Stein Elisabeth, Koehn Jadranka, Sutter Walter, Wendtlandt Gabriele, Wanschitz Felix, Thurnher Dietmar, Baghestanian Mehrdad, Turhani Dritan
Department of Cranio-Maxillofacial and Oral Surgery, Medical University of Vienna, Austria.
Wien Klin Wochenschr. 2008;120(3-4):112-7. doi: 10.1007/s00508-008-0932-6.
Low-level laser therapy is a clinically well established tool for enhancement of wound healing. In vitro studies have also shown that low level laser therapy has a biostimulatory effect on cells of different origin. The aim of this in vitro study was to investigate the initial effect of low-level laser therapy on growth and differentiation of human osteoblast-like cells. SaOS-2 cells were irradiated with laser doses of 1 J/cm2 and 2 J/cm2 using a diode laser with 670 nm wave length and an output power of 400 mW. Untreated cells were used as controls. At 24 h, 48 h and 72 h post irradiation, cells were collected and assayed for viability of attached cells and alkaline phosphatase specific activity. In addition, mRNA expression levels of osteopontin and collagen type I were assessed using semi-quantitative RT-PCR. Over the observation period, cell viability, alkaline phosphatase activity and the expression of osteopontin and collagen type I mRNA were slightly enhanced in cells irradiated with 1 J/cm2 compared with untreated control cells. Increasing the laser dose to 2 J/cm2 reduced cell viability during the first 48 h and resulted in persistently lower alkaline phosphatase activity compared with the other two groups. The expression of osteopontin and collagen type I mRNA slightly decreased with time in untreated controls and cells irradiated with 1 J/cm2, but their expression was increased by treatment with 2 J/cm2 after 72 h. These results indicate that low-level laser therapy has a biostimulatory effect on human osteoblast-like cells during the first 72 h after irradiation. Further studies are needed to determine the potential of low-level laser therapy as new treatment concept in bone regeneration.
低强度激光疗法是临床上已得到充分认可的促进伤口愈合的工具。体外研究还表明，低强度激光疗法对不同来源的细胞具有生物刺激作用。本体外研究的目的是调查低强度激光疗法对人成骨样细胞生长和分化的初始影响。使用波长为670 nm、输出功率为400 mW的二极管激光，以1 J/cm²和2 J/cm²的激光剂量照射SaOS-2细胞。未处理的细胞用作对照。在照射后24小时、48小时和72小时，收集细胞并检测贴壁细胞的活力和碱性磷酸酶比活性。此外，使用半定量逆转录聚合酶链反应评估骨桥蛋白和I型胶原的mRNA表达水平。在观察期内，与未处理的对照细胞相比，接受1 J/cm²照射的细胞的细胞活力、碱性磷酸酶活性以及骨桥蛋白和I型胶原mRNA的表达略有增强。将激光剂量增加到2 J/cm²会在最初48小时内降低细胞活力，并导致与其他两组相比碱性磷酸酶活性持续降低。在未处理的对照细胞和接受1 J/cm²照射的细胞中，骨桥蛋白和I型胶原mRNA的表达随时间略有下降，但在72小时后，用2 J/cm²处理会使其表达增加。这些结果表明，低强度激光疗法在照射后的前72小时对人成骨样细胞具有生物刺激作用。需要进一步研究以确定低强度激光疗法作为骨再生新治疗概念的潜力。
