Evaluation of Leukocyte Response due to Implant of a Controlled Released Drug Delivery System of Chitosan Hydrogel Loaded with Selenium Nanoparticle in Rats with Experimental Spinal Cord Injury

Introduction: Traumatic spinal cord injury (SCI) is one of the main injuries of the central nervous system. The aim of this study was to evaluate leukocyte changes following implantation of a controlled drug delivery system of chitosan hydrogel loaded with selenium nanoparticles in rats with spinal cord injury. Material and Methods: For this purpose, 60 adult female rats with experimental thoracic spinal cord compression were divided into three equal groups: control group (did not receive any medication), chitosan group (received chitosan hydrogels), and nanoselnium group (received chitosan hydrogels containing selenium nanoparticles). Total and differential white blood cell count and neutrophil to lymphocyte ratio were measured on days 3, 7, 21 and 28 after induction of spinal cord injury. Results: The results showed that the total white blood cells and lymphocytes in the control group was significantly higher than the chitosan and nanoselnium groups in the various times. In addition, it was found that although in the chitosan group, a decrease in neutrophil population was observed, but in the nanoselnium group, the decrease in neutrophil population was significantly more than the other groups. Significant reduction of neutrophils to lymphocytes ratio on the third day of the study was also observed in the nanoselenium group compared to the other two groups. Conclusion: Implantation of chitosan hydrogel loaded with selenium nanoparticles controls the leukocyte response after spinal cord injury and thus potentially has a neuroprotective effect on spinal cord injury by controlling the secretion of inflammatory cytokines from the leukocytes.