupo Teste apresentou, aos 90 dias, redução de PS (-3,96 mm ± 0,83) e ganho de inserção clínica (2,77 mm ± 1,05) significativamente maiores (p < 0,05) que aqueles do Grupo Controle (PS = - 2,56 ± 0,72; NCI = 1,75 ± 1,07). Foi constatado, também, um número significativamente menor de bolsas periodontais residuais (PS &ge; 5mm) no Grupo Teste quando comparado ao Grupo Controle aos 90 dias (p < 0,05). Na análise microbiológica, o Grupo Teste apresentou proporções significativamente menores de espécies microbianas dos complexos vermelho e laranja, bem como maiores proporções de espécies do complexo azul quando comparado ao Grupo Controle aos 90 dias (p < 0,05). Na análise imunológica, observou-se níveis de IL-1&beta; no Grupo Controle significativamente maiores que aqueles do Grupo Teste aos 14, 30 e 90 dias (p < 0,05). Em relação aos níveis de IL-10, apenas o Grupo Teste apresentou valores significativamente maiores (p < 0,05) que aqueles do baseline aos 30 dias. Para TNF-&alpha;, não foi possível observar diferenças significativas nas comparações inter e intragrupos em todos os períodos experimentais. O Grupo Teste apresentou razão IL-1&beta;/IL-10 significativamente menor que aquela do Grupo Controle aos 90 dias (p < 0,05). Pode-se concluir que a utilização de aplicações múltiplas da TFDa como recurso adjuvante à TPnc de pacientes com PA: i) melhora significativamente os parâmetros clínicos periodontais, reduzindo a necessidade de tratamentos periodontais adicionais aos 90 dias; ii) elimina de forma mais eficaz periodontopatógenos dos complexos vermelho e laranja; iii) melhora os parâmetros imunoinflamatórios, reduzindo a concentração de citocinas proinflamatórias e aumentando os níveis de citocinas anti-inflamatórias. / Treatment of Aggressive Periodontitis (AP) is challenging for clinicians because there are no standardized protocols for effective disease control. This double-blind randomized controlled clinical trial evaluated the effects of multiple applications of antimicrobial Photodynamic Therapy (aPDT) as an adjunct to scaling and root planning (SRP) on patients diagnosed with AP. Using a split-mouth model, 20 patients with clinical diagnosis of AP were treated with aPDT associated with SRP (Test Group) or SRP alone (Control Group). aPDT applications were performed along with SRP and 2, 7 and 14 days after SRP. All patients were monitored during 90 days. The following clinical, microbiological and immunological parameters were analyzed: i) probing pocket depth (PPD) and clinical attachment level (CAL), ii) counts of 40 subgingival species in plaque samples (checkerboard DNA-DNA hybridization) and iii) levels of interleukin (IL)-1&beta;, IL-10 and tumor necrosis factor (TNF)-&alpha; in gingival crevicular fluid (Luminex). Data were statistically analyzed. In deep periodontal pockets (initial PPD &ge; 7 mm), the Test Group presented a decrease in PPD (-3.96 ± 0.83 mm) and a clinical attachment gain (2.77 ± 1.05 mm) significantly higher than the Control Group (PPD = - 2.56 ± 0.72 mm; CAL = 1.75 ± 1.07 mm) at 90 days (p < 0.05). It was also observed significantly fewer residual periodontal pockets (PPD &ge; 5 mm) in the Test Group when compared to the Control Group at 90 days (p < 0.05). Regarding microbiological analysis, the Test Group presented proportions of red and orange complexes significantly lower and proportions of blue complex significantly higher than the Control Group at 90 days (p < 0.05). Immunological analysis demonstrated significantly lower levels of IL-1&beta; in the Control Group when compared to the Test Group at 14, 30 and 90 days (p < 0.05). Only the Test Group presented significantly higher IL-10 levels in relation to baseline values at 30 days (p < 0.05). Intra and inter-groups comparisons of the mean levels of TNF-&alpha; did not demonstrate significantly differences. IL-1&beta;/IL-10 ratio was significantly lower in the Test Group than in the Control Group at 90 days (p < 0.05). It can be concluded that repeated aPDT as an adjunct to SRP in the nonsurgical treatment of AP: i) significantly improves clinical periodontal parameters, reducing the need for further treatments at 90 days; ii) eliminates periodontal pathogens of red and orange complexes more effectively and iii) enhances the host immunoinflammatory response, decreasing the levels of proinflammatory cytokines and increasing the levels of anti-inflammatory cytokines.

