Enhancement of targeted therapy in combination with metformin on human breast cancer cell lines.

BACKGROUND: Breast cancer remains a primary global health concern due to its limited treatment options, frequent disease recurrence, and high rates of morbidity and mortality. Thereby, there is a need for more effective treatment approaches. The proposal suggests that the combination of targeted therapy with other antitumoral agents could potentially address drug resistance. In this study, we examined the antitumoral effect of combining metformin, an antidiabetic drug, with targeted therapies, including tamoxifen for estrogen receptor-positive (MCF-7), trastuzumab for HER2-positive (SKBR-3), and antibody against ROR1 receptor for triple-negative breast cancer (MDA-MB-231). METHODS: Once the expression of relevant receptors on each cell line was confirmed and appropriate drug concentrations were selected through cytotoxicity assays, the antitumor effects of both monotherapy and combination therapy on colony formation, migration, invasion were assessed in in vitro as well as tumor area and metastatic potential in ex ovo Chick chorioallantoic membrane (CAM) models. RESULTS: The results exhibited the enhanced effects of tamoxifen when combined with targeted therapy. This combination effectively inhibited cell growth, colony formation, migration, and invasion in vitro. Additionally, it significantly reduced tumor size and metastatic potential in an ex ovo CAM model. CONCLUSIONS: The findings indicate that a favorable strategy to enhance the efficacy of breast cancer treatment would be to combine metformin with targeted therapies.

The effect of source animal age, decellularization protocol, and sterilization method on bovine acellular dermal matrix as a scaffold for wound healing and skin regeneration.

BACKGROUND: Healing the full-thickness skin wounds has remained a challenge. One of the most frequently used grafts for skin regeneration is xenogeneic acellular dermal matrices (ADMs), including bovine ADMs. This study investigated the effect of the source animal age, enzymatic versus non-enzymatic decellularization protocols, and gamma irradiation versus ethylene oxide (EO) sterilization on the scaffold. METHODS: ADMs were prepared using the dermises of fetal bovine or calf skins. All groups were decellularized through chemical and mechanical methods, unless T-FADM samples, in which an enzymatic step was added to the decellularization protocol. All groups were sterilized with ethylene oxide (EO), except G-FADM which was sterilized using gamma irradiation. The scaffolds were characterized through scanning electron microscopy, differential scanning calorimetry, tensile test, MTT assay, DNA quantification, and real-time PCR. The performance of the ADMs in wound treatment was also evaluated macroscopically and histologically. RESULTS: All ADMs were effectively decellularized. In comparison to FADM (EO-sterilized fetal ADM), morphological, and mechanical properties of G-FADM, T-FADM, and CADM (EOsterilized calf ADM) were changed to different extents. In addition, the CADM and G-FADM were thermally more stable than the FADM and T-FADM. Although all ADMs were noncytotoxic, the wounds of the FADM, T-FADM, and G-FADM groups were contracted to almost 30.0% of the original area on day 7, significantly faster than the CADM (17.5% ± 1.7) and control (12.2% ± 1.59) groups. However, by day 21, all ADMs were mostly closed except for the untreated group (60.1 ± 1.8). CONCLUSION: Altogether, fetal source and EO-sterilized samples performed better than calf source and gamma-sterilized samples unless in some mechanical properties. There was no added value in using enzymatic treatment during the decellularization process. Our results suggest that the age, decellularization, and sterilization methods of animal source should be selected based on the clinical requirements.

Generation of glucose sensitive insulin-secreting cells from human induced pluripotent stem cells on optimized polyethersulfone hybrid nanofibrous scaffold.

