Introduction: We designed a thermo-sensitive, biodegradable chitosan-gelatin hydrogel for neuroprotection and growth factor delivery after neurotrauma. The functional outcomes were evaluated after application of this hydrogel in rat model of severe spinal cord injury

Methods: Adult SD rats were randomly assigned to a control (spinal cord injury only) and two experimental groups (topical hydrogel, and topical hydrogel with GDNF). We induced severe contusion spinal cord injury by a computer-controlled impactor. In the topical group, hydrogel solution was placed on the cord surface at the lesion epicenter. All animals were followed for 12 weeks and weekly behavioral testing was performed using the BBB scale (minimum 0, maximum 21). Immunohistochemistry was performed to study scar formation, and tissue preservation.

Results: The application of hydrogel did not adversely affect the functional outcomes. The BBB scores were significantly better in the topical group as compared to the control group. Inclusion of GDNF further improved functional outcomes. Immunohistochemistry revealed preservation of neuronal bridge across the injury epicenter.

Conclusions: The application of chitosan-gelatin hydrogel improves functional outcomes when combined with GDNF in a rat model of severe spinal cord injury. Further studies are warranted to optimize its effects and evaluate in large animal models.

Patient Care: The chitosan-gelatin hydrogel has a potential for clinical application for neuroprotection after spinal cord injury.

Learning Objectives: Topical application of chitosan-gelatin hydrogel improves functional outcomes after severe contusion spinal cord injury in rats.

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