Photobiomodulation effect of red LED (630 nm) on the free radical levels produced by pulp cells under stress conditions

Abstract

The aim of this study was to assess the ability of red light emitting diodes (LED) to modulate oxidative stress in human dental pulp fibroblasts (HDPFs) when different irradiation parameters are employed. Cells from primary teeth were seeded (100,000 cells/well) in 24-well plates in culture medium (DMEM). At 24 h after incubation, the culture medium was replaced with DMEM containing 10 μg/mL lipopolysaccharide (LPS). Thereafter, the cells were irradiated (LED 630 nm, 0.04 W/cm 2 and 0.08 W/cm 2 ) at 0 J/cm 2 (control group), 4 J/cm 2 , 15 J/cm 2 , and 30 J/cm 2 ; and their viability (MTT assay), number (Trypan Blue), synthesis of nitric oxide (NO) (Griess reagent), and reactive oxygen species (ROS) (fluorescence probe, DCFH-DA) were assessed. The Kruskal-Wallis and Mann-Whitney statistical tests using Bonferroni correction were employed (significance level of 5%). Compared to that in control fibroblasts, increased viability was observed in HDPFs exposed to LPS and irradiated with 15 J/cm 2 and 30 J/cm 2 at 0.04 W/cm 2 and 4 J/cm 2 and 15 J/cm 2 at 0.08 W/cm 2 (p < 0.05). Exposure to 4 J/cm 2 at 0.04 W/cm 2 and 15 J/cm 2 and 30 J/cm 2 at 0.08 W/cm 2 modulated the oxidative stress in cells relative to that observed in non-irradiated LPS-treated pulp cells (p < 0.05). It was concluded that the irradiation strategies of using red LED with radiant exposures of 15 J/cm 2 and 30 J/cm 2 at 0.04 W/cm 2 and 15 J/cm 2 at 0.08 W/cm 2 were the best parameters to decrease NO and ROS concentration and to stimulate viability of HDPFs exposed to LPS challenge.

Polynaphthalene-Based Oxazaborinine Complexes Formulated as Red Light Emitters and High-Performance Asymmetric Supercapacitors

“…The PDMS composite of TNB can apply to the red LED production as a high CRI value (89%), with CCT 1561 K recorded. The red light emitted by the TNB / PDMS composite at 632 nm can have several effects in the biological and biomedical fields for which 630 nm red LED was already established . The photostability of composites was also analyzed by continuously irradiating the films with UV–vis light for 40 min (Figures S35 and S36).…”

“…The red light emitted by the TNB/PDMS composite at 632 nm can have several effects in the biological and biomedical fields for which 630 nm red LED was already established. 70 The photostability of composites was also analyzed by continuously irradiating the films with UV−vis light for 40 min (Figures S35 and S36). TNB emitted red light at λ em 660 nm and λ em 630 nm in the solid state and polymer composite, respectively.…”

A systematic review of trends in photobiomodulation in dentistry between 2018 and 2022: advances and investigative agenda

“… 35 Additionally, these studies identify that irradiation strategies employing red LEDs proved to be effective in reducing concentrations of nitric oxide (NO) and reactive oxygen species (ROS), while also stimulating the viability of human dental pulp fibroblasts exposed to lipopolysaccharides. 36 …”

“…35 Additionally, these studies identify that irradiation strategies employing red LEDs proved to be effective in reducing concentrations of nitric oxide (NO) and reactive oxygen species (ROS), while also stimulating the viability of human dental pulp fibroblasts exposed to lipopolysaccharides. 36 Citations per author This indicator gauges the impact authors have made by considering the number of citations linked to their research work. Figure 6 showcases the top ten authors with the highest number of citations in the research field.…”