Decellularized grafts with axially aligned channels for peripheral nerve regeneration

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Peripheral nerve injuries (PNI) affect millions globally, with autografts being the gold standard but having significant drawbacks.
• Decellularized nerve allografts offer an alternative but require improvements in cell penetration due to small pore sizes (5-10μm).
• Current strategies involve adding growth factors and cells, but physical scaffold modifications are needed for better axonal guidance.

Purpose of the Study:

• To optimize decellularization methods for enhanced cellular removal while preserving nerve matrix structure.
• To engineer axially aligned channels in decellularized nerve grafts using a novel unidirectional freeze-drying technique.
• To evaluate the mechanical properties and cell penetration capabilities of the modified decellularized nerve grafts.

Main Methods:

• Modified an existing decellularization protocol for rat sciatic nerve sections.
• Employed standard and unidirectional freeze-drying techniques to create specific pore architectures.
• Assessed scaffold mechanical properties and quantified cell penetration after 14 days of in vitro culture.

Main Results:

• Unidirectional freeze-drying successfully created axially aligned channels (approx. 20-60μm diameter) in decellularized nerve grafts.
• The unidirectional freeze-dried scaffolds exhibited mechanical tensile properties comparable to native nerve tissue.
• Significantly enhanced cellular penetration was observed in scaffolds with aligned channels compared to controls.

Conclusions:

• Unidirectional freeze-drying is a viable method for fabricating decellularized nerve grafts with aligned, porous architectures.
• The engineered aligned channels facilitate enhanced cell infiltration, crucial for peripheral nerve regeneration.
• This approach represents a novel strategy for improving decellularized allografts for future peripheral nerve repair applications.