Dual-Modality Bioactive Repair of Facial Nerve Injury Using PEG-Mediated Axonal Fusion and Extracellular...

Area of Science:

• Biomaterials Science
• Neuroscience
• Regenerative Medicine

Background:

• Facial nerve injuries often result in significant functional loss with poor outcomes after conventional surgical repair.
• Standard neurorrhaphy techniques have limitations in promoting complete nerve regeneration and functional restoration.

Purpose of the Study:

• To develop and evaluate a dual-modality bioactive repair interface for accelerated neural repair.
• To investigate the combined effects of polyethylene glycol (PEG)-mediated axonal fusion and gingiva-derived mesenchymal stem cell (GMSC) secretome on nerve regeneration.

Main Methods:

• Integration of PEG fusion for immediate axonal reconnection with GMSC secretome for trophic support.
• In vitro assessment of secretome internalization by neurons.
• Ex vivo evaluation of GMSC secretome's effect on axonal structure preservation.
• In vivo testing in a rat facial nerve transection model to assess functional and histological outcomes.

Main Results:

• PEG fusion immediately restored compound muscle action potentials (CMAPs).
• GMSC secretome preserved axonal structure and, with PEG fusion, increased axon density and myelination.
• The combined PEG + secretome treatment demonstrated the highest axon density, axonal area, and organized myelin architecture.
• Combined treatment led to superior functional recovery, indicated by increased CMAP amplitudes at 42 days post-injury.

Conclusions:

• The developed cell-free repair platform effectively couples immediate axonal fusion with trophic signaling.
• This dual-modality approach promotes rapid and durable recovery from cranial and peripheral nerve injuries.
• The findings support the clinical translatability of this strategy for nerve repair.