BACKGROUND: In the realm of diabetes treatment, various strategies have been tried, including islet transplantation and common drug therapies, but the limitations of these procedures and lack of responsive to the high number of patients have prompted researchers to develop a new method. In recent decades, the use of stem cells and three-dimonsional (3D) scaffold to produce insulin-secreting cells is one of the most promising new approaches. Meanwhile, human-induced pluripotent stem cells (iPSCs) propose due to advantages such as autologousness and high pluripotency in cell therapy. This study aimed to evaluate the differentiation of iPSCs into pancreatic islet insuli-producing cells (IPCs) on Silk/PES (polyethersulfone) nanofibers as a 3D scaffold and compare it with a two-dimonsional (2D) cultured group. METHODS: Investigating the functional, morphological, molecular, and cellular characteristics of differentiated iPSCs on control cultures (without differentiation medium), 2D and 3D were measured by various methods such as electron microscopy, Q-PCR, immunofluorescence, western blot, and ELISA. RESULTS: This investigation revealed that differentiated cells on the 3D Silk/PES scaffold expressed pancreatic specific-markers such as insulin and pdx1 at higher levels than the control and 2D groups, with a significant difference between the two groups. All results of Q-PCR, immunocytochemistry, and western blot showed that IPCs in the silk/PES 3D group was more efficient than in the 2D group. In the face of these cases, the release of insulin and C-peptide in response to several concentrations of glucose in the 3D group was significantly higher than in the 2D culture. CONCLUSION: Finally, our findings displayed that optimized Silk/PES 3D scaffolds can enhance the differentiation of IPCs from iPSCs compared to the 2D culture group.

Anti-inflammatory and tissue repair effect of cinnamaldehyde and nano cinnamaldehyde on gingival fibroblasts and macrophages.

BACKGROUND: Recurrent aphthous stomatitis has a complex and inflammatory origin. Among the great variety of medications it is increasingly common to use herbal medicines due to the adverse side effects of chemical medications. Considering the anti-inflammatory properties of cinnamaldehyde and the lack of studies related to the effectiveness of its nano form; This study investigates the effect of cinnamaldehyde and nano cinnamaldehyde on the healing rate of recurrent aphthous stomatitis lesions. METHODS: In a laboratory experiment, cinnamaldehyde was converted into niosomal nanoparticles. The niosome vesicles diameter and polydispersity index were measured at 25°C using a dynamic light scattering (DLS) Mastersizer 2000 (Malvern Panalytical technologies: UK) and Zetasizer Nano ZS system (Malvern Instruments Worcestershire: UK). After characterizing these particles, the (2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide) [XTT] assay was used to assess the toxicity of cinnamaldehyde and nano cinnamaldehyde on gingival fibroblast (HGF) and macrophage (THP-1) cells. By determining the release of TNF-α, IL-6, and TGF-ß cytokines using ELISA kits, the level of tissue repair and anti-inflammatory capabilities of these two substances were evaluated. RESULTS: The size and loading rate of the cinnamaldehyde nanoparticles were established after its creation. The optimized nanovesicle exhibited the following characteristics: particle size of 228.75 ± 2.38 nm, PDI of 0.244 ± 0.01, the zeta potential of -10.87 ± 1.09 mV and the drug encapsulation percentage of 66.72 ± 3.93%. PDIs range was between 0.242-0.274. The zeta potential values at 25°C were from -2.67 to -12.9 mV. The results of the XTT test demonstrated that nano cinnamaldehyde exhibited dose-dependent toxicity effects. Moreover, nano cinnamaldehyde released more TGF-ß and had better reparative effects when taken at lower concentrations than cinnamaldehyde. CONCLUSION: Nano cinnamaldehyde and cinnamaldehyde are effective in repairing tissue when used in non-toxic amounts. After confirmation in animal models, it is envisaged that these substances can be utilized to treat recurrent aphthous stomatitis.

Enhanced yield of cholinergic neurons from induced pluripotent stem cells (iPSC): A two-step induction protocol.

