Division of Oral Pathology, Faculdade São Leopoldo Mandic, Rua José Rocha Junqueira 13, Swift, Campinas, SP, 13045-755, Brazil.
School of Dentistry, University of Ribeirao Preto, Avenida Costábile Romano, 2201, Nova Ribeirânia, Ribeirão Preto, SP, 14096-900, Brazil.
Photochem Photobiol Sci. 2024 Aug;23(8):1565-1571. doi: 10.1007/s43630-024-00616-4. Epub 2024 Jul 26.
The present study aimed to evaluate the effect of photobiomodulation therapy (PBM) on different stages of osteogenesis in vitro. For this, osteoblastic-like cells (Saos-2 cell lineage) were irradiated in two different periods: during the Proliferation phase (PP; from the second to the fourth day) and during the Differentiation phase (DP; from the seventh to the ninth day). The energy density used in the study was 1.5 J/ cm. The following parameters were evaluated: 1) quantification of collagen type 1 (COL 1), osteopontin (OPN), and bone morphogenetic protein 2 (BMP-2); 2) quantification of alkaline phosphatase (ALP) activity; and 3) quantification of extracellular matrix (ECM) mineralization. Non-irradiated cultures were used as controls. The data were analyzed using the Student's t-test or one-way ANOVA, considering a significance level of 5%. The results indicated that COL 1 and BMP-2 quantification was higher in Saos-2 irradiated during the DP in relation to the control group at day 10 (p < 0.05). No differences were observed for other comparisons at this time point (p > 0.05). OPN expression was greater in PP compared with the other experimental groups at day 10 (p < 0.05). Irradiation did not affect ALP activity in Saos-2 regardless of the exposure phase and the time point evaluated (p > 0.05). At day 14, ECM mineralization was higher in Saos-2 cultures irradiated during the DP in relation to the PP (p < 0.05). In conclusion, the results suggested that the effects of PBM on osteoblastic cells may be influenced by the stage of cell differentiation.
本研究旨在评估光生物调节疗法（PBM）对体外成骨不同阶段的影响。为此，用两种不同时期对成骨细胞样细胞（Saos-2 细胞系）进行辐照：增殖期（PP；第 2 天至第 4 天）和分化期（DP；第 7 天至第 9 天）。研究中使用的能量密度为 1.5 J/cm。评估了以下参数：1）胶原 1（COL 1）、骨桥蛋白（OPN）和骨形态发生蛋白 2（BMP-2）的定量；2）碱性磷酸酶（ALP）活性的定量；3）细胞外基质（ECM）矿化的定量。未辐照的培养物用作对照。使用学生 t 检验或单因素方差分析对数据进行分析，置信水平为 5%。结果表明，与对照组相比，Saos-2 在 DP 期间辐照的 COL 1 和 BMP-2 定量在第 10 天更高（p<0.05）。在该时间点，其他比较没有差异（p>0.05）。与其他实验组相比，OPN 表达在第 10 天的 PP 中更高（p<0.05）。无论暴露阶段和评估时间点如何，辐照均未影响 Saos-2 中的 ALP 活性（p>0.05）。在第 14 天，Saos-2 培养物中 DP 期间辐照的 ECM 矿化高于 PP（p<0.05）。总之，结果表明，PBM 对成骨细胞的影响可能受细胞分化阶段的影响。
