Characterization of mesenchymal stem cells from human dental pulp, preapical follicle and periodontal ligament

Human dental stem cells have high proliferative potential for self-renewal that is important to the regenerative capacity of the tissue. The aim was to isolate human dental pulp stem cells [DPSC], periodontal ligament stem cells [PDLSC] and periapical follicle stem cells [PAFSC] for their potential role in tissue regeneration. In this experimental study, the postnatal stem cells were isolated from dental pulp, preapical follicle and periodontal ligament .The cells were stained for different stem cell markers by immunocytochemistry. To investigate the mesenchymal nature of cells, differentiation potential along osteoblastic and adipogenic lineages and gene expression profile were performed. For proliferation potential assay, Brdu staining and growth curve tests were performed. Finally, all three cell types were compared together regarding their proliferation, differentiation and displaying phenotype. The isolated cell populations have similar fibroblastic like morphology and expressed all examined cell surface molecule markers. These cells were capable of differentiating into osteocyte with different capability and adipocyte with the same rate. PAFSCs showed more significant proliferation rate than others. Reverse transcriptase PCR [RT-PCR] for nanog, oct4, Alkaline phosphatase [ALP] and glyceraldehydes-3-phosphate dehydrogenease [GADPH] as control gene showed strong positive expression of these genes in all three isolated cell types. PDLSCs, DPSCs and PAFSCs exist in various tissues of the teeth and can use as a source of mesenchymal stem cells for developing bioengineered organs and also in craniomaxillofacial reconstruction with varying efficiency in differentiation and proliferation

Evaluating the role of silver nanoparticles on acrosomal reaction and spermatogenic cells in rat

Nanoparticles have wide range of application while there are some reports regarding their probable effects on male reproductive system and spermatozoa. The aim of this study was to evaluate the effect of different doses of silver nanoparticles [AgNPs] [70nm] on acrosome of rat spermatozoa and number of spermatogenic cells. In this experimental study, in experimental group, 32 male wistar rats [8 rats/group] received oral feeding AgNPs every 12 hr in one spermatogenesis period [48 days] by means of gavages in 25, 50, 100 and 200 mg/kg concentration [experimental groups 1-4, respectively]. The control group [8 rats] was treated on schedule with distilled water. Spermatozoa were stained by triple staining protocol for acrosome reaction. Histological evaluation on testis sections was performed using tissue processing and hematoxylin-eosin [H and E] staining. There was significant difference between the control group and the experimental group 1 for acrosome reaction [11.00 +/- 0.00 and 24.25 +/- 3.68, respectively, p=0.01]. There was only significant reduction in spermatogonia cells in experimental group 4. Experimental groups 2, 3 and 4 showed a significant reduction in the number of primary spermatocytes and spermatids as well as spermatozoa. But there were no significant differences between different groups for Sertoli cell number and seminiferous tubule diameter. It seems that Ag NPs have acute and significant effects on spermatogenesis and number of spermatogenic cells and also on acrosome reaction in sperm cells. More experimental investigations are necessary to elucidate better conclusion regarding the safety of nanoparticles on male reproduction system.