To better direct repair following spinal cord injury (SCI), we designed an implant modeled after the intact spinal cord consisting of a multicomponent polymer scaffold seeded with neural stem cells. Implantation of the scaffold–neural stem cells unit into an adult rat hemisection model of SCI promoted long-term improvement in function (persistent for 1 year in some animals) relative to a lesion-control group. At 70 days postinjury, animals implanted with scaffold-plus-cells exhibited coordinated, weight-bearing hindlimb stepping. Histology and immunocytochemical analysis suggested that this recovery might be attributable partly to a reduction in tissue loss from secondary injury processes as well as in diminished glial scarring. Tract tracing demonstrated corticospinal tract fibers passing through the injury epicenter to the caudal cord, a phenomenon not present in untreated groups. Together with evidence of enhanced local GAP-43 expression not seen in controls, these findings suggest a possible regeneration component. These results may suggest a new approach to SCI and, more broadly, may serve as a prototype for multidisciplinary strategies against complex neurological problems

A dual scaffold structure made of biodegradable polymers and seeded with neural stem cells has been developed to address the issues of spinal cord injury including axonal severance and the loss of neurons and glia. The general design of the scaffold is derived the structure of the spinal cord with an outer section which mimics the white matter with long axial pores to provide axonal guidance and an inner section seeded with neural stem cells to address the issues of cell replacement and mimic the general character of the gray matter. The seeded scaffold leads to improved functional recovery as compared with the lesion control or cells alone following spinal cord injury.