Anti-apoptotic effect of Nisin as a prebiotic on human mesenchymal stem cells in harsh condition.

Mesenchymal stem cells (MSCs) are progenitor cells of connective tissue with the ability of proliferation, self-renewal, and multilineage differentiation that make it a promising source with an enormous potential to be utilized for tissue repairing and vehicles of cell-based gene therapy. The low survival rate of MSCs following transplantation is their drawback. Preconditioning with some factors is a novel and effective strategy, improving the survival of the cells by protecting them from harmful conditions and result in the good recovery of injured tissues. Nisin is a prebiotic with antimicrobial activity. This manuscript aimed to evaluate the effect of Nisin preconditioning of MSCs on in vitro cell viability. MSCs were cultured and preconditioned with Nisin in different concentrations. Then, they are separately exposed to H2O2 and serum deprivation. Cell survival and cell apoptosis were evaluated by MTT assay and Real-time PCR, respectively. Furthermore, Annexin-PI staining and caspase activity was performed to visualize apoptotic cells. MSC-Nisin viability and proliferation significantly increased when exposed to H2O2 and serum deprivation, compared to that of MSCs. About 250 and 500 IU/mL of Nisin donate a significant anti-apoptotic impact to MSCs. Our data suggest that preconditioning with Nisin has been improved cell viability and the anti-apoptotic capacity of MSCs. However, the mechanism related to the protective properties of preconditioning and using this strategy in stem cell therapy requires more research.

Bone Marrow Stromal Cells Associated with Poly L-Lactic-Co-Glycolic Acid (PLGA) Nanofiber Scaffold Improve Transected Sciatic Nerve Regeneration.

Background: Although peripheral nerves show capacity for regeneration after injury to a certain extent, the extent of regeneration is not remarkable. Previous studies have suggested that through the production of growth factors or extracellular matrix components, mesenchymal stem cells may enhance nerve regeneration. Objectives: In the present study, the therapeutic potency of the Bone Marrow Stromal Cells (BMSCs) associated with Poly L-lactic-co-glycolic acid (PLGA) nanofiber Scaffolds on rat sciatic nerve repair was evaluated. Material and Methods: Thirty adult male Wistar rats (220-250 g) were divided randomly into six groups, including control 1 (transected sciatic nerve), control 2 (transected sciatic nerve and stitched), Sham, PLGA, BMSCs, and PLGA+BMSCs. Functional recovery was evaluated at the end of 2nd, 4th, 6th, and 8th weeks after surgery using sciatic functional index (SFI) and hot water test. After killing all rats at the end of 8th week, their sciatic nerves were removed, fixed, and processed for the histological examination and analysis by the Motic software. Results: A significant recovery of the sciatic nerve function was observed in the PLGA+BMSCs transplanted group at the 8th week after surgery as demonstrated by SFI and hot water findings. Histological examinations also showed a significant improvement in the PLGA+BMSCs group compared to the control 1, 2, Sham, PLGA and BMSCs groups. Conclusion: BMSCs associated with PLGA nanofiber scaffold might be useful for improving the functional peripheral nerve repair having some clinical outcome.

Presentation of a novel model of chitosan- polyethylene oxide-nanohydroxyapatite nanofibers together with bone marrow stromal cells to repair and improve minor bone defects.

OBJECTIVES: Various methods for repairing bone defects are presented. Cell therapy is one of these methods. Bone marrow stromal cells (BMSCs) seem to be suitable for this purpose. On the other hand, lots of biomaterials are used to improve and repair the defect in the body, so in this study we tried to produce a similar structure to the bone by the chitosan and hydroxyapatite. MATERIALS AND METHODS: In this study, the solution of chitosan-nanohydroxyapatite-polyethylene oxide (PEO) Nanofibers was produced by electrospinning method, and then the BMSCs were cultured on this solution. A piece of chitosan-nanohydroxyapatite Nanofibers with BMSCs was placed in a hole with the diameter of 1 mm at the distal epiphysis of the rat femur. Then the biomechanical and radiographic studies were performed. RESULTS: Biomechanical testing results showed that bone strength was significantly higher in the Nanofiber/BMSCs group in comparison with control group. Also the bone strength in nanofiber/BMSCs group was significant, but in nanofiber group was nearly significant. Radiographic studies also showed that the average amount of callus formation (radio opacity) in nanofiber and control group was not significantly different. The callus formation in nanofiber/BMSCs group was increased compared to the control group, and it was not significant in the nanofiber group. CONCLUSION: Since chitosan-nanohydroxyapatite nanofibers with BMSCs increases the rate of bone repair, the obtained cell-nanoscaffold shell can be used in tissue engineering and cell therapy, especially for bone defects.