A comparative study of MTA solubility in various media

INTRODUCTION: Solubility of root filling materials is heavily influenced by the environment they are in contact with. This study compared the solubility of ProRoot MTA in deionized water and synthetic tissue fluid. MATERIALS & METHODS: Forty specimens of prepared MTA were immersed in deionized water and synthetic tissue fluid (20 samples each). The solubility was assessed after 7 and 28 days. Scanning electron microscope observation was also performed. The mean weight loss was evaluated using a digital scale. Data were analyzed using one-way ANOVA. Tukey test was performed for multiple comparisons. RESULTS: MTA solubility in synthetic tissue fluid was significantly lower than deionized water after 7 and 28 days (P<0.05). Secondary electron detectors revealed the presence of lumps and platelets on the surfaces of both specimens. Also, more voids were observed in specimen stored in deionized water. CONCLUSION: MTA dissolved faster in deionized water than synthetic tissue fluid. Despite this, the solubility of this material in both media was acceptable.

The role of metalloproteinase and hypoxia conditions in endometrial cells and embryo implantation

In the process of implantation, metalloproteinase enzymes play a key role in basement membrane degradation and endometrial extracellular matrix. The activity of these enzymes is impeded by binding Tissue Inhibitors of Metalloproteinase (TIMP). The oxygen concentration in the mammalian uterus at the time of implantation is about 2-5%. It is seen that the imposition of hypoxia on cancer cells increases the expression of metalloproteinase enzymes and reduces the expression of metalloproteinase inhibitors, resulting in increased cell invasion. To know the effect of Hypoxia-Inducible Factor (HIF) and other related factors, we decided to evaluate hypoxic conditions on endometrial epithelial cells of the uterus and roll of matrix metalloproteinases (MMPs) on angiogenesis and invasion of the embryo during implantation. In this study, human and mouse endometrial epithelial cells were incubated for 24-48 hours in hypoxic conditions. Subsequently, the expression level of TIMP-1 was measured in mouse and human epithelial cells by Real-Time PCR technique. The cell viability in hypoxic conditions was evaluated by MTT assay. Our results demonstrated that hypoxia reduced the quantitative gene expression of TIMP-1 in the human and mouse endometrial epithelial cells compared to the control group. It can be concluded that applying hypoxic conditions by reducing the TIMP-1 expression and consequently increasing MMP expression, may improve the embryo implantation rate

Enhancement of Fibroblasts Outgrowth onto Polycaprolactone Nanofibrous Grafted by Laminin Protein Using Carbon Dioxide Plasma Treatment

A common approach in tissue engineering is to mimic the architecture of the natural extracellular matrix (ECM). The ECM plays an important role in regulating cellular behaviors by influencing cells with biochemical signals and topographical cues. Nanofibrous constructs have been used extensively as potential tissue engineering platforms. It is generally hypothesized that a close imitation of the ECM will provide a more conducive environment for cellular functions ranging from adhesion, migration, proliferation to differentiation. In this study, the polycaprolactone (PCL) nanofibers designed were then modified by carbon dioxide plasma and laminin in order to enhance the cell adhesion, spreading and proliferation. The samples were evaluated by attenuated total reflectancefourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscope (SEM), contact angle and finally, cell culture. ATR-FTIR structural analysis showed the presence of functional groups on the nanofibrous surfaces. The SEM images showed the average diameter of nanofibers to be about 100 - 300 nm for samples. The 82° difference was obtained in the contact angle analysis, obtained for the laminin-modified nanofibrous mat against the unmodified nanofibrous mat. Cellular investigation showed better adhesion and cell growth and proliferation of laminin-modified nanofibrous samples than other samples. Therefore, the modification of electrospun scaffolds with bioactive protein is beneficial as this can create an environment that consists of biochemical cues to further promote cell adhesion and proliferation

Immunization against leukemia inhibitory factor and its receptor suppresses tumor formation of breast cancer initiating cells in BALB/c mouse

Abstract Immunotherapy is a promising approach for specific targeting of cancer cells. Leukemia inhibitory factor (LIF) regulates several features of cancers and cancer stem cells (CSCs) through binding to LIF receptor (LIFR). In this study, we investigated the consensus of LIF and LIFR immunization on the growth of mouse mammary tumors. For this purpose, mouse LIF and LIFR were designed as truncated proteins, expressed in E. coli and then injected to mice as individual and mixed antigens. The results showed the production of neutralizing antibodies and secretion of interferon-γ and interleukin-2 in response to immunization. In continue, the immunized mice were subjected for tumor formation challenge by inoculation of the breast CSCs derived from MC4-L2 cells. Development of the breast tumors was observed in all the control mice, while the tumors appeared in 75% of animals in the LIF group. LIFR injection, individually or in combination with LIF, strongly inhibited the tumor growth to only 25% of the mice. Moreover, a delay in tumor appearance was observed in the immunized mice compared to the controls. Immunostaining of the tumor sections confirmed the expression of LIF and LIFR. In conclusion, LIF and LIFR might be effective targets for immunotherapy of the tumors that express these proteins