Terapia fotodinâmica em microorganismos cariogênicos: estudo in vitro
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Data
2012-02-24
Autores
Esteban Florez, Fernando Luis [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O uso indiscriminado dos antibióticos e seu mecanismo de ação levaram ao desenvolvimento de cepas bacterianas altamente resistentes e de maior virulência. Estas cepas causam doenças muito mais agressivas e de difícil tratamento, constituindo-se um dos principais desafios enfrentados por profissionais da área da saúde. Como a terapia fotodinâmica antimicrobiana (TFDA) baseia seu mecanismo de ação em reações oxidativas não especificas, esta passou a ser uma alternativa interessante para o tratamento de todas as doenças de origem microbiana, uma vez que, nem bactérias, nem vírus ou fungos tem capacidade de desenvolver resistência a TFDA. Considerando que a carie dental é uma doença de origem bacteriana especifica e que a eficácia da TFDA depende do tipo e dose de energia luminosa utilizada, do fotossensibilizador e da taxa de oxigênio nos tecidos a serem tratados, decidimos investigar a viabilidade da TFDA para prevenção e tratamento da cárie dental. Para tal, foram realizados 3 estudos: 1) Revisão critica da literatura sobre fotossensibilizadores utilizados para controle antimicrobianos de Streptococcus mutans. 2) Avaliação do efeito antibacteriano de três fotossensibilizadores (curcumina, hipericina e hematoporfirina) sobre Streptococcus mutans em suspensões planctônicas e 3) Avaliação do efeito antibacteriano de três fotossensibilizadores (curcumina, hipericina e photogem®) Esteban Florez FL. Terapia Fotodinâmica em microrganismos cariogênicos – Estudo in vitro. [Tese de doutorado]. Araraquara: sobre biofilme maduro formado a partir de cepa de Streptococcus mutans. Dos fotossensibilizadores utilizados a hipericina foi a que apresentou maior efeito antimicrobiano sobre suspensão planctônica. Foi comprovado que a eficácia da TFDA esta diretamente relacionada com o tipo...
The indiscriminate use of antibiotics and its mechanisms of action led to the development of highly resistant bacterial strains and more virulent ones. This strains can cause diseases much more aggressive and difficult to treat, and in that way they consist in one of the major challenges to the health care professionals. As the antimicrobial photodynamic therapy (APDT) it is based on non-specific oxidative reaction, this is now considered as an interesting alternative to treat all diseases from bacterial origins, once that, neither bacterias, neither viruses nor fungi can develop acquired resistance from the therapy. Taking into consideration that dental caries is a specific bacterial disease and that the APDT's efficiency is directed related to factors as, wavelength, energy dose, photosensitizer used, and with the oxygen present in the target tissue, we have decided to investigate the APDT to prevent and treat dental decay. To accomplish that, it was realized three studies: 1) Critical Literature revision about photosensitizers used to control S.mutans. 2) Evaluation of the antimicrobial effect of three different photosensitizers (Curcumin, Hypericin and Hematoporfirin) over Streptococcus mutans in planktonic cultures and 3) Evaluation of the antimicrobial effect of three photosensitizers (Curcumin, Hypericin and Hematoporfirin) over mature biofilms obtained from Streptococcus mutans strains. From the photosensitizers used Hypericin was the one that showed the most antibacterial observed effect on the planktonic cultures. It was demonstrated by our data that the APDT efficacy is directly related to the time of irradiation of the samples, with the kind of photosensitizer used, its concentration and with the energy dose delivered. None of the proposed protocols were able to show any significant effect over the microorganisms when in biofilm... (Complete abstract click electronic access below)
The indiscriminate use of antibiotics and its mechanisms of action led to the development of highly resistant bacterial strains and more virulent ones. This strains can cause diseases much more aggressive and difficult to treat, and in that way they consist in one of the major challenges to the health care professionals. As the antimicrobial photodynamic therapy (APDT) it is based on non-specific oxidative reaction, this is now considered as an interesting alternative to treat all diseases from bacterial origins, once that, neither bacterias, neither viruses nor fungi can develop acquired resistance from the therapy. Taking into consideration that dental caries is a specific bacterial disease and that the APDT's efficiency is directed related to factors as, wavelength, energy dose, photosensitizer used, and with the oxygen present in the target tissue, we have decided to investigate the APDT to prevent and treat dental decay. To accomplish that, it was realized three studies: 1) Critical Literature revision about photosensitizers used to control S.mutans. 2) Evaluation of the antimicrobial effect of three different photosensitizers (Curcumin, Hypericin and Hematoporfirin) over Streptococcus mutans in planktonic cultures and 3) Evaluation of the antimicrobial effect of three photosensitizers (Curcumin, Hypericin and Hematoporfirin) over mature biofilms obtained from Streptococcus mutans strains. From the photosensitizers used Hypericin was the one that showed the most antibacterial observed effect on the planktonic cultures. It was demonstrated by our data that the APDT efficacy is directly related to the time of irradiation of the samples, with the kind of photosensitizer used, its concentration and with the energy dose delivered. None of the proposed protocols were able to show any significant effect over the microorganisms when in biofilm... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Streptococcus mutans, Cáries dentárias, Fotoquimioterapia
Como citar
ESTEBAN FLOREZ, Fernando Luis. Terapia fotodinâmica em microorganismos cariogênicos: estudo in vitro. 2012. 152 f. Tese (doutorado) - Universidade Estadual Paulista - Faculdade de Odontologia de Araraquara, 2012.