Engineered Graphene Material Improves the Performance of Intraneural Peripheral Nerve Electrodes

• Published in: Advanced science Vol. 11; no. 29; pp. e2308689 - n/a
• Main Authors: Rodríguez‐Meana, Bruno, Valle, Jaume, Viana, Damià, Walston, Steven T., Ria, Nicola, Masvidal‐Codina, Eduard, Garrido, Jose A., Navarro, Xavier
• Format: Journal Article
• Language: English
• Published: Germany John Wiley & Sons, Inc 01.08.2024; John Wiley and Sons Inc; Wiley
• Subjects: Action Potentials - physiology; Animals; Biocompatibility; Biocompatible Materials; Carbon; Electrodes; Electrodes, Implanted; foreign body reaction; Graphene; Graphite - chemistry; Interfaces; intraneural electrode; Male; Microelectrodes; Nervous system; Neurons; neuroprostheses; Peripheral Nerves - physiology; Rats; recording; stimulation; Transplants & implants; recording; intraneural electrode; neuroprostheses; graphene; foreign body reaction; stimulation
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202308689

Limb neuroprostheses aim to restore motor and sensory functions in amputated or severely nerve‐injured patients. These devices use neural interfaces to record and stimulate nerve action potentials, creating a bidirectional connection with the nervous system. Most neural interfaces are based on standard metal microelectrodes. In this work, a new generation of neural interfaces which replaces metals with engineered graphene, called EGNITE, is tested. In vitro and in vivo experiments are conducted to assess EGNITE biocompatibility. In vitro tests show that EGNITE does not impact cell viability. In vivo, no significant functional decrease or harmful effects are observed. Furthermore, the foreign body reaction to the intraneural implant is similar compared to other materials previously used in neural interfaces. Regarding functionality, EGNITE devices are able to stimulate nerve fascicles, during two months of implant, producing selective muscle activation with about three times less current compared to larger microelectrodes of standard materials. CNAP elicited by electrical stimuli and ENG evoked by mechanical stimuli are recorded with high resolution but are more affected by decreased functionality over time. This work constitutes further proof that graphene‐derived materials, and specifically EGNITE, is a promising conductive material of neural electrodes for advanced neuroprostheses. EGNITE is a newly graphene‐based material developed for interfacing the nervous system. Histological and functional analyses revealed that the EGNITE integrated properly into the peripheral nerve. EGNITE stimulation and recording capabilities overperformed those of other conductive materials commonly used in neural electrodes.