Abstract

Introduction: Cell therapy is known as one of the most common methods used for treating a spinal cord injury (SCI); particularly, olfactory ensheathing cells (OECs), which have attracted much more attention among scholars due to their properties such as promotion of axonal regeneration, remyelination, and angiogenesis. Thus, the present study compared the effects of transplanted OECs on functional improvement and axonal regeneration of contused rats during acute and delayed phases. Material and Methods: For this purpose, a total of 56 male Wistar rats were randomly divided into eight groups including sham, control, three vehicle groups (immediately, 3 and 7 days after injury), and three cell transplantation groups (immediately, 3 and 7 days following injury). The sham group had experienced only laminectomy and other groups had undergone the SCI. The olfactory mucosa of the 7-day-old rat pups was also used for cell culture. The cell type was then confirmed by immunocytochemistry. In the vehicle and cell transplantation groups, the cell culture medium was injected by itself or accompanied by cells, respectively. Subsequently, the motor function was evaluated. Finally, luxol fast blue (LFB) staining was used for histological assessment. Results: Motor test results showed an increase in the Basso, Beattie, and Bresnahan locomotor scale scores immediately after injury in the transplantation group compared to those in other two cell-treated groups; but it was not significant. Discussion and Conclusion: Based on the LFB staining results, the regeneration rate in the transplantation group immediately after injury was considerably higher than that in two other treated groups. Therefore, considering these findings, it seemed that cell transplantation immediately after injury was better than that 3 and 7 days following injury.