Synergistic Effect of Polydeoxyribonucleotides with Low-Level Lasers on the Regeneration of Crush-Injured Facial Nerves

<b>Background/Objectives</b>: The regeneration of the facial nerve using low-level laser therapy (LLLT) has been infrequently reported. Polydeoxyribonucleotides (PDRNs), a blend of short deoxyribonucleotide polymers known for their non-toxic and non-allergic properties, are recognized as a stimulator of cell growth that enhances cell proliferation and supports wound healing. This study investigates the synergistic effect of the topical sustained release of PDRN/F-127 and LLLT on facial nerve regeneration following crush injury-induced paralysis in rats. <b>Methods</b>: The main trunk of the facial nerve was compressed for 1 min using a hemostat. Animals were divided into five groups: a control group (n = 4), group I (Pluronic F-127 only, n = 4), group II (Pluronic F-127/PDRN, n = 4), group III (Pluronic F-127 + LLLT, n = 4), and group IV (Pluronic F-127/PDRN + LLLT, n = 4). We measured the recovery of vibrissa fibrillation, action potential, and facial nerve blood flow (FNBF). <b>Results</b>: Group IV exhibited a comparatively faster development of vibrissa fibrillation over time than the other groups. After the intervention, significant differences in vibrissa fibrillation values were observed at all time points (<i>p</i> = 0.0028) according to the repeated one-way ANOVA. Regarding the threshold of action potential, all five groups revealed a significant difference (one-way ANOVA, <i>p</i> < 0.0001; multiple comparisons via Tukey's test). Among the groups, group IV showed a significantly reduced threshold of action potential compared to the other groups. Group IV showed the most notable recovery in FNBF compared to the other groups. One-way ANOVA showed a significant difference (<i>p</i> < 0.0001; multiple comparisons by Dunnett's test). <b>Conclusions</b>: These findings suggest that PDRN and LLLT may work together synergistically to enhance peripheral nerve regeneration. Future studies should investigate the underlying molecular mechanisms and evaluate the potential clinical applications of this combined treatment strategy.