Oral mucosa cues for regeneration using Photobiomodulation

Photobiomodulation therapy (PBMT) is gaining recognition as an effective method for repairing damaged tissues, particularly in skin and mucosa injuries. Despite its growing use, there remains a significant gap in understanding the interaction of ectomesenchymal components during light therapy. This study explored various near-infrared light parameters on stressed skin keratinocytes (KC) cultured alone or in association with oral fibroblasts (FB) using a transwell system. Reactive oxygen species (ROS) levels were quantified, alongside observations of cell viability/proliferation, migration, and pro-resolutive gene expression in KC cultivated conventionally (at 1, 5, and 50 J/cm²; 1.4, 7 and, 70 s; 0.03, 0.14, and 1.4 J, respectively; 0.71 W/cm²; 20 mW) and co-cultured with FB (at 5 J/cm²). Murine tongue fragments were also treated at 5 J/cm² for three days. The results revealed increased ROS levels in stressed cells. PBMT enhanced cell viability/proliferation and migration of KC in vitro, while pro-inflammatory cytokines were predominantly suppressed following irradiation. All energy densities and culture models showed upregulation of amphiregulin. In the co-culture system, PBMT notably upregulated interleukin 1 - receptor antagonist and vascular endothelial growth factor genes while downregulating transforming growth factor-β1 expression. In ex vivo tongue fragments, PBMT significantly increased lamina propria thickness and spindle-shaped cell counts compared to non-irradiated samples. Overall, near-infrared PBMT demonstrated pro-regenerative effects by modulating inflammation. The activation of pro-resolutive molecules and the dampening of cytokines may favor early tissue remodeling in the dermis counterpart.