LUIS CLAUDIO SUZUKI
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Artigo IPEN-doc 25857 Effect of photodynamic antimicrobial chemotherapy on Candida albicans in the presence of glucose2019 - OLIVEIRA-SILVA, TAMIRES de; ALVARENGA, LETICIA H.; LIMA-LEAL, CINTIA; GODOY-MIRANDA, BIANCA; CARRIBEIRO, PAMELA; SUZUKI, LUIS C.; RIBEIRO, MARTHA S.; KATO, ILKA T.; PAVANI, CHRISTIANE; PRATES, RENATO A.Background: Candida albicans is an opportunistic commensal microorganism, often associated with severe infections in immunosuppressed individuals. C. albicans has hexose transporters that may favor the intracellular accumulation of photosensitizer (PS). the aims of this study were to investigate the influence of glucose load on photodynamic antimicrobial chemotherapy (PACT); and the role that membrane transport system plays on this therapy in the presence of glucose. Material and methods: Strains of C. albicans were selected: ATCC 10231, YEM 12, YEM 13, YEM 14 and YEM 15. All strains were grown aerobically on Sabouraud agar and incubated at 30 °C for 24 h. The strains were treated with and without glucose, and divided into Control (no treatment), LED light (660 nm, 166 mW/cm2), Photosensitizer (100 μM methylene blue) and PACT at 1, 3 and 6 min of irradiation groups. The colony forming units were counted and data submitted to statistical analysis (ANOVA) and Tukey's test. The concentration of methylene blue (MB) outside the yeast was measured by fluorescence spectroscopy. Results: PACT inactivate C. albicans and the presence of glucose did not affect the killing effect for most strains. Only YEM12 was partially affected by its presence. Regarding efflux systems, ABC overexpressing strain showed a protective effect on the yeast cells. We observed that yeast with overexpression of major facilitator superfamily (MFS) membrane pore tended to accumulate more MB in its cytoplasm, whereas strains that overexpressed ABC pumps (ATP-binding cassette transporters) tended to decrease MB uptake and survive the photodynamic challenge. Conclusion: Presence of glucose showed a small effect on PACT . The accumulation of MB on yeast induces more photodynamic inactivation; however, the photodynamic efficacy depends on the type and characteristics of the microbial strain.Artigo IPEN-doc 23521 Glucose modulates antimicrobial photodynamic inactivation ofCandida albicans in biofilms2017 - SUZUKI, LUIS C.; KATO, ILKA T.; PRATES, RENATO A.; SABINO, CAETANO P.; YOSHIMURA, TANIA M.; SILVA, TAMIRES O.; RIBEIRO, MARTHA S.Candida albicans biofilm is a main cause of infections associated with medical devices such as catheters,contact lens and artificial joint prosthesis. The current treatment comprises antifungal chemotherapy thatpresents low success rates. Photodynamic inactivation (PDI) involves the combination of a photosensitiz-ing compound (PS) and light to generate oxidative stress that has demonstrated effective antimicrobialactivity against a broad-spectrum of pathogens, including C. albicans. This fungus senses glucose induc-ing an upregulation of membrane transporters that can facilitate PS uptake into the cell. The aim ofthis study was to evaluate the effects of glucose on methylene blue (MB) uptake and its influence onPDI efficiency when combined to a red LED with central wavelength at = 660 nm. C. albicans biofilmswere grown on hydrogel disks. Prior to PDI assays, MB uptake tests were performed with and withoutglucose-sensitization. In this system, the optimum PS administration was determined as 500 M of MBin contact with the biofilm during 30 min before irradiation. Irradiation was performed during 3, 6, 9, 12,15 and 18 min with irradiance of 127.3 mW/cm2. Our results showed that glucose was able to