Carbon-nanotube yarns induce axonal regeneration in peripheral nerve defect

Atsushi Kunisaki,Takeshi Kondo,Masakazu Ishikawa,Akira Kodama,Marcio D Lima,Takahiro Ueda,Nobuo Adachi

doi:10.1038/s41598-021-98603-7

Atsushi Kunisaki, Takeshi Kondo + Show 5 more

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https://doi.org/10.1038/s41598-021-98603-7

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Journal: Scientific Reports	Publication Date: Oct 1, 2021
Citations: 19	License type: open-access

Affiliation: Hiroshima University

Abstract

Carbon nanotubes (CNTs) are cylindrical nanostructures and have unique properties, including flexibility, electrical conductivity, and biocompatibility. We focused on CNTs fabricated with the carbon nanotube yarns (cYarn) as a possible substrate promoting peripheral nerve regeneration with these properties. We bridged a 15 mm rat sciatic nerve defect with five different densities of cYarn. Eight weeks after the surgery, the regenerated axons crossing the CNTs, electromyographical findings, and muscle weight ratio of the lower leg showed recovery of the nerve function by interfacing with cYarn. Furthermore, the sciatic nerve functional index (SFI) at 16 weeks showed improvement in gait function. A 2% CNT density tended to be the most effective for nerve regeneration as measured by both histological axonal regeneration and motor function. We confirmed that CNT yarn promotes peripheral nerve regeneration by using it as a scaffold for repairing nerve defects. Our results support the future clinical application of CNTs for bridging nerve defects as an off-the-shelf material.

Highlights

Carbon nanotubes (CNTs) are cylindrical nanostructures and have unique properties, including flexibility, electrical conductivity, and biocompatibility
This study focused on carbon nanotubes (CNTs) as possible devices to promote peripheral nerve regeneration
Our results indicated that a 2% CNT density tended to be most effective for nerve regeneration as measured by both histological axonal regeneration and motor function

Summary

Introduction

Carbon nanotubes (CNTs) are cylindrical nanostructures and have unique properties, including flexibility, electrical conductivity, and biocompatibility. We focused on CNTs fabricated with the carbon nanotube yarns (cYarn) as a possible substrate promoting peripheral nerve regeneration with these properties. We bridged a 15 mm rat sciatic nerve defect with five different densities of cYarn. Our results support the future clinical application of CNTs for bridging nerve defects as an off-the-shelf material. Clinical results are limited, feature low success rates, and are typically only used for less than 3 cm nerve gaps involving small-diameter, non-critical sensory n erves[5,6]. This study focused on carbon nanotubes (CNTs) as possible devices to promote peripheral nerve regeneration. In terms of nerve regeneration, several studies have shown that CNTs can support sustainable neuronal survival and promote neuronal o utgrowth[10,11,12,13,14]. Aminated CNTs and nerve growth factor (NGF) increase the number of neurons with neurite outgrowth in rat PC12h cell and dorsal root ganglion (DRG) neurons in culture media[15]

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