O tratamento da Periodontite Agressiva (PA) representa um desafio para os clínicos, pois não existem protocolos padronizados para um controle eficiente da doença. Este estudo clínico controlado, aleatório e duplo-cego avaliou o efeito de múltiplas aplicações da Terapia Fotodinâmica antimicrobiana (TFDa) como adjuvante ao tratamento periodontal não cirúrgico (TPnc) em pacientes diagnosticados com PA. Utilizando um modelo de estudo do tipo boca dividida, 20 pacientes com diagnóstico clínico de PA foram tratados com TFDa (Grupo Teste) associada à raspagem e alisamento radicular (RAR) ou apenas RAR (Grupo Controle). As aplicações da TFDa foram realizadas em 4 episódios (dias 0, 2, 7 e 14). Todos os pacientes foram acompanhados por 90 dias. Os seguintes parâmetros clínicos, microbiológicos e imunológicos foram analisados: i) profundidade de bolsa à sondagem (PS) e nível de inserção clínico (NCI); ii) contagem de 40 espécies subgengivais em amostras de placa bacteriana (checkerboard DNA-DNA hybridization); iii) avaliação dos níveis de Interleucina (IL)-1&beta;, IL-10 e Fator de Necrose Tumoral alfa (TNF-&alpha;) no fluido crevicular gengival (Luminex). Os dados obtidos foram estatisticamente analisados. Na análise de bolsas periodontais profundas (PS inicial &ge; 7mm), o Grupo Teste apresentou, aos 90 dias, redução de PS (-3,96 mm ± 0,83) e ganho de inserção clínica (2,77 mm ± 1,05) significativamente maiores (p < 0,05) que aqueles do Grupo Controle (PS = - 2,56 ± 0,72; NCI = 1,75 ± 1,07). Foi constatado, também, um número significativamente menor de bolsas periodontais residuais (PS &ge; 5mm) no Grupo Teste quando comparado ao Grupo Controle aos 90 dias (p < 0,05). Na análise microbiológica, o Grupo Teste apresentou proporções significativamente menores de espécies microbianas dos complexos vermelho e laranja, bem como maiores proporções de espécies do complexo azul quando comparado ao Grupo Controle aos 90 dias (p < 0,05). Na análise imunológica, observou-se níveis de IL-1&beta; no Grupo Controle significativamente maiores que aqueles do Grupo Teste aos 14, 30 e 90 dias (p < 0,05). Em relação aos níveis de IL-10, apenas o Grupo Teste apresentou valores significativamente maiores (p < 0,05) que aqueles do baseline aos 30 dias. Para TNF-&alpha;, não foi possível observar diferenças significativas nas comparações inter e intragrupos em todos os períodos experimentais. O Grupo Teste apresentou razão IL-1&beta;/IL-10 significativamente menor que aquela do Grupo Controle aos 90 dias (p < 0,05). Pode-se concluir que a utilização de aplicações múltiplas da TFDa como recurso adjuvante à TPnc de pacientes com PA: i) melhora significativamente os parâmetros clínicos periodontais, reduzindo a necessidade de tratamentos periodontais adicionais aos 90 dias; ii) elimina de forma mais eficaz periodontopatógenos dos complexos vermelho e laranja; iii) melhora os parâmetros imunoinflamatórios, reduzindo a concentração de citocinas proinflamatórias e aumentando os níveis de citocinas anti-inflamatórias. / Treatment of Aggressive Periodontitis (AP) is challenging for clinicians because there are no standardized protocols for effective disease control. This double-blind randomized controlled clinical trial evaluated the effects of multiple applications of antimicrobial Photodynamic Therapy (aPDT) as an adjunct to scaling and root planning (SRP) on patients diagnosed with AP. Using a split-mouth model, 20 patients with clinical diagnosis of AP were treated with aPDT associated with SRP (Test Group) or SRP alone (Control Group). aPDT applications were performed along with SRP and 2, 7 and 14 days after SRP. All patients were monitored during 90 days. The following clinical, microbiological and immunological parameters were analyzed: i) probing pocket depth (PPD) and clinical attachment level (CAL), ii) counts of 40 subgingival species in plaque samples (checkerboard DNA-DNA hybridization) and iii) levels of interleukin (IL)-1&beta;, IL-10 and tumor necrosis factor (TNF)-&alpha; in gingival crevicular fluid (Luminex). Data were statistically analyzed. In deep periodontal pockets (initial PPD &ge; 7 mm), the Test Group presented a decrease in PPD (-3.96 ± 0.83 mm) and a clinical attachment gain (2.77 ± 1.05 mm) significantly higher than the Control Group (PPD = - 2.56 ± 0.72 mm; CAL = 1.75 ± 1.07 mm) at 90 days (p < 0.05). It was also observed significantly fewer residual periodontal pockets (PPD &ge; 5 mm) in the Test Group when compared to the Control Group at 90 days (p < 0.05). Regarding microbiological analysis, the Test Group presented proportions of red and orange complexes significantly lower and proportions of blue complex significantly higher than the Control Group at 90 days (p < 0.05). Immunological analysis demonstrated significantly lower levels of IL-1&beta; in the Control Group when compared to the Test Group at 14, 30 and 90 days (p < 0.05). Only the Test Group presented significantly higher IL-10 levels in relation to baseline values at 30 days (p < 0.05). Intra and inter-groups comparisons of the mean levels of TNF-&alpha; did not demonstrate significantly differences. IL-1&beta;/IL-10 ratio was significantly lower in the Test Group than in the Control Group at 90 days (p < 0.05). It can be concluded that repeated aPDT as an adjunct to SRP in the nonsurgical treatment of AP: i) significantly improves clinical periodontal parameters, reducing the need for further treatments at 90 days; ii) eliminates periodontal pathogens of red and orange complexes more effectively and iii) enhances the host immunoinflammatory response, decreasing the levels of proinflammatory cytokines and increasing the levels of anti-inflammatory cytokines.

