Bölükbaşı Ateş Gamze, Ak Can Ayşe, Gülsoy Murat
Institute of Biomedical Engineering, Bogazici University, Uskudar, Istanbul, Turkey, 34684.
Engineering Faculty, Biomedical Engineering, Erzincan University, Erzincan, Turkey, 24100.
Lasers Med Sci. 2017 Apr;32(3):591-599. doi: 10.1007/s10103-017-2153-6. Epub 2017 Jan 23.
Photobiomodulation (PBM) describes light-induced photochemical reactions achieved by the application of red or near infrared lasers/LED light with low energy densities. This noninvasive and painless method has been used in some clinical areas but controversial outcomes demand a skeptical look for its promising and potential effects. In this detailed in vitro study, the osteoblast cells were irradiated with 635 and 809 nm diode lasers at energy densities of 0.5, 1, and 2 J/cm. Cell viability, proliferation, bone formation, and osteoblast differentiation were evaluated by methylthiazole tetrazolium (MTT) assay, Alamar Blue assay, acridine orange/propidium iodide staining, alkaline phosphatase (ALP) activity, Alizarin red staining, and reverse-transcription polymerase chain reaction (RT-PCR) to test the expression of collagen type I, ALPL, and osteocalcin. The results indicate that studied energy doses have a transient effect (48 h after laser irradiation) on the osteoblast viability and proliferation. Similarly, laser irradiation did not appear to have any effect on ALP activity. These results were confirmed by RT-PCR analysis of osteoblast markers. This study suggests that several irradiation parameters and variations in the methods should be clearly established in the laboratory before laser treatment becomes a postulated application for bone tissue regeneration in clinical level.
光生物调节作用（PBM）是指通过应用低能量密度的红色或近红外激光/发光二极管（LED）光引发的光化学反应。这种无创且无痛的方法已在一些临床领域得到应用，但有争议的结果使其潜在的显著效果受到质疑。在这项详细的体外研究中，用能量密度为0.5、1和2 J/cm的635和809 nm二极管激光照射成骨细胞。通过噻唑蓝（MTT）法、alamar蓝法、吖啶橙/碘化丙啶染色、碱性磷酸酶（ALP）活性检测、茜素红染色以及逆转录聚合酶链反应（RT-PCR）来评估细胞活力、增殖、骨形成和成骨细胞分化，以检测I型胶原蛋白、ALPL和骨钙素的表达。结果表明，所研究的能量剂量对成骨细胞活力和增殖有短暂影响（激光照射后48小时）。同样，激光照射似乎对ALP活性没有任何影响。成骨细胞标志物的RT-PCR分析证实了这些结果。这项研究表明，在激光治疗成为临床水平骨组织再生的假定应用之前，应在实验室中明确确定几个照射参数和方法的差异。
