RESUMO
OBJECTIVES: The main focus of this research was to investigate the photodynamic therapy (PDT), in vitro, acting on Streptococcus mutans and fibroblasts. A hand held photopolymerizer (HHP) and a classical photosensitizer (Rose Bengal) were used to induce photodynamic response. METHODS: S. mutans and fibroblast were treated with different concentrations of Rose Bengal (0-50 microM) irradiated with light (400-500 nm) for different time periods (0-40s) and then cell viability was evaluated. RESULTS: It was observed that the light (per se) is not toxic and in the dark Rose Bengal is toxic to the cells tested only at concentrations above 2.5 microM. Under light exposure concentrations of Rose Bengal above 0.5 microM all S. mutans were killed with no cytotoxic effects to fibroblasts. CONCLUSIONS: For the purpose of this work, the photoactivation of Rose Bengal, using the HHP, inactivated the bacteria without affecting the fibroblast viability.
Assuntos
Luz , Fotoquimioterapia , Fármacos Fotossensibilizantes/toxicidade , Rosa Bengala/toxicidade , Streptococcus mutans/efeitos da radiação , Técnicas Bacteriológicas , Técnicas de Cultura de Células , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Relação Dose-Resposta a Droga , Fibroblastos/efeitos dos fármacos , Fibroblastos/efeitos da radiação , Humanos , Fotoquimioterapia/instrumentação , Streptococcus mutans/efeitos dos fármacos , Fatores de TempoRESUMO
Changes in hepatic paracellular permeability were investigated during the development of cholephilic dye-induced cholestasis in rats. For this purpose, four dyes with different cholestatic potency (phenol red, sulfobromophthalein, bromcresol green and rose bengal) were infused at a high, potentially damaging dose (280 nmol/min per 100 g body wt., i.v.), and changes in paracellular permeability were continuously monitored by measuring the access into bile of the permeability probe -14C-sucrose. The cholestatic potency of the different dyes was: rose bengal > bromcresol green > sulfobromophthalein > phenol red. All dyes increased [14C]sucrose bile-to-plasma ratio, producing a displacement towards curves of higher permeability. The capability of the dyes to increase biliary permeability followed the same order as their respective cholestatic potencies. The possible implications of the present results for cholephilic dye-induced cholestasis are discussed.