title: Photodynamic therapy associating Photogem and blue LED on L929 and MDPC-23 cell culture.
abstract: To evaluate the cytotoxicity of PDT (photodynamic therapy) with Photogem associated to blue LED (light-emitting diode) on L929 and MDPC-23 cell cultures, 30000 cells/cm2 were seeded in 24-well plates for 48 h, incubated with Photogem (10, 25 or 50 mg/l) and irradiated with an LED source (460+/-3 nm; 22 mW/cm2) at two energy densities (25.5 or 37.5 J/cm2). Cell metabolism was evaluated by the MTT (methyltetrazolium) assay (Dunnet's post hoc tests) and cell morphology by SEM (scanning electron microscopy). Flow cytometry analysed the type of PDT-induced cell death as well and estimated intracellular production of ROS (reactive oxygen species). There was a statistically significant decrease of mitochondrial activity (90% to 97%) for all Photogem concentrations associated to blue LED, regardless of irradiation time. It was also demonstrated that the mitochondrial activity was not recovered after 12 or 24 h, characterizing irreversible cell damage. PDT-treated cells presented an altered morphology with ill-defined limits. In both cell lines, there was a predominance of necrotic cell death and the presence of Photogem or irradiation increased the intracellular levels of ROS. PDT caused severe toxic effects in normal cell culture, characterized by the reduction of the mitochondrial activity, morphological alterations and induction of necrotic cell death.
authors: Department of Dental Materials and Prosthodontics, São Paulo State University, Araraquara School of Dentistry, Araraquara, SP, Brazil.
authors: Ana Paula Dias
authors: AP
authors: Ribeiro
authors: Ana Cláudia
authors: AC
authors: Pavarina
authors: Flávia Zardo
authors: FZ
authors: Trindade
authors: Natália Mayumi
authors: NM
authors: Inada
authors: Vanderlei Salvador
authors: VS
authors: Bagnato
authors: Carlos Alberto
authors: CA
authors: de Souza Costa
mesh_terms: D000818:Animals; D017209:Apoptosis; D002460:Cell Line; D005434:Flow Cytometry; D008027:Light; D051379:Mice; D008855:Microscopy, Electron, Scanning; D008928:Mitochondria / Q000187:drug effects / Q000528:radiation effects; D009336:Necrosis; D010778:Photochemotherapy / Q000009:adverse effects*; D017319:Photosensitizing Agents / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species