1H and 13C{1H} NMR spectra of all the new compounds and crystallographic data are given in the Appendix. / Chapter 1 presents an overview of phthalocyanines including their general synthesis, properties, and applications. Special attention has been placed on the unsymmetrical analogues, and those which are efficient photosensitizers in photodynamic therapy. A brief account on BODIPYs as another versatile class of functional dyes is also given. / Chapter 2 describes the synthesis, spectroscopic characterization, photophysical properties, and in vitro photodynamic activities of three novel amphiphilic zinc(II) phthalocyanines substituted with one or two 3,4,5-tris(3,6,9-trioxadecoxy)benzoxy group(s). These compounds exhibit significantly higher photodynamic activities toward HepG2 and HT29 cell lines. The alpha-substituted analogue is particularly potent with IC50 values as low as 0.02 microM. The higher photodynamic activity of this compound can be attributed to its lower aggregation tendency in the culture media as shown by absorption spectroscopy and higher cellular uptake as suggested by the stronger intracellular fluorescence, resulting in a higher efficiency to generate reactive oxygen species inside the cells. / Chapter 4 focuses on a related series of 1,4-disubstituted zinc(II) phthalocyanines. These compounds possess two oligoethylene glycol methyl ether chains with various length at the 1,4-di-alpha-positions. The effects of the chain length on their aggregation, photophysical properties, cellular uptake, and in vitro photodynamic activities have been explored. / Chapter 5 presents the synthesis, characterization, and photophysical properties of another series of zinc(II) phthalocyanines conjugated with one, two or four isopropylidene protected glucofuranose unit(s) through a tetraethylene glycol linker. With these hydrophilic substituents, these macrocycles are highly soluble in common organic solvents and biological media. Their in vitro photodynamic activities toward HT29 and HepG2 cells have also been evaluated. Compared with the tetra-glucosylated phthalocyanines, which are almost nonphotocytotoxic, the mono- and di-glucosylated analogues exhibit a higher photodynamic activity. The di-alpha-substituted analogue is particularly potent with IC50 values as low as 0.03 microM. / Chapter 6 reports the synthesis, characterization, and photophysical properties of two novel conjugates of subphthalocyanine substituted axially with a BODIPY or distyryl-BODIPY moiety. Both systems absorb over a broad range in the visible region. They also exhibit a highly efficient photo-induced energy transfer process either from the excited BODIPY to the subphthalocyanine core or from the excited subphthalocyanine to the distyryl-BODIPY unit. The energy transfer quantum yields are close to unity for both of these conjugates. / Chapter 7 describes the preparation and photophysical properties of another two BODIPY and monostyryl-BODIPY conjugates which are linked to a silicon(IV) phthalocyanine core. These conjugates serve as excellent artificial photosynthetic models for the study of energy and electron transfer processes. Depending on the axial substituents, these conjugates exhibit predominantly a photo-induced energy or electron transfer process in toluene. / The related studies of a series of novel di-alpha-substituted zinc(II) phthalocyanines having two biocompatible triethylene glycol methyl ether chains or glycerol moieties are described in Chapter 3. Compared with the unsubstituted analogue, these compounds have a red-shifted Q band, and exhibit a relatively weaker fluorescence emission and higher efficiency to generate singlet oxygen. As a result, these compounds are promising candidates for photodynamic therapy. In vitro studies on HepG2 and HT29 cells have shown that they are highly photocytotoxic with IC50 values as low as 0.06 microM. / This thesis describes my synthetic studies on several series of functional zinc(II) phthalocyanines and boron dipyrromethenes (BODIPYs). Their applications as efficient photosensitizers in photodynamic therapy and light harvesting systems have also been explored. / Liu, Jianyong. / Adviser: Dennis Keepui Ng. / Source: Dissertation Abstracts International, Volume: 71-01, Section: B, page: 0326. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese.

