Synergistic Enhancement of Facial Nerve Regeneration Using a Cellulose-Based Nerve Conduit Loaded with Mesenchymal Stem Cells and Human Placental Extract

Background: Facial nerve regeneration across segmental defects remains challenging despite advances in nerve guidance conduits. Tissue engineering strategies that combine biomaterial scaffolds with bioactive and cellular components may enhance functional and structural nerve repair. This study investigated the regenerative efficacy of a cellulose-based nerve conduit augmented with Matrigel, mesenchymal stem cells (MSCs), and placental extract (PE) in a rat facial nerve gap model. Methods: A 2 mm defect was created at the main trunk of the facial nerve in adult Sprague–Dawley rats. Animals were divided into three groups: control group (Cellulose/Matrigel), group I (Cellulose/Matrigel/MSC), and group II (Cellulose/Matrigel/MSC/PE). Functional recovery was assessed at 2, 4, 6, and 8 weeks postoperatively using slow-motion vibrissa movement analysis, electrically stimulated facial nerve action potential measurements, and facial nerve blood flow by laser Doppler blood flow analysis. Morphological regeneration was evaluated using light microscopy and transmission electron microscopy. Western blotting using facial muscle was performed. Results: All groups exhibited time-dependent facial nerve regeneration. However, group II demonstrated significantly enhanced functional recovery, greater electrophysiological responses, increased nerve blood flow, and superior histological and ultrastructural regeneration compared with the other groups. These improvements were particularly prominent at 6 and 8 weeks postoperatively. Conclusions: The combination of mesenchymal stem cells and PE within a cellulose-based nerve conduit synergistically enhanced facial nerve regeneration. This tissue-engineered strategy may represent an effective approach for improving peripheral nerve repair.