Introduction: One of the serious complications of stroke is memory impairment, which is considered as one of the complications of reperfusion of tissue. The present study was designed to compare the effect of administration of Trolox, carnosic acid and Human Chorionic Gonadotropin (HCG) immediately after reperfusion of the stroke tissue on the memory and hippocampal histology. Method: Ischemia-Reperfusion Model (IRI) was created by bilateral occlusion of the common carotid artery for 15 minutes and the first dose was administered immediately after reperfusion. 10 days after ischemia, passive avoidance memory test and apoptotic protein levels were evaluated. Results: Cerebral Ischemia perfusion reduced the time of latency in entering the dark box in the ischemic group. Administration of Trolox and HCG increased this latency time, while treatment with carnosic acid had no effect. Also, IRI significantly reduced the number of healthy cells in the hippocampus. Administration of Trolox, carnosic acid and HCG increased the number of healthy cells and decreased the expression of Caspase-3 and Bax, but significantly increased the expression of Bcl-2 compared to the ischemic group. Conclusion: Findings indicate the beneficial effects of HCG and Trolox on the improvement of memory and the number of healthy cells in the hippocampal region. It is worth noting that the amount of apoptosis in the hippocampus was significantly reduced by Trolox, HCG and Carnosic acid.

Implantation of a suitable nerve guide conduit (NGC) seeded with sufficient Schwann cells (SCs) is required to improve peripheral nerve regeneration efficiently. Given the limitations of isolating and culturing SCs, using various sources of stem cells, including mesenchymal stem cells (MSCs) obtained from nasal olfactory mucosa, can be desirable. Olfactory ecto-MSCs (OE-MSCs) are a new population of neural crestderived stem cells that can proliferate and differentiate into SCs and can be considered a promising autologous alternative to produce SCs. Regardless, a biomimetic physicochemical microenvironment in NGC such as electroconductive substrate can affect the fate of transplanted stem cells, including differentiation toward SCs and nerve regeneration. Therefore, in this study, the effect of 3D printed polycaprolactone (PCL)/polypyrrole (PPy) conductive scaffolds on differentiation of human OE-MSCS into functional SC-like phenotypes was investigated. Biological evaluation of 3D printed scaffolds was examined by in vitro culturing the OE-MSCs on samples surfaces, and conductivity showed no effect on increased cell attachment, proliferation rate, viability, and distribution. In contrast, immunocytochemical staining and real-time polymerase chain reaction analysis indicated that 3D structures coated with PPy could provide a favorable microenvironment for OE-MSCs differentiation. In addition, it was found that differentiated OE-MSCs within PCL/PPy could secrete the highest amounts of nerve growth factor and brain-derived neurotrophic factor neurotrophic factors compared to pure PCL and 2D culture. After co-culturing with PC12 cells, a significant increase in neurite outgrowth on PCL/PPy conductive scaffold seeded with differentiated OE-MSCs. These findings indicated that 3D printed PCL/PPy conductive scaffold could support differentiation of OE-MSCs into SC-like phenotypes to promote neurite outgrowth, suggesting their potential for neural tissue engineering applications.

Strategies of Schwann cell (SC) transplantation for regeneration of peripheral nerve injury involve many limitations. Stem cells can be used as alternative cell source for differentiation into Schwann cells. Given the high potential of neural crest-derived stem cells for the generation of multiple cell lineages, in this research, we considered whether olfactory ectomesenchymal stem cells (OE-MSCs) derived from neural crest can spontaneously differentiate into SC lineage. OE-MSCs were isolated from human nasal mucosa and characterized by the mesenchymal and neural crest markers. The cells were cultured in glial growth factors-free medium and further investigated in terms of the phenotypic and functional properties. Immunocytochemical staining and real-time PCR analysis indicated that the cultured OE-MSCs expressed SCs markers, SOX10, p75, S100, GFAP and MBP, differentiation indicative. It was found that the cells could secrete neurotrophic factors, including brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF). Furthermore, after co-cultured with PC12, the mean neurite length was enhanced by OE-MSCs. The findings indicated that OE-MSCs could be differentiated spontaneously into SC-like phenotypes, suggesting their applications for transplantation in peripheral nerve injuries.Strategies of Schwann cell (SC) transplantation for regeneration of peripheral nerve injury involve many limitations. Stem cells can be used as alternative cell source for differentiation into Schwann cells. Given the high potential of neural crest-derived stem cells for the generation of multiple cell lineages, in this research, we considered whether olfactory ectomesenchymal stem cells (OE-MSCs) derived from neural crest can spontaneously differentiate into SC lineage. OE-MSCs were isolated from human nasal mucosa and characterized by the mesenchymal and neural crest markers. The cells were cultured in glial growth factors-free medium and further investigated in terms of the phenotypic and functional properties. Immunocytochemical staining and real-time PCR analysis indicated that the cultured OE-MSCs expressed SCs markers, SOX10, p75, S100, GFAP and MBP, differentiation indicative. It was found that the cells could secrete neurotrophic factors, including brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF). Furthermore, after co-cultured with PC12, the mean neurite length was enhanced by OE-MSCs. The findings indicated that OE-MSCs could be differentiated spontaneously into SC-like phenotypes, suggesting their applications for transplantation in peripheral nerve injuries.