Viability of fibroblasts cultured under nutritional stress irradiated with red laser, infrared laser, and red light-emitting diode

Author(s)

Ricci Volpato, Luiz Evaristo ^[1] ; de Oliveira, Rodrigo Cardoso ^[2] ; Espinosa, Mariano Martinez ^[3] ; Bagnato, Vanderley Salvador ^[4] ; Machado, Maria A. A. M. ^[2]

Affiliation

^[1] Univ Cuiaba, Cuiaba Sch Dent, BR-78043330 Cuiaba, MT - Brazil

^[2] Univ Sao Paulo, Bauru Sch Dent, BR-17012901 Bauru, SP - Brazil

^[3] Univ Fed Mato Grosso, Dept Stat, BR-78060900 Cuiaba, MT - Brazil

^[4] Univ Sao Paulo, Phys Inst Sao Carlos, BR-13566590 Sao Paulo - Brazil

• Document type: Journal article
• Source: Journal of Biomedical Optics; v. 16, n. 7 JUL 2011.
• Web of Science Citations: 26

Abstract

Phototherapy is noninvasive, painless and has no known side effect. However, for its incorporation into clinical practice, more well-designed studies are necessary to define optimal parameters for its application. The viability of fibroblasts cultured under nutritional stress irradiated with either a red laser, an infrared laser, or a red light-emitting diode (LED) was analyzed. Irradiation parameters were: red laser (660 nm, 40 mW, 1 W/cm(2)), infrared laser (780 nm, 40 mW, 1 W/cm(2)), and red LED (637 +/- 15 nm, 40 mW, 1 W/cm(2)). All applications were punctual and performed with a spot with 0.4 mm(2) of diameter for 4 or 8 s. The Kruskal-Wallis test and analysis of variance of the general linear model (p <= 0.05) were used for statistical analysis. After 72 h, phototherapy with low-intensity laser and LED showed no toxicity at the cellular level. It even stimulated methylthiazol tetrazolium assay (MTT) conversion and neutral red uptake of fibroblasts cultured under nutritional stress, especially in the group irradiated with infrared laser (p = 0.004 for MTT conversion and p < 0.001 for neutral red uptake). Considering the parameters and protocol of phototherapy used, it can be concluded that phototherapy stimulated the viability of fibroblasts cultured under nutritional deficit resembling those found in traumatized tissue in which cell viability is reduced. (C) 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). {[}DOI: 10.1117/1.3602850] (AU)

• FAPESP's process: 07/08367-0 - Evaluation of the influence of the irradiation with laser in low intensity in the proliferative and metabolic behavior of human osteoblasts in vitro
• Grantee: Camila Peres Buzalaf
• Support Opportunities: Regular Research Grants