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So, Cheung Wai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 106-117). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.iii / 摘要 --- p.v / List of Abbreviations --- p.vii / List of Figures --- p.viii / List of Tables --- p.x / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Candida albicans and candidiasis / Chapter 1.1.1 --- Historical background --- p.1 / Chapter 1.1.2 --- C. albicans infections --- p.2 / Chapter 1.1.3 --- Current challenges in the treatment of C. albicans --- p.3 / Chapter 1.2 --- Photodynamic therapy --- p.11 / Chapter 1.2.1 --- Historical aspects and development --- p.11 / Chapter 1.2.2 --- Basic principle of photodynamic therapy --- p.13 / Chapter 1.2.3 --- Light applicator --- p.16 / Chapter 1.2.4 --- Generations of photosensitizer --- p.17 / Chapter 1.2.5 --- Characteristics of phthalocyanines --- p.20 / Chapter 1.2.6 --- Photodynamic antimicrobial chemotherapy (PACT) --- p.22 / Chapter 1.3 --- Aim of present study --- p.24 / Chapter Chapter 2 --- Materials and Methods / Chapter 2.1 --- Synthesis of BAM-SiPc --- p.27 / Chapter 2.2 --- Preparation of BAM-SiPc solution --- p.27 / Chapter 2.3 --- Yeast strains and culture conditions --- p.28 / Chapter 2.4 --- Light source --- p.29 / Chapter 2.5 --- Assays of PDT with planktonic C. albicans / Chapter 2.5.1 --- Photodynamic treatment on planktonic cells --- p.30 / Chapter 2.5.2 --- Clonogenic assay --- p.32 / Chapter 2.5.3 --- Cellular uptake of BAM-SiPc --- p.32 / Chapter 2.5.4 --- Distribution of BAM-SiPc in planktonic cells / Chapter 2.5.4.1 --- Fluorescence microscopic analyses --- p.33 / Chapter 2.5.4.2 --- Confocal laser scanning microscopic (CLSM) analyses --- p.34 / Chapter 2.5.5 --- Determination of ROS level in planktonic cells --- p.34 / Chapter 2.5.6 --- Distribution of ROS in planktonic cells --- p.35 / Chapter 2.5.7 --- Effect of ROS inhibitors --- p.35 / Chapter 2.5.8 --- Membrane integrity assay --- p.36 / Chapter 2.6 --- Assays of PDT with C. albicans biofilm / Chapter 2.6.1 --- Biofilm formation --- p.37 / Chapter 2.6.2 --- Photodynamic treatment on C. albicans biofilm --- p.38 / Chapter 2.6.3 --- Viability assays / Chapter 2.6.3.1 --- XTT reduction assay --- p.38 / Chapter 2.6.3.2 --- Molecular probes staining --- p.40 / Chapter 2.6.4 --- Determination of ROS level in biofilm --- p.41 / Chapter 2.6.5 --- Distribution of BAM-SiPc in biofilm --- p.41 / Chapter 2.6.6 --- Photodynamic treatment on C. albicans from resuspended biofilm --- p.42 / Chapter 2.7 --- Statistical analysis --- p.42 / Chapter Chapter 3 --- Results / Chapter 3.1 --- BAM-SiPc mediated PDT on planktonic C. albicans / Chapter 3.1.1 --- Antifungal effect of BAM-SiPc on C. albicans / Chapter 3.1.1.1 --- PDT activities on different strains of C. albicans --- p.43 / Chapter 3.1.1.2 --- Effect of different densities of cells --- p.47 / Chapter 3.1.1.3 --- Effect of a washing step before illumination --- p.47 / Chapter 3.1.2 --- Optimization of PDT conditions with BAM-SiPc on C. albicans / Chapter 3.1.2.1 --- Time course study --- p.50 / Chapter 3.1.2.2 --- Light dose study --- p.50 / Chapter 3.1.3 --- Uptake of BAM-SiPc --- p.53 / Chapter 3.1.4 --- Distribution of BAM-SiPc in the planktonic cells / Chapter 3.1.4.1 --- Analysis with fluorescence microscopy --- p.56 / Chapter 3.1.4.2 --- Analysis with CLSM --- p.56 / Chapter 3.1.5 --- ROS production upon PDT treatment / Chapter 3.1.5.1 --- ROS level in the planktonic cells --- p.59 / Chapter 3.1.5.2 --- Distribution