BACKGROUND: Cholinergic neurons, a type of neurons found in central nervous system, play a vital role in muscle movement and activities. Cholinergic neurons degeneration is the main pathological symptom of neurodegenerative diseases. Among a variety of stem cells, iPSCs have emerged as a promising candidate for transplantation to improve the repair of neuronal lesion sites. However, the establishment of an appropriate induction method to yield large numbers of cholinergic neurons has yet to be determined. Here, we studied the differentiation potential of iPSCs to generate cholinergic neurons by developing a new optimized differentiation protocol. METHODS: The iPSCs were harvested on 6-well matrigel-coated plate and incubated with serum­free DMEM/F12 with 2 % B27 supplement, 20 ng/ml the basic fibroblast growth factor and 20 ng/ml epidermal growth factor for 48 hours. Then, the pre-induced cells were treated in neuronal induction medium supplemented with all-trans retinoic acid, sonic hedgehog, 100 ng/ml glial-derived neurotrophic factor and 200 ng/ml brain-derived neurotrophic factor for 7 days. Cell viability during induction stages was tested by MTT assay. Differentiated cells were evaluated with crystal violet staining, immunocytochemistry and real­time PCR. RESULTS: Our results showed that the survival rate of iPSCs leveled out and was similar to that in the control group following the differentiation process. Immunochemistry results revealed that the expression of ChAT was observed in cells in both pre­induction and induction stages with a significantly higher expression level at the induction stage as compared to the pre-induction stage. However, none of these markers was expressed in the iPSCs. Cresyl violet staining confirmed the neuronal phenotype of differentiated cells. The induction group significantly expressed the higher levels of Islet1, Olig2 and HB9, whereas pluripotency markers including those of Oct4 and Nestin plunged. CONCLUSION: Our investigation represents a highly efficient protocol for iPSCs differentiation toward cholinergic neurons which could be used for further preclinical transplantation studies (Tab. 1, Fig. 5, Ref. 35). Text in PDF www.elis.sk Keywords: induced pluripotent stem cells, cholinergic neurons, neurotrophic factors, induction protocol, preclinical transplantation.

Application of iPSCs derived pancreatic ß-like cells using pancreatic bio-scaffold.

This study aimed toengineer a pancreatic tissue. Intact rat pancreases were successfully decellularized, and were reseeded with human-induced pluripotent stem cells using different 2D and 3D culture growth factors. The differentiation process was assessed for the presence of a pancreas-like tissue. The histology and SEM analysis revealed cell attachment in all samples, except for the Exp4, and the Flow-cytometry provided 87% viability for the differentiated cells. In Exp1, PDX1 with the positive expression of 2.87±0.06 was dramatically higher than Exp2 with a 2.44±0.06 reaction. NGN3-reactions were 8±0.1 and 6.6±0.2 in Exp1 and Exp2 at P < 0.05, respectively. C-peptide with the expression of 7.5±0.7 in Exp3 was almost equal to that in Exp1 and Exp2. Glucagon (5.1±1) and PDX1 (3.2±0.82) in Exp3 indicated no significant difference. The significant upregulations of pancreatic endocrine markers (PDX1 and NGN3), and the cell-specific glucose transporter (GLUT2) were observed in the differentiated IPCs in the 3D culture of Exp2 after 21 days. The highest insulin and C-peptide concentrations were observed in Exp2. In Exp3, insulin secretion in response to high glucose and 10 mM arginine was 42.43 ±6.34 µU/ml. A decellularized pancreas in the presence of hiPSCs and growth factors could be efficiently used as a natural scaffold.

Improved biological behaviours and osteoinductive capacity of the gelatin nanofibers while composites with GO/MgO.

