Functional Recovery of Carbon Nanotube/Nafion Nanocomposite in Rat Model of Spinal Cord Injury

Abstract

Background

Acute spinal cord injury (ASCI) can lead to paraplegia or quadriplegia, the treatment of which has been a major problem. New therapeutic approaches in developing carbon nanotubes (CNT) functionalized with the Nafion nanocomposite, a sulfonated tetrafluoroethylene copolymer, have been shown to increase the length of selected neurites in vitro.

Objective

We hypothesized that the administration of the CNT/Nafion nanocomposite after experimental SCI will promote regeneration of axons into the lesion cavity and the functional recovery of the hind limbs in a rat model.

Methods

To evaluate this hypothesis through this experimental research paper, transection SCI was induced at the T9-T10 vertebral level in adult female rats. One week after transection, the epicenter of the lesion was injected with 25 lL of vehicle (saline), or 1 lg/mL, 10 lg/mL, or 100 lg/mL of CNT/Nafion nanocomposite. Behavioral analysis was carried out by assessing tail flick, chronic pain or mechanical allodynia, motor coordination, and the results of the rotarod test performed pre- and post-surgery, on days 3, 7, 14, 21 and 28, using the tail flick analysis, Noldus CatWalk gait analysis, open-field locomotor test, and Rotarod test. At 28 days post-injection, the rats were euthanized and spinal cord tissue was extracted.

Results

We found that post-SCI, administration of the CNT/Nafion nanocomposite resulted in decreased lesion volume, increased neurofilament-positive fibers and corticospinal tract fibers in the lesion, and no increase in reactive gliosis (P < 0.001). Additionally, post-SCI administration of CNT/Nafion nanocomposite induced a modest improvement in hind limb locomotor recovery without inducing hyperalgesia.

Conclusion

These data suggest that the CNT/Nafion nanocomposite may be an effective material to promote axonal repair and regeneration after SCI.

Keywords::

• carbon nanotubes
• functional recovery
• Nafion
• Spinal cord injury

Acknowledgments

The authors greatly appreciate the financial support from Payame Noor University and Yazd University for conduction the present project.

Authors’ contributions

SRZ and SI designed and synthesized the nanocomposite, guided the contact angle analysis, and prepared the manuscript. SRZ participated in the SEM and TEM analysis and prepared the manuscript. ZZ and FL facilitated and enabled the animal studies and the SCI. All authors read and approved the final manuscript.

Funding

This research received no specific grant from any funding agency from the public, commercial, or not-for-profit sectors.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.