of ROS production --- p.61 / Chapter 3.1.5.3 --- Effect of different ROS inhibitors on BAM-SiPc's potency --- p.64 / Chapter 3.1.6 --- Membrane integrity --- p.66 / Chapter 3.2 --- BAM-SiPc mediated PDT on C. albicans biofilm / Chapter 3.2.1 --- Establishment of the biofilm model with 192887g --- p.69 / Chapter 3.2.2 --- Photodynamic treatment on 192887g biofilm / Chapter 3.2.2.1 --- Viability assay - XTT assay --- p.72 / Chapter 3.2.2.2 --- Viability assay ´ؤ LIVE/DEAD BacLight Bacterial Viability kit --- p.72 / Chapter 3.2.3 --- ROS level in the biofilm after PDT treatment --- p.75 / Chapter 3.2.4 --- Distribution of BAM-SiPc in the biofilm --- p.75 / Chapter 3.2.5 --- Photodynamic treatment on C. albicans from resuspended biofilm --- p.79 / Chapter Chapter 4 --- Discussion --- p.81 / Chapter 4.1 --- Antifungal effect of BAM-SiPc on the planktonic C. albicans --- p.81 / Chapter 4.2 --- Effects of different conditions on the photodynamic treatment with BAM- SiPc --- p.83 / Chapter 4.3 --- Mechanistic study of the antifungal effect of BAM-SiPc --- p.86 / Chapter 4.3.1 --- Interaction between BAM-SiPc and C. albicans --- p.86 / Chapter 4.3.2 --- ROS as mediator of cell damage --- p.89 / Chapter 4.3.3 --- Analysis of membrane integrity upon photodynamic treatment --- p.91 / Chapter 4.4 --- Establishment of the biofilm model of C. albicans --- p.92 / Chapter 4.5 --- In vitro effect of BAM-SiPc mediated PDT on C. albicans biofilm --- p.95 / Chapter Chapter 5 --- Conclusion and Future Perspectives / Chapter 5.1 --- Conclusion --- p.101 / Chapter 5.2 --- Future perspectives --- p.102 / References --- p.106

Orientador: Carla Raquel Fontana / Coorientador: Marlus Chorilli / Banca: Ana Claudia Pavarina / Banca: Natalia Mayumi Inada / Resumo: A acne vulgar é uma das dermatoses mais frequentes em jovens e a infecção causada pela bactéria Cutibacterium acnes (antigo Propionibacterium acnes) tem importante papel na patogênese da acne. Existem várias opções de tratamento que variam de acordo com a gravidade da doença, porém são associados com reações indesejadas e resistência aos antimicrobianos. A terapia fotodinâmica antimicrobiana (TFDa) então é proposta como tratamento alternativo para inativar C. acnes juntamente com a incorporação do fotossensibilizador (FS) em uma formulação tópica para otimizar a terapia. Este trabalho objetivou avaliar a eficácia in vitro da TFDa mediada pelo azul de metileno (AM) incorporado em hidrogel de quitosana e poloxamer (HG-AM) contra C. acnes em fase planctônica e biofilme. A viabilidade celular após TFDa foi avaliada através da quantificação das colônias formadas por mililitro de amostra (UFC/mL). Para caracterizar estruturalmente os HGs foram realizadas as análises oscilatórias e de comportamento de fluxo em reômetro de estresse controlado com geometria placa-cone e a bioadesão em pele de orelha de porco utilizando um texturômetro. A análise estatística dos dados feita foi a Análise de Variância (one way ANOVA) com pós-teste de Tukey. Os resultados deste estudo mostrou que a TFDa contra C. acnes foi eficaz utilizando HG-AM em fase plactônica. A concentração bactericida mínima foi de 12,5 µg/mL associada a uma fluência de 90 J/cm2. O biofilme de C. acnes não foi totalmente eliminad... