Ultraconformable cuff implants for long-term bidirectional interfacing of peripheral nerves at sub-nerve resolutions

Area of Science:

• Biomedical Engineering
• Neuroscience
• Materials Science

Background:

• Implantable peripheral nerve devices face challenges with longevity, resolution, and biocompatibility.
• Poor nerve-electrode interfaces and foreign body reactions limit current applications.

Purpose of the Study:

• To develop conformable cuff implants for high-quality, stable nerve interfacing.
• To enable precise sensing and modulation of nerve activity for research and therapeutics.

Main Methods:

• Chronic implantation of conformable cuff electrodes in rat sensorimotor nerves.
• Recording of nerve action potentials, conduction velocity, and propagation direction.
• Evaluation of biocompatibility and fibrotic scarring compared to silicone cuffs.
• Modulation of nerve activity to elicit paw movements and characterization of C fiber activity in a neuropathic pain model.

Main Results:

• Devices achieved fascicle-specific resolution for nerve signal recording over 21 days.
• High biocompatibility demonstrated with reduced fibrotic scarring versus silicone cuffs.
• Successful modulation of nerve activity for controlled paw movements.
• Identification and characterization of C fiber activity changes in neuropathic pain.

Conclusions:

• The developed cuff implants provide a stable, high-resolution interface for chronic nerve sensing and modulation.
• These devices show promise for advancing physiological research and developing closed-loop therapeutic strategies.
• The platform offers improved biocompatibility and functional capabilities over existing technologies.