Photobiomodulation Modulates the Response of Zoledronic-Acid-Treated Osteoblast-like SaOs-2 Cells: Implications for Bisphosphonate-Related Osteonecrosis

This study aimed to evaluate the effects of laser photobiomodulation (PBM) therapy in SaOs-2 osteosarcoma cells treated with zoledronic acid (ZA), a bisphosphonate, in vitro, mimicking a bisphosphonate-related osteonecrosis of the jaw (BRONJ) situation. Cells were treated with 100 μM ZA for 24 h and subjected to PBM using wavelengths of 660 nm and 808 nm at energy delivered of 1, 5, 10, and 20 J. After 24 h, metabolic activity, apoptosis, and BAX and BCL-2 gene expression were analyzed. Data were compared using one-way ANOVA followed by Tukey's post hoc test (<i>p</i> < 0.05). ZA significantly reduced metabolic activity (<i>p</i> < 0.05), an effect attenuated by PBM at 808 nm with 1 J, while BCL-2 expression increased with 1 J at 660 nm and with 1 J and 20 J at 808 nm. However, PBM did not reverse ZA-induced apoptosis. In conclusion, PBM modulated the response of SaOs-2 osteoblastic cells treated with ZA in a wavelength- and dose-dependent manner. PBM at 808 nm and 1 J stimulated cell metabolic activity and upregulated BCL-2 expression, suggesting a potential protective effect against ZA-induced cytotoxicity.