Fernandes Marcella Rodrigues Ueda, Teti Gabriella, Gatta Valentina, Longhin Aurora, Aranha Ana Cecilia Corrêa, Falconi Mirella
Special Laboratory of Lasers in Dentistry (LELO), Department of Dentistry, School of Dentistry, University of São Paulo, Av. Prof. Lineu Prestes 2227, São Paulo 05508-000, Brazil.
Department of Biomedical and Neuromotor Sciences, DIBINEM, University of Bologna, 40100 Bologna, Italy.
Int J Mol Sci. 2025 Aug 22;26(17):8174. doi: 10.3390/ijms26178174.
Photobiomodulation (PBM) consists of applying low-level laser light to biological tissues, leading to modulation of cellular functions. PBM has recently gained much attention in the field of regenerative dentistry thanks to its powerful effect on tissue repair and regeneration. Dental pulp mesenchymal stem/stromal cells (DP-MSCs) represent the ideal targets in regenerative dentistry due to their ability to stimulate the regeneration of mineralized and soft tissues and the paracrine factors that they produce. Although there have been several studies evaluating the influence of PBM on DP-MSCs' regenerative capacity, the results are conflicting, and there are few studies on the influence of PBM on the paracrine factors released by DP-MSCs. Therefore, the aim of this study was to investigate the effect of PBM, using different energy doses of laser irradiation, on the osteogenic capacity of DP-MSCs, focusing on changes in gene expression, mineralizing ability, and release of pro-osteogenic factors. DP-MSCs were irradiated in vitro and differentiated into an osteogenic phenotype. A cell viability assay, alizarin red staining, and TEM analysis were carried out to evaluate the effect of PBM on cell activity, morphology, and mineralization ability. The expression of the main osteogenesis-related markers Runx2, Col1A1, ALP, and BMP was measured to evaluate the influence of PBM on the ability of DP-MSCs to differentiate toward an osteogenic phenotype. The release of IL-6 and IL-8, which are mainly involved in bone remodeling processes, was investigated in the cell medium following PBM irradiation. The results showed a high level of cell viability, suggesting a lack of phototoxicity under the tested conditions. Furthermore, PBM had a significant effect on mineral deposition, IL-6 and IL-8 release, and expression of osteogenic markers. TEM analysis showed intracellular modifications linked mainly to mitochondria, the endoplasmic reticulum, and autophagic vesicles after PBM treatment. These findings demonstrated that the impact of PBM on the osteogenic potential of DP-MSCs is energy dose-dependent, supporting its potential as an effective strategy in regenerative dentistry, particularly for enhancing bone remodeling.
光生物调节作用（PBM）包括将低强度激光照射到生物组织上，从而调节细胞功能。由于其对组织修复和再生具有强大作用，PBM最近在再生牙科领域备受关注。牙髓间充质干细胞（DP-MSCs）因其能够刺激矿化组织和软组织再生以及产生旁分泌因子的能力，成为再生牙科的理想靶点。尽管已有多项研究评估PBM对DP-MSCs再生能力的影响，但结果相互矛盾，且关于PBM对DP-MSCs释放的旁分泌因子影响的研究较少。因此，本研究的目的是研究使用不同能量剂量的激光照射进行PBM对DP-MSCs成骨能力的影响，重点关注基因表达、矿化能力和成骨因子释放的变化。体外照射DP-MSCs并使其分化为成骨表型。进行细胞活力测定、茜素红染色和透射电镜分析，以评估PBM对细胞活性、形态和矿化能力的影响。检测主要成骨相关标志物Runx2、Col1A1、ALP和BMP的表达，以评估PBM对DP-MSCs向成骨表型分化能力的影响。在PBM照射后的细胞培养基中研究主要参与骨重塑过程的IL-6和IL-8的释放。结果显示细胞活力水平较高，表明在测试条件下不存在光毒性。此外，PBM对矿物质沉积、IL-6和IL-8释放以及成骨标志物表达有显著影响。透射电镜分析显示，PBM处理后细胞内的变化主要与线粒体、内质网和自噬小泡有关。这些发现表明，PBM对DP-MSCs成骨潜能的影响是能量剂量依赖性的，支持其作为再生牙科中一种有效策略的潜力，特别是在增强骨重塑方面。