Among the many polymers introduced for bone tissue engineering, natural polymers have more advantages due to their high biocompatibility and biodegradability, despite their low mechanical properties. Herein, gelatin nanofibers with and without magnesium oxide (MgO) and graphene oxide (GO) nanoparticles were fabricated by electrospinning. The fabricated gelatin and gelatin/GO/MgO nanofibers were examined using scanning electron microscopy, protein adsorption, cell attachment and viability assays. The results revealed that biological behaviours of the gelatin nanofibers significantly improved while incorporated with MgO and GO nanoparticles. In the following, osteosupportive capacity of the fabricated scaffolds was investigated by Alizarin-red staining, alkaline phosphatase activity, and calcium content, and bone-related gene and protein assays. The results revealed that the highest osteogenic differentiation potential of human-induced pluripotent stem cells (hiPSCs) was detected while these cells were cultured on the gelatin/GO/MgO nanofibers. However, these makers in the hiPSCs cultured on the gelatin nanofibers were also significantly increased in comparison with the cells cultured on the tissue culture plates as a control. In conclusion, the results revealed that predictable disadvantages in gelatin nanofibers can be greatly improved by the addition of MgO and GO nanoparticles, and the resulting composite scaffold could be a potential candidate for use in bone tissue engineering.

A novel hybrid polymer of PCL/fish gelatin nanofibrous scaffold improves proliferation and differentiation of Wharton's jelly-derived mesenchymal cells into islet-like cells.

BACKGROUND: Using a different source of stem cells to compensate for the lost beta cells is a promising way to cure diabetic patients. Besides, the best efficiency of insulin-producing cells (IPCs) will appear when we culture them in an environment similar to inside the body. Hence, three-dimensional (3D) culture ameliorates the differentiation of diverse kinds of stem cells into IPCs compared to those differentiated in two-dimensional (2D) culture. In this study, we aim to create an ideal differentiation environment by using PCL/Fish gelatin nanofibrous scaffolds to differentiate Wharton's jelly-derived mesenchymal cells (WJ-MSCs) to IPCs and compare them with a 2D cultured group. METHODS: The evaluation of cellular, molecular, and functional properties of differentiated cells on the 3D and 2D cultures was investigated by several assays such as electron microscopy, quantitative PCR, immunochemistry, western blotting, and ELISA. RESULTS: The in vitro studies showed that WJ-MSCs differentiated in the 3D culture have strong properties of IPCs such as islet-like cells. The expression of pancreatic-specific genes at both RNA and protein levels showed higher differentiation efficacy of 3D culture. Besides, the results of the ELISA tests demonstrate that in both groups the differentiated cells are functional and secreted C-peptide and insulin in glucose stimulation, but the secretion of C-peptide and insulin in the 3D culture group was higher than those cultured in 2D groups. CONCLUSION: Our findings showed the use of PCL/Fish gelatin nanofibrous scaffolds with optimized differentiation protocols can promote the differentiation of IPCs from WJ-MSCs compared to the 2D culture group.

Comparison of human-induced pluripotent stem cells and mesenchymal stem cell differentiation potential to insulin producing cells in 2D and 3D culture systems in vitro.

Diabetes is one of the most common diseases in the world that is chronic, progressive, and costly, and causes many complications. Common drug therapies are not able to cure it, and pancreas transplantation is not responsive to the high number of patients. The production of the insulin producing cells (IPCs) from the stem cells in the laboratory and their transplantation to the patient's body is one of the most promising new approaches. In this study, the differentiation potential of the induced pluripotent stem cells (iPSCs) and mesenchymal stem cells (MSCs) into IPCs was compared to each other while cultured on poly(lactic-co-glycolic) acid (PLGA)/polyethylene glycol (PEG) nanofibrous scaffold as a 3D substrate and tissue culture polystyrene (TCPS) as a 2D substrate. Although the expression level of the insulin, Glut2 and pdx-1 genes in stem cells cultured on 3D substrate was significantly higher than the stem cells cultured on 2D substrate, the highest expression level of these genes was detected in the iPSCs cultured on PLGA-PEG. Insulin and C-peptide secretions from differentiated cells were also investigated and the results showed that secretions in cultured iPSCs on the PLGA-PEG were significantly higher than cultured iPSCs on the TCPS and cultured MSCs on both PLGA-PEG and TCPS. In addition, insulin protein was also expressed in the cultured iPSCs on the PLGA-PEG significantly higher than cultured MSCs on the PLGA-PEG. It can be concluded that differentiation potential of iPSCs into IPCs is significantly higher than human MSCs at both 2D and 3D culture systems.