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Acne vulgaris is one of the most frequent dermatosis in young people and the infection caused by the bacteria Cutibacterium acnes (formerly Propionibacterium acnes) plays an important role in the pathogenesis of acne. There are several treatments options that vary according to the severity of the disease, but are associated with unwanted reactions and antimicrobial resistance. Antimicrobial photodynamic therapy (aPDT) is then proposed as an alternative treatment to inactivate C. acnes together with the incorporation of the photosensitizer (PS) into a topical formulation to optimize therapy. This work aimed to evaluate the in vitro efficacy of methylene blue (MB) mediated TFDa incorporated in chitosan and poloxamer (HG-MB) hydrogels against planktonic and biofilm C. acnes. Cell viability after aPDT was evaluated by quantifying the colonies formed per milliliter of sample (CFU / mL). To characterize structurally the HG were performed the oscillatory and behavior of flow in a controlled stress rheometer with cone-plate geometry and bioadhesion in pig ear skin using a texture analyser. The statistical analysis of the data was the Analysis of Variance (one way ANOVA) with post-test of Tukey. The results of this study showed that aPDT was effective using HG-MB in planktonic phase. The minimum bactericidal concentration was 12.5 μg/mL associated with a fluence of 90 J/cm2 . The C. acnes biofilm was not totally eliminated by the aPDT with HG-MB under the conditions tested. The maximum microbial reduction achieved with HG-MB was 1.9 log10 with 75 μg/mL of the PS using 150 J/cm2 and 30 minutes biofilm incubation with HG-MB. HG at 0.25% of chitosan (HG1) was adequate for application to the skin surface because higher concentrations... (Complete abstract click electronic access below) / Mestre

Metallophthalocyanine complexes containing non-transition metals are very useful as sensitizers for photodynamic therapy, a cure for cancer that is based on visible light activation of tumour localized photo sensitizers. Excited sensitizers generate singlet oxygen as the main hyperactive species that destroy the tumour. Water soluble sensitizers are sought after for the convenience of delivery into the body. Thus, phthalocyanine (pc), tetrapyridinoporphyrazines (tppa) and tetramethyltetrapyridinoporphyrazines (tmtppa) with non-transition central metal atoms of Ge, Si, Sn and Zn were studied. First was the synthesis of these complexes, followed by their characterisation. The characterisation involved the use of ultraviolet and visible absorption spectroscopy, infrared spectroscopy, nuclear magnetic resonance spectroscopy, electrochemical properties and elemental analysis. Photochemical properties of the complexes were then investigated. Photolysis of these macrocycles showed two processes; -reduction of the dye and photobleaching, which leads to the disintegration of the conjugated chromophore structure of the dye. Photobleaching is the reductive quenching of the excited state of the sensitizers. The intensity of the quenching decreased progressively from tmtppa, tppa to pc metal complexes with photobleaching quantum yields, 6.6 x 10.5⁻¹, 1.8 x 10.5⁻¹ and 5.4 x 10⁻⁶ for Zntmtppa, Zntppa and Znpc, respectively. Efficiency of singlet oxygen sensitization is solvent dependent with very different values obtained for the same compound in different solvents, for example, 0.25 and 0.38 were observed as singlet oxygen quantum yields for Gepc complex in DMSO and DMF respectively. In DMSO the efficiency of ¹O₂ generation decrease considerably from pc to tppa and finally tmtppa. In water Getmtppa exhibits much higher singlet oxygen quantum yield, hence promising to be effective as a sensitizer for photodynamic therapy.

