Photobiomodulation With 976 nm Diode Laser Enhances Osteoblastic Differentiation of Saos‐2 Cells Cultured on Collagen Membranes

OBJECTIVE: Laser photobiomodulation (PBM) influences cellular proliferation, morphology, and differentiation. Collagen membranes provide a bioactive scaffold that supports osteoblastic behavior; however, the effects of PBM on preosteoblastic Saos-2 cells cultured on these membranes remain unclear. This study aimed to evaluate the impact of PBM on the proliferation, morphology, and differentiation of Saos-2 cells grown on collagen membranes. MATERIAL AND METHODS: Saos-2 cells were cultured either on collagen membranes (Jason, Straumann) or directly on plates. Experimental groups included: Control (Saos-2), Saos-2+ Jason, Saos-2+Jason+Laser (976 nm diode), Saos-2+Laser, and Saos-2+Jason+ODM (osteogenic differentiation medium). Cell proliferation was assessed with the resazurin assay on days 2, 5, and 7. Morphology was analyzed by scanning electron microscopy (SEM). Reactive oxygen species (ROS) were quantified using DCFH-DA, ATP production by luminescence assay, and osteogenic markers (RUNX2 and BMP2) by RT-qPCR. RESULTS: PBM reduced proliferation in Saos-2+Jason+Laser cells (49.5% on day 2) without affecting viability, suggesting differentiation rather than cytotoxicity. SEM revealed increased cell size and membrane blebbing in irradiated membrane cultures, whereas non-irradiated cells showed fewer extensions. PBM significantly upregulated RUNX2 and BMP2 expression on day 7, accompanied by elevated ROS and ATP levels, indicating enhanced metabolic activity and osteogenic induction in the Saos-2+Jason+Laser group. CONCLUSIONS: PBM with a 976 nm diode laser induces significant cellular responses in Saos-2 cells, characterized by reduced proliferation and enhanced osteoblastic differentiation, particularly when cultured on collagen membranes. These effects appear to be mediated by elevated ROS and ATP levels and by morphological characteristics consistent with differentiation. The findings highlight the potential of PBM as an adjunctive strategy for bone tissue regeneration and its promising application in regenerative dentistry, especially in combination with biomaterials such as collagen membranes.