Combinational treatment approach for traumatic spinal cord injury

Abstract

Spinal cord injury (SCI) is devastating and debilitating, and currently no effective treatments exist. Approximately, 12,000 new cases of SCI occur annually in the United States alone. The central nervous system has very low repair capability after injury, due to the toxic environment in the injured tissue. After spinal cord trauma, ruptured blood vessels cause neighboring cells and tissues to be deprived of oxygen and nutrients, and result in the accumulation of carbon dioxide and waste. New blood vessels form spontaneously after SCI, but then retract as the injured tissue forms a cavity. Thus, the newly formed vasculature likely retracts because it lacks a structural support matrix to extend across the lesion. Currently, in the field of spinal cord injury, combinational treatment approaches appear to hold the greatest therapeutic potential. Therefore, the aim of these studies was to transplant a novel, non-immunogenic, bioengineered hydrogel, into the injured spinal cord to serve as both a structural scaffold (for blood vessels, axons, and astrocytic processes), as well as a functional matrix with a time-controlled release of growth factors (Vascular endothelial growth factor, VEGF; Glial cell line-derived neurotrophic factor, GDNF). The benefit of this hydrogel is that it remains liquid at cooler temperatures, gels to conform to the space surrounding it at body temperature, and was designed to have a similar tensile strength as spinal cord tissue. This is advantageous due to the non-uniformity of lesion cavities following contusive spinal cord injury. Hydrogel alone and combinational treatment groups significantly improved several measures of functional recovery and showed modest histological improvements, yet did not provoke any increased sensitivity to a thermal stimulus. Collectively, these findings suggest that with further investigation, hydrogel along with a combination of growth factors might be a useful therapeutic approach for repairing the injured spinal cord.