Dye-sensitized solar cell (DSSC) has attracted increasing interest as a promising hybrid organic-inorganic solar cell. At the heart of the device is a photosensitizer, which is anchored onto a wide-bandgap semiconducting metal oxide. It harvests solar light and transfers the energy via electron transfer to a suitable material (e.g. TiO2) to produce electricityas opposed to chemical energy in plant. The topic of this thesis focuses on the design and synthesis of metal-free organic dyes for applications in DSSCs. Specific attention has been paid to the correlation between the molecular structures and physical properties, as well as their performances in DSSCs. Chapter 1 presents the major components and working principle of DSSC, following by a brief overview of the development of organic dyes and their application in DSSCs. In chapter 2, we have designed two types of new phenothiazine-based dyes to investigate the positioning effect a donor group on the cell performance. The structural features of a donor aryl group at the C(7) position of phenothiazine core extend the π-conjugation of the chromophore and efficiently suppress the dye aggregation on TiO2 film. As a result, Type 1 dyes have better light harvesting properties in contact with TiO2 films, and give much better photovoltaic performance than Type 2 dyes. Chapter 3 presents the synthesis and characterization of a series of simple phenothiazine-based dyes, in which, a linear electron-rich (4-hexyloxy)phenyl group at C(7) of the phenothiazine periphery as the donor, and an alkyl chain with different length at N(10). The dye molecules show a linear shape which is favorable for the formation of a compact dye layer on the TiO2 surface, while their butterfly conformations can sufficiently inhibit molecular aggregation. Moreover, the alkyl substituents with different chain length at N(10) could further optimize the performance through complete shielding the surface of TiO2 from the Iˉ/I3ˉ electrolyte. Under simulated AM 1.5G irradiation, the PT-C6 based DSSC produces a short-circuit photocurrent of 15.32 mAcm−2, an open-circuit photovoltage of 0.78 V, a fill factor of 0.69, corresponding to a power conversion efficiency (PCE) of 8.18%. Moreover, we designed a stepwise approach for co-adsorption of the organic dye PT-C6 with a porphyrin dye (ZnP) for DSSCs. Upon optimization, the device made of the PT-C6 + ZnP system yielded Jsc = 19.36 mA cm-2, Voc =0.735 V, FF = 0.71 and η = 10.10%. In chapter 4, we further developed five organic dyes appended with T, TT, E, ET, or EE (T and E denote thiophene and 3,4-ethylenedioxythiophene (EDOT), respectively) on the C(7) atom of phenothiazine core as electron donors. We have also analyzed the structure-performance corelations of dye molecules in the aspect of dye aggregation, electron injection, dye regeneration and interfacial charge recombination of electrons with electrolytes and/or oxidized dye molecules, through DFT calculation, impedance analysis and transient photovoltage studies. In chapter 5, we extended our studies by using phenothiazine as a building block to construct 3D bulky organic dyes. We systematically investigated the influence of 3D bulky substituents on dye aggregation and charge recombination, as well as photovoltaic performance of DSSCs. The molecular design strategy demonstrates that high Voc can be realized by employing 3D-phenothiazine dyes featuring a bulky substituent, such as, hexylcarbazole and dihexylfluorene units. Impressively, the co-adsorbent-free DSSCs based on dye TP3 exhibits a photovoltaic performance with efficiency up to 8.00 %. In order to realize a panchromatic absorption and further enhance the energy conversion efficiency of DSSCs, we also designed a stepwise approach for co-adsorption of the organic dye TP3 with a NIR dye YR6 for co-sensitized DSSCs. Upon optimization, the device made of the TP3 + YR6 system yielded Jsc = 19.18 mA cm-2, Voc =0.721 V, FF = 0.712 and η = 9.84 %. The power-conversion efficiency is the highest reported efficiency for a squaraine dye-based co-sensitized panchromatic DSSCs. From chapters 6 and 7, a series of new simple panchromatic dyes based on thiadiazolo[3,4-c]pyridine (PyT) have been designed for panchromatic DSSCs. These new organic dyes exhibit broad absorption spectrum in the range of 300~850 nm and high molar extinction coefficients. The electrochemical analyses demonstrate that the incorporation of the auxiliary electron-deficient thiadiazole[3,4-c]pyridine unit can fine-tune the HOMO and LUMO energy levels and red-shift the absorption spectra to NIR region. The overall conversion efficiencies of liquid-electrolyte DSSCs based on these sensitizers range from 0.46 to 6.30 %. We draw some conclusions in chapter 8 together with the outlooks in DSSCs