increaseMB uptake in C. albicans cells. In addition, PDI without glucose showed a higher viability reduction until6 min; after 9 min, glucose group demonstrated a significant decrease in cell viability when compared toglucose-free group. Taken together, our data suggest that glucose is capable to enhance MB uptake andmodulate photodynamic inactivation of C. albicans biofilm.Artigo IPEN-doc 20784 Estudo comparativo entre dois comprimentos de onda no efeito fotodinâmico em biofilmes de Candida albicans2014 - SUZUKI, L.C.; YOSHIMURA, T.M.; KATO, I.T.; PRATES, R.A.; RIBEIRO, M.S.Tese IPEN-doc 20735 Estudo in vitro da terapia fotodinâmica antimicrobiana em Candida albicans mediada por azul de metileno e glicose2015 - SUZUKI, LUIS C.Neste estudo foi proposto um modelo de formação de biofilme fúngico formado por Candida albicans em dois diferentes substratos associado ou não à glicose para o estudo dos efeitos da terapia fotodinâmica (PDT) utilizando o azul de metileno (AM) como fotossensibilizador, avaliando os efeitos de dois comprimentos de onda distintos incluindo a investigação na captação do AM quando sensibilizados previamente com a glicose. Foi avaliada a susceptibilidade da levedura em suspensão de células crescidas por 24 h (início da fase estacionária) com e sem a adição prévia da glicose. Foram investigadas duas linhagens de C. albicans para a padronização do biofilme, ATCC 90028 e ATCC 10231. Com os biofilmes formados, avaliamos a captação de AM para determinarmos a mais eficiente concentração e tempo de pré-irradiação (PIT). Por último, avaliamos sua sensibilidade à PDT em dois comprimentos de onda distintos (λ = 645 nm e λ = 660 nm) em função do tempo de irradiação (potência = 16 mW, taxa de fluência = 127,3 mW/cm2). A linhagem de célula que possibilitou a formação de biofilme foi a ATCC 10231 em discos de hidrogel. A menor concentração que possibilitou uma melhor captação do AM foi de 500 μM com um PIT de 30 min e em contato prévio com a glicose 50 mM por 90 min. O comprimento de onda mais eficiente, que promoveu redução em leveduras e biofilmes foi o de λ = 660 nm, reduzindo melhor no estudo de leveduras quando sensibilizados com glicose. Nos biofilmes, a redução foi iniciada mais precocemente sem a adição de glicose (com 6 min de irradiação e fluência = 46 J/cm2), porém, em 12 min (fluência = 92 J/cm2) o grupo com glicose passou a ter maior eficiência.Resumo IPEN-doc 14811 Strategies to optimize photodynamic antimicrobial therapy2009 - RIBEIRO, M.S.; GARCEZ, A.S.; NUNEZ, S.C.; KATO, I.T.; SUZUKI, L.C.; PRATES, R.A.Resumo IPEN-doc 16001 Candida albicans biofilm alterations during photodynamic therapy by optical coherence tomography video monitoring2010 - FREITAS, ANDERSON Z. de; SUZUKI, LUIS C.; PRATES, RENATO A.; RAELE, MARCUS P.; AMARAL, MARCELLO M.; RIBEIRO, MARTHA S.Resumo IPEN-doc 11840 Azul de metileno, verde de malaquita, indocianina verde e veterporfirina: acao fotodinamica antimicrobiana sobre Escherichia coli2007 - PRATES, R.A.; SUZUKI, L.C.; YAMADA JUNIOR, A.M.; RIBEIRO, M.S.Artigo IPEN-doc 14339 Parametros de irradiacao influenciam na inativacao de leveduras tratadas com terapia fotodinamica2009 - PRATES, RENATO A.; SILVA, ERIQUES G. da; SUZUKI, LUIS C.; PAULA, CLAUDETE R.; RIBEIRO, MARTHA S.Artigo IPEN-doc 14837 The irradiation parameters investigation of photodynamic therapy on yeast cells2008 - PRATES, RENATO A.; SILVA, ERIQUES G. da; YAMADA JUNIOR, AECIO M.; SUZUKI, LUIS C.; PAULA, CLAUDETE R.; RIBEIRO, MARTHA S.Artigo IPEN-doc 15656 Real time optical coherence tomography monitoring of Candida albicans biofilm in vitro during photodynamic treatment2010 - SUZUKI, LUIS C.; PRATES, RENATO A.; RAELE, MARCUS P.; FREITAS, ANDERSON Z. de; RIBEIRO, MARTHA S.