Combined effect of Cerium oxide nanoparticles loaded scaffold and photobiomodulation therapy on pain and neuronal regeneration following spinal cord injury: an experimental study.

BACKGROUND: Spinal cord injury (SCI) remained one of the challenges to treat due to its complicated mechanisms. Photobiomodulation therapy (PBMT) accelerates neuronal regeneration. Cerium oxide nanoparticles (CeONPs) also eliminate free radicals in the environment. The present study aims to introduce a combined treatment method of making PCL scaffolds as microenvironments, seeded with CeONPs and the PBMT technique for SCI treatment. METHODS: The surgical hemi-section was used to induce SCI. Immediately after the SCI induction, the scaffold (Sc) was loaded with CeONPs implanted. PBMT began 30 min after SCI induction and lasted for up to 4 weeks. Fifty-six male rats were randomly divided into seven groups. Glial fibrillary acidic protein (GFAP) (an astrocyte marker), Connexin 43 (Con43) (a member of the gap junction), and gap junctions (GJ) (a marker for the transfer of ions and small molecules) expressions were evaluated. The behavioral evaluation was performed by BBB, Acetone, Von Frey, and radiant heat tests. RESULT: The SC + Nano + PBMT group exhibited the most remarkable recovery outcomes. Thermal hyperalgesia responses were mitigated, with the combined approach displaying the most effective relief. Mechanical allodynia and cold allodynia responses were also attenuated by treatments, demonstrating potential pain management benefits. CONCLUSION: These findings highlight the potential of PBMT, combined with CeONPs-loaded scaffolds, in promoting functional motor recovery and alleviating pain-related responses following SCI. The study underscores the intricate interplay between various interventions and their cumulative effects, informing future research directions for enhancing neural repair and pain management strategies in SCI contexts.

The effect of gabapentin and pregabalin administration on memory in clinical and preclinical studies: a meta-analysis and systematic review.

BACKGROUND: Today, gabapentinoids such as Gabapentin (GBP) and pregabalin (PGB) are widely used as painkillers. This may alter the function of the nervous system; hence their results may include a difference in memory and processes that end in memory formation. This study aims to conclude whether gabapentinoids can alter memory or not by reviewing and analyzing clinical and preclinical studies. MATERIAL AND METHODS: A comprehensive search was carried out in databases including PUBMED, EMBASE, SCOPUS, and Web of Science. In the included studies, memory was measured as an outcome variable in clinical or preclinical studies. RESULT: A total of 21 articles (4 clinical, 17 preclinical) were included in the meta-analysis by STATA Software. The results showed that memory changes under the influence of GBP. Both the administrated dosage and the time of administration are important in the final results and latency time of retention. GBP administration in healthy animals increased latency time, whereas if the administration of GBP took place exactly before training, the latency time increased slightly. Short-term administration of PGB in healthy volunteers is accompanied by transient side effects on the CNS. However, the number and homogeneity of the studies were not such that a meta-analysis could be performed on them. CONCLUSION: Clinical and preclinical studies showed that PGB administration did not confirm its improving memory effect. GBP administration in healthy animals increased latency time and improved memory. Although it depended on the time of administration.

Study of nerve cell regeneration on nanofibers containing cerium oxide nanoparticles in a spinal cord injury model in rats.

Since the CNS is unable to repair itself via neuronal regeneration in adult mammals, alternative therapies need to be found. The use of cerium oxide nanoparticles to repair nerve damage could be a promising approach for spinal cord reconstruction. In this study, we constructed a scaffold containing cerium oxide nanoparticles (Scaffold-CeO2) and investigated the rate of nerve cell regeneration in a rat model of spinal cord injury. The scaffold of gelatin and polycaprolactone was synthesized, and a gelatin solution containing cerium oxide nanoparticles was attached to the scaffold. For the animal study, 40 male Wistar rats were randomly divided into 4 groups (n = 10): (a) Control; (b) Spinal cord injury (SCI); (c) Scaffold (SCI + scaffold without CeO2 nanoparticles); (d) Scaffold-CeO2 (SCI + scaffold containing CeO2 nanoparticles). After creation of a hemisection SCI, scaffolds were placed at the site of injury in groups c and d, and after 7 weeks the rats were subjected to behavioral tests and then sacrificed for preparation of the spinal cord tissue to measure the expression of G-CSF, Tau and Mag proteins by Western blotting and Iba-1 protein by immunohistochemistry. The result of behavioral tests confirmed motor improvement and pain reduction in the Scaffold-CeO2 group compared to the SCI group. Decreased expression of Iba-1 and higher expression of Tau and Mag in the Scaffold-CeO2 group compared to the SCI group could be the result of nerve regeneration caused by the scaffold containing CeONPs as well as relief of pain symptoms.