This thesis describes the synthesis and characterization of a series of photosensitizers, transition metal-containing polymers and small organic molecules for dye-sensitized solar cells and organic solar cells. To begin with, a brief overview on the background of dye-sensitized solar cells (DSSCs) and organic solar cells was presented in Chapter 1. In Chapter 2, a series of novel donor-acceptor-π-acceptor bithiazole-based and fluorenone-based organic dyes for dye-sensitized solar cells were successfully synthesized and fully characterized. We discovered that the performance of the photovoltaic devices depends significantly on the nature and strength of the electron-donating end group along the conjugated main. Some of the materials have been found to show higher power conversion efficiency of 4.71% (Voc = 565 mV, Jsc = 11.71 mA cm–2, FF = 0.71) under AM 1.5 irradiation (100 mW cm–2). In Chapter 3, ten novel donor-donor-π-acceptor organic dyes for dye-sensitized solar cells have been synthesized and applied for the fabrication of DSSCs, including six dibenzothiophene-based photosensitizers and carbazole-based photosensitizers. All the dyes have efficient charge injection from the excited sensitizer molecule to TiO2 conduction band and can provide ample driving force for efficient dye regeneration best overall light to electricity conversion efficiency of 5.28% (Voc = 0.70 V, Jsc = 11.06 mA cm–2, FF = 0.68) under AM 1.5 irradiation, which reached 73% with respect to that of an N719-based device fabricated under similar fabrication conditions. Besides, nine novel di-anchoring organic sensitizers employing two different electron-donating cores, which are the fluorene and carbazole units, and two symmetrical anchoring cyanoacrylic acid (acceptor) termini have been synthesized and studied for their applications in DSSCs in Chapter 4. In Chapter 5, four new platinum polyyne polymers were prepared via the Sonogashira-type dehydrohalogenation reaction between the ethynyl precursor and trans-Pt(PBu3)2Cl2. All of the polymers are air-stable and well characterized by different spectroscopic methods and photophysical measurements. Their photovoltaic behaviors were fully investigated. Their model compounds were also prepared and studied. In Chapter 6, a series of new organic small molecules were designed and synthesized comprising head-to-head coupled heylthiophene, dithienosilole and dithienogermole units. They exhibited broad absorption peaks with favorable spectral overlap with the solar spectrum. These seven small molecules have been applied to presented. Among these molecules, the highest PCE of 4.93% was achieved with a Voc = 0.79 V, Jsc = 1.22 mA cm-2 and FF = 0.51 under illumination of an AM 1.5 solar cell simulator. Finally, Chapters 7 and 8 present the concluding remarks and the experimental details of the work described in Chapters 2−6

O tratamento da doença periodontal consiste na remoção mecânica do biofilme, sendo que terapias complementares como a terapia fotodinâmica antimicrobiana (aPDT) podem melhorar os resultados obtidos. Este trabalho avaliou in vitro o efeito dos corantes azul de toluidina e azul de metileno com distintos parâmetros de laser (70; 100mW) e LED em Aggregatibacter actinomycetemcomitans (A.a) em suspensão. O primeiro experimento avaliou efeito bactericida de diferentes concentrações dos dois corantes sozinhos (0,05; 0,1; 0,5, 1,0; 2,0; 5,0; 10 mg/ml). O segundo foi dividido nos seguintes grupos: controles positivo e negativo (gentamicina), grupos somente com luz aplicada, grupos com três concentrações (0,05; 0,1; 10 mg/ml) de corante sozinhos ou associados ao laser de baixa intensidade (660 nm; 2,91 e 4,16 W/cm2; 70 e 100mW; 45 J/cm2; 0,024 cm2; 12 e 18s) e LED (627 ± 10 nm; 150mW/cm2; 10,5 mW; 20 J/cm2; 0,07cm2; 123s). Os dados foram analisados pelo teste ANOVA complementado por Tukey (p<0,05). Os resultados demonstraram que ambos os corantes na concentração de 10 mg/ml sozinhos ou associados com laser (ambas as potências) ou LED causaram 100 % de morte bacteriana semelhante ao controle negativo (p>0,05). Com isso, pode-se concluir que aPDT pode eliminar o A.a. de forma dependente da concentração do corante. / The main treatment of periodontal disease is the mechanical removal of biofilm. Adjuvant therapies as antimicrobial photodynamic therapy (aPDT) may offer better results. The aim of this in vitro study was to evaluate the effect of toluidine and methylene blue dyes, associated to red laser (70; 100mW) and LED on elimination of a suspension of Aggregatibacter actinomycetemcomitans (A.a). A first test evaluated the bactericidal effect of various concentrations of both dyes (0.05; 0.1; 0.5, 1.0; 2.0; 5.0, 10 mg/ml) in absence of light. In the second test, the experimental groups consisted of positive and negative (gentamicin) controls, groups with three concentrations (0.05; 0.1,10 mg/ml) of dyes alone of associated to low level laser (660 nm; 2.91 and 4.16 W/cm2; 70 and 100mW; 45 J/cm2; 0.024 cm2; 12 and 18s) and LED (627 ± 10 nm; 150mW/cm2; 10.5 mW; 20 J/cm2; 0.07cm2; 123s). Data were analyzed by ANOVA complemented by Tukeys test (p<0.05). The results showed that both dyes, with 10 mg/ml, alone or associated to laser and LED caused 100% of death as the negative control (p>0.05). It can be concluded that aPDT is capable of eliminate A.a depending of the dye concentration.