Preparation and Administration of a Controlled-Release Delivery System of Chitosan Hydrogel loaded with Methadone and Piroxicam in Experimental Defect of Tibial in Rats; Histopathological Evaluation

Purpose: In this study, a controlled release drug delivery system loaded with piroxicam and methadone was synthesized and used subcutaneously in rat with experimental tibial defect and healing were assessed histopathologically. Materials and Methods: For this purpose 100 adult female rats were were randomly divided into five equal groups; group control, chitosan group, piroxicam group, methadone group, and piroxicam-methadone group. The morphological structure of the synthesized drug systems was studied by scanning electron microscope. In addition, the structure of the hydrogels was investigated by fourier transform infrared spectroscopy and while releasing the hydrogels gelation time, the release of piroxicam and methadone from the hydrogels were evaluated in vitro.   Results: Histological results of the 3rd day of the study showed the lowest extent and severity of inflammation in the chitosan, piroxicam, and piroxicam-methadone groups, while on the 7th day, tissue inflammation and the extent of bleeding was lower in the piroxicam, methadone, and piroxicam-methadone groups than in the other groups. Evaluation of new bone formation on day 21 showed that the chitosan, piroxicam, and methadone groups had better repair than the other groups. Conclusion: It seems that in the control group that did not receive any treatment intervention, following the experimental bone defect, the highest inflammatory response was observed in histological examination and finally the weakest bone repair. On the other hand, the presence of piroxicam, methadone and chitosan in the piroxicam-methadone group (all of which have anti-inflammatory effects) also seems to have a negative effect on repair

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.&#x0D; 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.&#x0D; 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.&#x0D; 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.</jats:p