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Nanostructured scaffolds offer a promising route to repairing spinal cord injuries

February 2, 2011
(Nanowerk Spotlight) Spinal cord injury in humans remains a devastating and incurable disorder. It is still a traumatic pathology that may impair patients' movements by interrupting their motor-sensory pathways. It is estimated that there are approximately 2.5 million people worldwide with a spinal cord injury and over 130,000 people each year survive such a traumatic injury, often bound to spend the rest of their lives in a wheelchair.
Rapid progress in tissue engineering, especially electrospinning techniques that lead to micro- and nanofibrous flexible tubular scaffolds for nerve cell regeneration, may lead to promising therapies for spinal cord injuries.
Researchers in Italy, led by Angelo Vescovi and Fabrizio Gelain, at the CNTE at Niguarda Ca'Granda Hospital, University of Milan-Bicocca and IRCCS Casa Sollievo Della Sofferenza, in collaboration with the Institute for Soldier Nanotechnologies at MIT, have now demonstrated the repair of a chronically injured spinal cord by attempting to replace the fluid-filled cyst found in these lesions with a neuroprosthetics conducive to tissue reconstruction and axonal regeneration.
Spinal cord injury. (Image: Fabrizio Gelain; American Chemical Society)
"We managed, for the first time, to obtain a consistent regeneration of the nervous tissue in chronicized injuries at the spinal cord by using a nanostructured composite scaffold with no cells in it," Gelain tells Nanowerk. "Where usually in the damaged spinal cord there is scar tissue or a fluid filled cyst, nervous tissue regenerated and followed the direction given by our guidance channels. Hystological results were also supported by significant functional recovery of the treated animals."
Reporting their findings in a recent issue of ACS Nano ("Transplantation of Nanostructured Composite Scaffolds Results in the Regeneration of Chronically Injured Spinal Cords"), the team provided the proof-of-principle that nanotechnology has the tremendous potential of offering nanostructured scaffolds that now must be considered as a new strategy among the already known set of promising approaches for spinal cord injury (cell therapy, rehabilitation, etc).
"By themselves, nanostructured scaffolds probably will not solve the problem of regenerating chronic and acute spinal cord injury" says Gelain. "However, they will become a necessary component of an effective multi-disciplinary therapy in the near future. Moreover, we demonstrated that two different techniques like self-assembling and electrospinning can synergically work together to achieve the
specific goal of central nervous system regeneration."
Spinal cord injury in humans involves the permanent destruction of the nervous tissue. Within the affected regions, the mechanical substrates that provide physical support for axonal regeneration and three-dimensional positional information as well as the cytoarchitectural organization required for effective nerve regrowth have gone permanently lost. These holes in the spinal cord tissue represent an insurmountable barrier for axonal regeneration.
Gelain points out that the most pressing issue in chronic spinal cord injury is to warrant a suitable level of anatomical, histological, and cellular reconstruction at the lesion site. "Thus, the scar tissue and hollow cysts should be replaced with new neural tissue, permissive for both axonal regrowth and lesion bridging."
To that end, the Italian team engineered neural prosthetics made of composite nanostructured synthetic scaffolds, constituted of functionalized self-assembling peptides injected into electrospun nanostructured polymeric guidance channels, loaded with pro-regenerative drugs. They then implanted these guidance channels into cysts (cavities) of the damaged spinal cord of rats.

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