title: Evaluation of the photobiomodulation in L929 cell culture.
abstract: Low-level laser therapy has become an important tool for bio-modulation process. It can induce stimulatory or inhibitory effects according to cell behavior at specific irradiation. Our objective was to determine L929 cell line response to irradiation at λ 685 and 830 nm, concentrations of 5 and 10% fetal bovine serum and different energy densities of 0.1, 0.5, 1, 2, 3, 5, 7, 10, 20, and 30 J/cm(2). Thus, cells were plated at 1 × 10(5) cells/mL and irradiated with semiconductor laser As-Ga-Al. Twenty-four hours after irradiation, cells were subjected to MTT, neutral red, crystal violet tests, and cell staining was performed using the kit Alexa Fluor 488 Annexin V-FITC and propidium iodide. Our results showed that low-level laser therapy stimulates effect when the energy density is 5 to 3030 J/cm(2) and inhibits effects on energy density 0.1 to 3 J/cm(2). This inhibitory effect was evidenced by the absence of dead cells labeled, decreased cell density, and by the absorption of neutral red in intact cells. The study also demonstrated that fetal bovine serum, at different concentrations, did not affect response of the cells after irradiation.
authors.affiliation: Laboratory of Tissue and Cell Biology, Development and Research Institute, Universidade do Vale do Paraíba (UNIVAP), Urbanova, 12244-000 São José dos Campos, Brazil Laboratory of Dynamics of Cellular Compartments, Development and Research Institute, Universidade do Vale do Paraíba (UNIVAP), Urbanova, 12244-000 São José dos Campos, Brazil.
authors.forename: Juliana Mangolin
authors.initials: JM
authors.lastname: Marques
authors.affiliation: Laboratory of Dynamics of Cellular Compartments, Development and Research Institute, Universidade do Vale do Paraíba (UNIVAP), Urbanova, 12244-000 São José dos Campos, Brazil cpsoares@univap.br.
authors.forename: Cristina
authors.initials: C
authors.lastname: Pacheco-Soares
authors.affiliation: Laboratory of Tissue and Cell Biology, Development and Research Institute, Universidade do Vale do Paraíba (UNIVAP), Urbanova, 12244-000 São José dos Campos, Brazil.
authors.forename: Newton Soares
authors.initials: NS
authors.lastname: Da Silva
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects; D005347:Fibroblasts / Q000528:radiation effects*; D007834:Lasers; D008027:Light; D051379:Mice; D013194:Staining and Labeling
keywords: Bio-modulation; inhibition; low-power laser; proliferation