Facial Nerve Nanoengineering and Regeneration

Facial nerve injury can cause severe physical and psychological morbidity and may require multiple reconstructive procedures with limited dynamic return. Prior synthetic neural grafts lacked nanostructural organization and have been limited by inefficient neural regrowth, disordered myelin sheaths, scar infiltration and poor mechanical support. HYPOTHESIS: Resorbable peptide nanofibers within a biodegradable PLGA conduit provide the nanostructure necessary to guide organized and functional neural regeneration more rapidly and with better return of function than the current clinical gold standards of autografting or reanimation surgeries. RESEARCH DESIGN: Adult rats will undergo a unilateral facial nerve transection followed by 1) immediate and 2) delayed end-end anastomosis of the nanofiber neural graft, 3) proximal anastomosis of the neural graft with direct anchoring to distal musculature, 4) cross-facial anastomosis with the resected buccal or marginal mandibular facial nerve branch serving as an autograft, 5) cross-facial anastomosis with the nanofiber neural graft, 6) or no intervention. The intact contralateral facial nerve in groups 1-3 & 6 will serve as control. METHODS: All nerve grafting will be performed according to clinically relevant microsurgical techniques. Nerve function and regeneration will be assessed with electromyography, direct nerve stimulation, transmission electron microscopy (TEM), and immunohistochemistry at 0, 8 and 16 weeks. MEASURES OF SUCCESS: This study will provide a quantitative electrophysiologic, histological and structural evaluation of this novel nanofiber neurograft for the acutely and chronically injured facial nerve injury and compare to the clinical gold-standard of autografting. SIGNIFICANCE: A novel, resorbable nano-engineered graft for facial nerve injury could significantly improve quality of life for patients with facial paralysis and possibly lead to new treatments for other forms of neural injury.