Department of Orthodontics, Faculty of Dentistry, Mahidol University, Bangkok, Thailand.
Department of Orthodontics, Faculty of Dentistry, Mahidol University, Bangkok, Thailand.
J World Fed Orthod. 2021 Jun;10(2):79-85. doi: 10.1016/j.ejwf.2021.03.003. Epub 2021 Apr 20.
The aim of this study was to investigate the influence of three different light-emitting diode (LED) wavelengths on the proliferation and osteoblastic differentiation of periodontal ligament stem cells (PDLSCs) in vitro.
PDLSCs seeded on 96- and 24-well plates, for proliferation and osteoblastic differentiation, respectively, were irradiated daily by LED light with peak emission wavelengths of 630, 680, and 830 nm at constant energy densities of 3.5 J/cm. Cultures were grown for 8 days for the proliferation assay, 10 days for the alkaline phosphatase (ALP) assay, and 28 days for Alizarin red staining. Mitochondrial activity, ALP enzyme level, and the ability to form calcium phosphate deposits were measured and compared across cultures.
Results obtained from statistical analysis of the experimental data indicated that the rate of proliferation (P < 0.05) in 830-nm irradiated cultures were significantly higher than the control samples at day 6 and 8; whereas, for the 630- and 680-nm groups, test results showed lower proliferation rates at day 8. For osteoblastic differentiation, significantly greater mineralization than the control samples was detected in the red-light groups (630 and 680 nm) during the late differentiation period (P < 0.001), which was supported by a higher ALP activity of the 630- and 680-nm groups in the early stage (P < 0.01).
The results of this study demonstrate that the PDLSCs responded differently to specific LED wavelengths. For enhancing cellular proliferation, 830-nm LED irradiation was more effective. On the other hand, the wavelengths of 630 and 680 nm were better for stimulating osteoblastic differentiation.
本研究旨在探讨三种不同发光二极管（LED）波长对体外牙周膜干细胞（PDLSCs）增殖和成骨分化的影响。
将 PDLSCs 接种于 96 孔和 24 孔板中，分别用于增殖和成骨分化实验，用峰值发射波长为 630、680 和 830nm 的 LED 光每日辐照，恒定能量密度为 3.5J/cm。增殖实验培养 8 天，碱性磷酸酶（ALP）实验培养 10 天，茜素红染色实验培养 28 天。测量和比较各培养物的线粒体活性、ALP 酶水平和形成钙磷沉积物的能力。
对实验数据的统计分析结果表明，在第 6 天和第 8 天，830nm 辐照培养物的增殖率（P<0.05）明显高于对照组；而 630nm 和 680nm 组的增殖率则在第 8 天较低。对于成骨分化，在晚期分化阶段，红光大组（630nm 和 680nm）的矿化程度明显高于对照组（P<0.001），而在早期阶段，630nm 和 680nm 组的 ALP 活性更高（P<0.01）。
本研究结果表明，PDLSCs 对特定 LED 波长的反应不同。为了增强细胞增殖，830nm LED 照射更有效。另一方面，630nm 和 680nm 波长更有利于刺激成骨分化。
