Dual near-infrared wavelength photobiomodulation accelerates transdermal burn wound repair via anti-inflammatory, pain relief and redox-regulating mechanisms

Abstract

Burns cause severe tissue damage and impose a significant psychological and financial burden, highlighting the need for innovative, effective, and cost-efficient therapeutic interventions for tissue repair. Research indicates that multimodal therapy enhances healing by positively regulating various phases of tissue repair. Photobiomodulation therapy (PBMT), which employs low-power light, offers a promising non-pharmacological energy-based healing approach for non-healing wounds. Absorbed photons stimulate cellular metabolism, increase ATP production, and modulate molecular signaling pathways, thereby facilitating the repair process. In this study, we investigated the effects of combined NIR pulsed 810 nm and superpulsed 904 nm lasers PBMT on inflammation, pain, and redox status during transdermal burn wound healing in rats. Animals were divided into five groups, namely uninjured, control (burn), pulsed 810 nm, superpulsed 904 nm lasers, and dual wavelength PBMT. Combined PBMT exhibited a positive synergistic effect on the burn repair process by significantly (P < 0.05) reducing inflammation (NF-κB, TNF-α, IL-1β, NOS-2, IL-6), pain (substance P-receptor, COX-2), and oxidative stress (ROS, 4-HNE adduct, LPO, 3-NT), while increasing redox potential/endogenous antioxidant (Nrf2, catalase), and maintaining cytoprotection (GRP78) seven days post-wounding. These molecular findings were well-supported by histopathological analysis, which indicated decreased mast cell infiltration, exhibiting the potent anti-inflammatory effects of the combined PBMT. Altogether, the current findings demonstrate that dual PBMT synergistically accelerates the repair of full-thickness burns, exhibits analgesic, anti-inflammatory responses, reduces oxidative stress, activates the antioxidant defense pathway, and maintains cellular redox homeostasis. This non-invasive dual NIR PBMT presents a promising translational therapeutic approach for burn repair in clinical care.