Modares Journal of Biotechnology

Abstract Stem cells are characterized by their capacity for self-renewal and their ability to differentiate into specific cell types under the influence of their microenvironment. It is known that matrix chemistry controls stem cell differentiation. Single cell encapsulations of the Mesenchymal stem cells into a semi-permeable microgel, allows a greater control of the stem cell fate. In this study, a chip for single-cell encapsulation was designed and fabricated using microfluidic technology. By using microfluidic chip, human bone marrow mesenchymal stem cells (hBMSCs) are encapsulated inside alginate and alginate-poly-l lysine (PLL) microgels. The results of long-term viability of MSCs inside alginate-PLL microgels, shows a significant increase compared to alginate microgels. Mesenchymal stem cell proliferation in alginate-PLL microgels also increased significantly on days 14 and 21. It seems that PLL improves cell adhesion and function by creating a positively charged matrix. Microscopic studies indicate that the morphology of the cells inside the microgels is spherical. However, the average diameter and volume of cells in microgels containing PLL are smaller than others, which indicates more proliferation and space limitation inside the microgels. Therefore, single cell alginate-PLL microgels provide a suitable substrate in clinical studies for tissue engineering, organ transplantation and cell therapy.

Abstract Aims: Nitric oxide (NO) plays an important role in maintaining cellular stem status, and the range of electromagnetic fields (EMF) is very deep in contrast to the electric field. The aim of this study was to investigate the effect of electromagnetic field and nitric oxide on the neural differentiation proteins marker and viability of the rat bone marrow mesenchymal stem cells.
Materials and Methods: The present experimental research was conducted on bone marrow mesenchymal stem cells of Vistar rats. For treatments of the cells, high (1mM) and low (10micromolar Deta-NO) concentrations were used as a nitric oxide donor molecule and 50Hz low-frequency electromagnetic field and they were compare with the control group. The cell viability was recorded by MTT assay test, the neural differentiation pathway gene expression was investigated by RT-PCR technique, and the neural differentiation marker protein expression was evaluated by Immunocytochemistry technique. The data were analyzed by one-way ANOVA, using SPSS 13 software.
Findings: After 24 hours of treatment with nitric oxide and EMF, the rate of viability in all groups was significantly decreased compared to the control group. After 48 hours, EMF alone, as well as with low concentration of nitric oxide did not decrease the rate of viability and cell growth increased compared to the control group. In the group treated with high nitric oxide concentration along with EMF, MAP2 protein was expressed in the number of cells more than the control group and the one treated with EMF.
Conclusion: The electromagnetic field, along with its high concentration of nitric oxide, decreases the number of rat bone marrow mesenchymal stem cells and, by increasing cell size, gene expression and neural differentiation proteins marker facilitates their differentiation to nerve-like cells.