Promoting and Orienting Axon Extension Using Scaffold-Free Dental Pulp Stem Cell Sheets

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Neuroscience

Background:

• Facial nerve injuries often lead to poor functional outcomes due to limited axon regeneration and incorrect reinnervation.
• Current treatments struggle to effectively address these challenges, necessitating novel therapeutic approaches.

Purpose of the Study:

• To engineer bioactive, scaffold-free cell sheets using dental pulp stem/progenitor cells (DPCs) and their aligned extracellular matrix (ECM) to improve facial nerve regeneration.
• To investigate the neurotrophic factor production and neuritogenic effects of aligned DPC sheets.
• To assess the potential of these aligned DPC sheets as a therapeutic strategy for facial nerve repair.

Main Methods:

• Human DPCs were cultured on microgrooved substrates to induce cellular and ECM alignment.
• The production of neurotrophic factors (NTFs) by aligned and unaligned DPC sheets was quantified.
• The effect of aligned DPC sheets on neurite outgrowth and orientation in neuron-like cells was evaluated *in vitro*.

Main Results:

• Aligned DPC sheets were successfully generated and demonstrated robustness.
• Aligned DPC sheets exhibited increased expression of select NTFs compared to unaligned controls.
• Aligned DPC sheets significantly enhanced neurite orientation and reduced branching in neuron-like cells *in vitro*.

Conclusions:

• Linearly aligned DPC sheets can biomechanically support axon regeneration and improve axonal guidance.
• These aligned DPC sheets hold promise for enhancing facial nerve recovery, potentially used with nerve conduits or as stand-alone conduits.