Dual-crosslinked in-situ forming alginate/silk fibroin hydrogel with potential for bone tissue engineering.

This study aimed to improve the mechanical and biological properties of alginate-based hydrogels. For this purpose, in-situ forming hydrogels were prepared by dual crosslinking of Alginate (Alg)/Oxidized Alginate (OAlg)/Silk Fibroin (SF) through simultaneous ionic gelation using CaCO3-GDL and Schiff-base reaction. The resulting hydrogels were characterized by FTIR, SEM, compressive modulus, and rheological tests. Compared to the physically-crosslinked alginate hydrogel, the compressive modulus of dual-crosslinked Alg/OAlg/SF hydrogel increased from 28 to 67 kPa, due to the covalent imine bond formation. Then, MTT and DAPI staining assays were performed to demonstrate the biocompatibility of hydrogel. Furthermore, the differentiation potential of bone marrow mesenchymal stem cells encapsulated in hydrogel scaffolds to bone tissue was tested by ALP activity, Alizarin Red staining, and real-time PCR. The overall results showed the potential of Alginate/Oxidized Alginate/Silk Fibroin hydrogel scaffold for bone tissue engineering applications.

Apoptosis Induced by Prednisolone Occurs without Altering the Promoter Methylation of BAX and BCL-2 Genes in Acute Lymphoblastic Leukemia Cells CCRF-CEM.

OBJECTIVE: one of the main mechanisms in which cancer cells are resistant to chemotherapy drugs and therapeutic strategies is resistance to apoptosis due to these anticancer factors. Regulating the expression of genes through epigenetics, especially regulation through methylation, is one of the key aspects of regulating gene expression and the function of genes, which is also regulated by the pathways regulating the pathway of apoptosis. The epigenetic regulatory phenomenon in cancer cells can undergo a change in regulation and induces resistance to apoptosis against chemotherapy and anticancer factors. The purpose of the present scrutiny was defined to probe the effect of subtoxic prednisolone dose on the level of promoter methylation and gene expression of BAX and BCL2 in the CCRF-CEM cells. METHODS: The treated cells by prednisolone, cultured in RPMI 1640 medium in standard condition. Alteration in promoter DNA methylation was analyzed by use of methylation specific-PCR (MSP) technique after the defined intervened time of Prednisolone treatment with a subtoxic dose. RESULTS: Prednisolone can induce apoptosis via alteration in BAX and BCL2 genes, based on our previous scrutiny. This essay shows no varies in the Pattern of DNA methylation of examined genes; however, prednisolone changes the expression of examined genes. CONCLUSION: Lack of alteration through prednisolone treatment in DNA methylation template of BAX and BCL2 genes make this possible that Prednisolone affects apoptotic gene expression via different pathways, which need more research to be done about it.
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Evaluation of BAX and BCL-2 Gene Expression and Apoptosis Induction in Acute Lymphoblastic Leukemia Cell Line CCRFCEM after High- Dose Prednisolone Treatment

Objective: Glucocorticoids are one of the most important drugs in the treatment of acute lymphoblastic leukemia for children. It is very important to response to glucocorticoid in the prognosis of these patients. Therefore, resistance to treatment is a major problem in lymphoid leukemia cases. In, this study, CCRF-CEM cell line was selected as a chemotherapy-resistant model. The aim of this study was to evaluate the effect of high dose prednisolone on induction of apoptosis and changes in BAX and BCL-2 gene expression at different times. Methods: CCRF-CEM cell lines were grown in standard conditions. Based on previous studies, a dose of 700 µM as subtoxic dose was selected. Changes in gene expression of BAX and BCL-2 were evaluated by using real time PCR techniques. Also stained with annexin V and the induction of apoptosis was assessed by FACS machine. Results: In this study it was found that prednisolone in high doses at different times significantly increased the gene expression of BAX and on the other hand the amount of BCL-2 expression was reduced. Cells that treated for 48 hours had more significant changes in gene expression. Based on flowcytometry data, prednisolone can induce apoptosis in a time dependent manner on this cancerous resistant cell line. Conclusions: Apoptosis induced by high-dose prednisolone in the CCRF-CEM cells, which is almost resistant, and possibly mediated by reducing the expression of BCL-2 and BAX up-regulation.

Using quantum chemical modeling and calculations for evaluation of cellulose potential for estrogen micropollutants removal from water effluents.

This paper is devoted to investigate the suitability of cellulose for estrogens micropollutants removal from water effluent. For this purpose, the sorption of eight estrogens including Estradiol, Estrone, Testosterone, Progesterone, Estriol, Mestranol, Ethinylestradiol and Diethylstilbestrol were investigated. The charge density profiles and sorption curves were obtained and discussed using quantum chemical calculations where the Accelrys Materials Studio software and COSMO-SAC model were employed. The geometry optimization of compound molecule and energy minimizations was performed using the Dmol3 Module and density functional theory of generalized gradient approximate and Volsko-Wilk-Nusair functional. We found that cellulose cannot be a reliable choice of sorbent for removal of Estrone and Estradiol, but it is a poor choice of sorbent for removal of Estriol, Ethinylestradiol. Cellulose can be used for Diethylstilbestrol, Mestranol, Testosterone and Progesterone removal from estrogens containing effluents.