Approximately 300,000 Americans suffer from spinal cord injuries (SCI) and nearly 20 million suffer from peripheral nerve injuries. Full recovery from these conditions has historically been an unlikely prospect, with drug therapy and surgical approaches to both having shown only limited success because of their inability to prevent long-term progression of conditions -- in the case of SCI -- and the various complications that stem from relying on nerve grafts -- in the case of peripheral nervous system treatment.
Neural tissue engineering and drug delivery through electrospun scaffolds has emerged as a promising advancement in the areas of spinal and peripheral nerve repair, with implanted scaffolds showing improved cell regeneration compared to traditional treatment methods.
Researchers at the University of Zurich have developed an implantable fibrin-based hydrogel capable of long-term drug release as a potential treatment for spinal cord injury. Applications of the hydrogels in spinal cord lesion models resulted in nerve fiber regeneration and improved overall neural fiber density. Notably however, assessments of behavioral improvement were not performed following the neural fiber regeneration, creating difficulties in assessing the functional improvements that this treatment could facilitate.
Electrospinning-based treatments have also created advancements in the regeneration of peripheral nerve fibers. Compared to traditional lack of regenerative capabilities in the spinal cord neural fibers, peripheral neural fibers exhibit a tremendous ability to regrow following traumatic injury. However, if the distance between the proximal and distal segments of the injured nerve is too great, microsurgical procedures are required to graft a new nerve section into the gap. This procedure suffers from a variety of limitations, most notably mismatches in size of the grafted nerve segment and the recipient site have the potential to result in complications, including a lack of functionality. By functionalizing polycaprolactone-based (PCL) electrospun scaffolds with glycosaminoglycans (GAGs) -- a type of polysaccharide involved in nerve fiber proliferation -- neurological researchers at the Washington University School of Medicine have observed novel improvements in the proliferation and differentiation of Schwann cells within nerve fibers. The use of these scaffolds offers a promising potential for the advancement of peripheral nerve trauma treatment through the improved nerve regeneration capabilities it offers.
Electrospinning shows promising potential to advance the traditionally challenging areas of spinal cord and peripheral nerve injury treatment through the technology’s applications in tissue engineering and drug delivery.
Idini, M., Wieringa, P., Rocchiccioli, S., Nieddu, G., Ucciferri, N., Formato, M., Lepedda, A., & Moroni, L. (2019). Glycosaminoglycan functionalization of electrospun scaffolds enhances Schwann Cell activity. Acta Biomaterialia, 96, 188–202. https://doi.org/10.1016/j.actbio.2019.06.054
Nance, E., Pun, S.H., Saigal, R. et al. Drug delivery to the central nervous system. Nat Rev Mater 7, 314–331 (2022). https://doi.org/10.1038/s41578-021-00394-w
Taylor, S. J., McDonald, J. W., & Sakiyama-Elbert, S. E. (2004). Controlled release of
neurotrophin-3 from fibrin gels for Spinal Cord Injury. Journal of Controlled
Release, 98(2), 281–294. https://doi.org/10.1016/j.jconrel.2004.05.003