Department of Pediatric Dentistry, School of Dentistry, Federal University of Uberlândia, UFU, Av. Pará 1720, Umuarama, Uberlândia, MG, 38400902, Brazil.
Department of Oral Pathology, University of Ribeirão Preto, UNAERP, Ribeirão Preto, SP, Brazil.
Lasers Med Sci. 2022 Feb;37(1):607-617. doi: 10.1007/s10103-021-03309-x. Epub 2021 Apr 7.
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 and 0.08 W/cm) at 0 J/cm (control group), 4 J/cm, 15 J/cm, and 30 J/cm; 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 and 30 J/cm at 0.04 W/cm and 4 J/cm and 15 J/cm at 0.08 W/cm (p < 0.05). Exposure to 4 J/cm at 0.04 W/cm and 15 J/cm and 30 J/cm at 0.08 W/cm 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 and 30 J/cm at 0.04 W/cm and 15 J/cm at 0.08 W/cm were the best parameters to decrease NO and ROS concentration and to stimulate viability of HDPFs exposed to LPS challenge.
本研究旨在评估不同辐照参数下红光发光二极管（LED）对人牙髓成纤维细胞（HDPF）氧化应激的调节能力。将乳牙来源的细胞（100,000 个细胞/孔）接种于 24 孔板中的培养基（DMEM）中。孵育 24 小时后，用含 10μg/ml 脂多糖（LPS）的 DMEM 替换培养基。此后，将细胞用红光（LED630nm，0.04W/cm 和 0.08W/cm）照射，剂量分别为 0J/cm（对照组）、4J/cm、15J/cm 和 30J/cm；并通过 MTT 测定法评估细胞活力、台盼蓝计数、一氧化氮（NO）合成（Griess 试剂）和活性氧（ROS）（荧光探针，DCFH-DA）。采用 Kruskal-Wallis 和 Mann-Whitney 检验（用 Bonferroni 校正）进行统计分析（显著性水平为 5%）。与对照组相比，LPS 处理的 HDPF 经 15J/cm 和 30J/cm（0.04W/cm）和 4J/cm 和 15J/cm（0.08W/cm）照射后，活力增加（p<0.05）。与未辐照 LPS 处理的牙髓细胞相比，4J/cm（0.04W/cm）和 15J/cm 以及 30J/cm（0.08W/cm）辐照调节了细胞的氧化应激（p<0.05）。结论：使用辐射剂量为 15J/cm 和 30J/cm（0.04W/cm）和 15J/cm（0.08W/cm）的红光 LED 照射策略是降低 LPS 刺激的 HDPF 中 NO 和 ROS 浓度并刺激其活力的最佳参数。
