Microchannel-based regenerative scaffold for chronic peripheral nerve interfacing in amputees

Area of Science:

• Biomaterials Science
• Neuroscience
• Regenerative Medicine

Background:

• Current neural prosthetics offer limited functionality compared to natural limbs.
• A clinical need exists for improved prosthetic devices that mimic amputated limbs.
• Peripheral nerve regeneration requires suitable guidance and interfaces.

Purpose of the Study:

• To fabricate and evaluate polydimethylsiloxane (PDMS) and SU-8 microchannel scaffolds for peripheral nerve interfacing.
• To assess the capacity of microchannels to support and direct nerve regeneration in an amputee model.
• To investigate the potential for these scaffolds to enable stable, chronic neural interfaces.

Main Methods:

• Fabrication of PDMS and SU-8 microchannel scaffolds with 100 μm × 100 μm cross-sections.
• In vitro and in vivo studies using a sciatic nerve amputee model.
• Chronic in vivo electrophysiology with integrated microwire electrodes to assess interfacing capabilities.

Main Results:

• Microchannels successfully supported and directed the regeneration of axons, Schwann cells, and fibroblasts.
• Organized nerve regeneration, including fascicle formation and myelination, was observed distal to the scaffold.
• No aberrant nerve growth (neuroma formation) was detected.
• Spontaneous, sensory-evoked, and electrically-evoked action potentials were recorded for up to five months post-implantation.

Conclusions:

• Microchannel scaffolds promote organized peripheral nerve regeneration and are suitable for chronic implantation.
• These scaffolds facilitate stable neural interfaces, crucial for advanced prosthetic development.
• The study provides a foundation for creating large-electrode count, wireless microchannel devices for bi-directional neural interfaces.