Chitosan-coated Selenium nanoparticles enhance the efficiency of stem cells in the neuroprotection of streptozotocin-induced neurotoxicity in male rats.

Alzheimer's disease (AD) is one of the common neurodegenerative diseases characterized by memory impairment. The protective effects of stem cell-based therapy have been reported in AD. In this study, it was assumed that Chitosan-coated Selenium nanoparticles (ChSeNPs) increase the efficiency of stem cells in the attenuation of neurotoxicity in the rat AD model. The AD model was induced using Streptozotocin (STZ) and treated by the adipose-derived mesenchymal stem cells (AMSCs) and SeNPs/ChSeNPs (0.4 mg/kg). Passive avoidance learning and recognition memory were assessed using shuttle box and novel object recognition tasks. The amyloid-beta deposition, the injected cells' homing and survival, antioxidant capacity, and BDNF concentration were evaluated using the histological, biochemical, and ELISA methods. The results showed that the combined administration of ChSeNPs and AMSCs is more effective in increasing the step-through latency and discrimination index than administering SeNPs and stem cells. Combined therapy caused a significant increase in antioxidant capacity that ChSeNPs was more effective than SeNPs, while AMSCs beside SeNPs had a greater effect on BDNF levels compared to conventional treatment of nanoparticles or AMSCs alone. Ultimately, the homing and survival of the transplanted AMSCs were greater in the group that received both stem cells and ChSeNPs. Taken together, it seems that the administration of ChSeNPs enhances the efficiency of transplanted stem cells in decreasing the neurotoxicity induced by STZ through an increase in the antioxidant capacity.

Administration of Selenium Nanoparticles Reverses Streptozotocin-Induced Neurotoxicity in the male rats.

Alzheimer's disease is the most common neurodegenerative disease associated with deposition of amyloid-beta and the increased oxidative stress. High free radical scavenging ability of selenium nanoparticles (SeNPs) has been acknowledged, so in the present study, the effects of treatment with SeNPs on Streptozotocin (STZ)-induced neurotoxicity were evaluated in the male rats. Learning and memory impairment was induced by intraventricular injection of STZ. Following induction of memory impairment, the rats received 0.4 mg/kg of SeNPs daily for one month. Memory function, antioxidant capacity, and deposition of Amyloid ß (Aß) were assessed using the shuttle box task, biochemical methods, and Congo red staining. Injection of STZ caused memory impairment, a decrease in the level of total thiol group (TTG), and an increase in the malondialdehyde (MDA) content and deposition of Aß. Administration of SeNPs reversed the neurotoxicity induced by STZ. It seems that SeNPs likely had neuroprotective effects on the animal model of Alzheimer's disease through increasing antioxidants҆ capacity.

Amelioration of diabetes-induced testicular and sperm damage in rats by cerium oxide nanoparticle treatment.

Cerium oxide nanoparticles (CNPs) as an antioxidant have been used frequently to attenuate hyperglycaemia oxidative damage in different organs. We investigated the impact CNPs on the qualitative and quantitative sperm parameters, spermatogenesis and NFE2-related factor 2 (Nrf2) expression as a major contributor of antioxidant defence in the male diabetic rats. Twenty-four male rats were divided into four groups. Controls received only mouse food and water. Second group were treated with CNPs (30 mg kg-1  day-1 ) for 2 weeks. Rats in third group received streptozotocin (STZ) (60 mg/kg). In fourth group, animals became diabetic and received CNPs (30 mg kg-1  day-1 ) for 2 weeks. The results showed a significant abnormality in the sperm parameters and histopathological patterns of testes in the diabetic group compared to the control group and CNPs treatment significantly improved all testicular parameters. Following CNPs administration, sperm DNA fragmentation significantly reduced in the STZ-treated rats. Moreover, after CNPs intake in the STZ-treated rats, Nfr2 expression levels increased significantly. Overall, CNPs administration on the diabetic rates can attenuate detrimental effects of diabetes on the sperm potential fertility, sperm parameters, DNA integrity and Nrf2 expression levels. This study gives a future prospect to determine the role of CNPs in the context of diabetes.

Effect of Calcium-enriched Mixture (CEM) cement on increasing mineralization in stem cells from the dental pulps of human exfoliated deciduous teeth.

Background. Stem cells isolated from human exfoliated deciduous teeth (SHED) are highly capable of proliferation and differentiation into odontogenic, osteogenic, adipose tissue and neural cells. The aim of this study was to investigate the effect of CEM cement on increasing mineralization in stem cells of exfoliated deciduous teeth. Methods. Dental pulps were isolated from extracted exfoliating primary teeth and immersed in a digestive solution. The dental pulp cells were immersed in α-MEM (modified culture medium) and 10% fetal bovine serum (FBS) was added. The culture cells were used for mineral deposit formation after the third passage. The cells were cultured in osteogenic cell culture medium in the control group and in osteogenic culture medium supplemented with CEM cement in the case group. Alizarin red staining was used to evaluate the mineral deposit formation on day 21. Statistical significance was determined with t-test. Results. Quantification of alizarin red staining showed that cells exposed to CEM cement induced more mineralized nodules (P=0.03). Conclusion. Mineral deposit formation in SHEDs was stimulated by CEM cement. Based on these data it might be suggested that CEM could improve osteoblastic differentiation.

The Effect of 1α,25(OH)2D3 on Osteogenic Differentiation of Stem Cells from Dental Pulp of Exfoliated Deciduous Teeth.

STATEMENT OF THE PROBLEM: Stem cells from human exfoliated deciduous teeth (SHEDs) are a population of highly proliferative cells, being capable of differentiating into osteogenic, odontogenic, adipocytes, and neural cells. Vitamin D3 metabolites such as 1α, 25-dihydroxyvitamin D3 are key factors in the regulation of bone metabolism. PURPOSE: The aim of this study was to investigate the effect of 1α, 25-dihydroxyvitamin D3 on osteogenic differentiation (alkaline phosphatase activity and alizarin red staining) of stem cells of exfoliated deciduous teeth. MATERIALS AND METHOD: Dental pulp was removed from freshly extracted primary teeth and immersed in a digestive solution. Then, the dental pulp cells were immersed in α-MEM (minimum essential medium) to which 10% fetal bovine serum was added. After the third passage, the cells were isolated from the culture plate and were used for osteogenic differentiation. As a control group, the cells were cultured in osteogenic cell culture medium. As the case group, the cells were cultured in osteogenic culture medium supplemented with 100 nM 1α,25 (OH)2D3. The alkaline phosphatase (ALP) activity and alizarin red staining were analyzed to evaluate the osteogenic differentiation at day 21. The results were analyzed by using t-test. RESULTS: Compared with the control group, significant increase was observed in ALP activity of SHEDs after being treated with 1α,25(OH)2D3 (p= 0.002). Alizarin red staining demonstrated that the cells exposed to 1α,25(OH)2D3 induced higher mineralized nodules (p< 0.001). CONCLUSION: Osteoblast differentiation in SHEDs was stimulated by 1α,25(OH) 2D3. It can be concluded that 1α,25(OH)2D3 can improve osteoblastic differentiation.