Improved osteogenic differentiation of human induced pluripotent stem cells cultured on polyvinylidene fluoride/collagen/platelet-rich plasma composite nanofibers.

Blood transfusion or blood products, such as plasma, have a long history in improving health, but today, platelet-rich plasma (PRP) is used in various medical areas such as surgery, orthopedics, and rheumatology in many ways. Considering the high efficiency of tissue engineering in repairing bone defects, in this study, we investigated the combined effect of nanofibrous scaffolds in combination with PRP on the osteogenic differentiation potential of human induced pluripotent stem cells (iPSCs). Electrospinning was used for fabricating nanofibrous scaffolds by polyvinylidene fluoride/collagen (PVDF/col) with and without PRP. After scaffold characterization, the osteoinductivity of the fabricated scaffolds was studied by culturing human iPSCs under osteogenic medium. The results showed that PRP has a considerable positive effect on the biocompatibility of the PVDF/col nanofibrous scaffold when examined by protein adsorption, cell attachment, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. In addition, the results obtained from alkaline phosphatase activity and calcium content assays demonstrated that nanofibers have higher osteoinductivity while grown on PRP-incorporated PVDF/col nanofibers. These results were also confirmed while the osteogenic differentiation of the iPSCs was more investigated by evaluating the most important bone-related genes expression level. According to the results, it can be concluded that PVDF/col/PRP has much more osteoinductivity while compared with the PVDF/col, and it can be introduced as a promising bone bio-implant for use in bone tissue engineering applications.

Retinoic acid and/or progesterone differentiate mouse induced pluripotent stem cells into male germ cells in vitro.

Numerous reagents were employed for differentiating induced pluripotent stem cells (iPSCs) into male germ cells; however, the induction procedure was ineffective. The aim of this study was to improve the in vitro differentiation of mice iPSCs (miPSCs) into male germ cells with retinoic acid (RA) and progesterone (P). miPSCs were differentiated to embryoid bodies (EBs) in suspension with RA with or without progesterone for 0, 4, and 7 days. Then, the expression of certain genes at different stages of male germ cell development including Ddx4 (pre meiosis), Stra8 (meiosis), AKAP3 (post meiosis), and Mvh protein was examined in RNA and/or protein levels by real-time polymerase chain reaction or flow cytometry, respectively. The Stra8 gene expression increased in the RA groups on all days. But, expression of this gene declined in RA + P groups. In addition, an increased expression of Ddx4 gene was observed on day 0 in the P group. Also, a significant upregulation was observed in the expression of AKAP3 gene in the RA + P group on days 0 and 4. However, gene expression decreased in P and RA groups on day 7. The expression of Mvh protein significantly increased in the RA group on day 7. The Mvh expression was also enhanced in the P group on day 4, but it decreased on day 7, while this protein upregulated on day 0 and 7 in the RA + P group. The miPSCs have the capacity for in vitro differentiation into male germ cells by RA and/or progesterone. However, the effects of these inducers depend on the type of combination and an effective time.

Decellularized amniotic membrane Scaffolds improve differentiation of iPSCs to functional hepatocyte-like cells.

Human-induced pluripotent stem cells-derived hepatocyte-like cells (hiPSCs-HLCs) holds considerable promise for future clinical personalized therapy of liver disease. However, the low engraftment of these cells in the damaged liver microenvironment is still an obstacle for potential application. In this study, we explored the effectiveness of decellularized amniotic membrane (dAM) matrices for culturing of iPSCs and promoting their differentiation into HLCs. The DNA content assay and histological evaluation indicated that cellular and nuclear residues were efficiently eliminated and the AM extracellular matrix component was maintained during decelluarization. DAM matrices were developed as three-dimensional scaffolds and hiPSCs were seeded into these scaffolds in defined induction media. In dAM scaffolds, hiPSCs-HLCs gradually took a typical shape of hepatocytes (polygonal morphology). HiPSCs-HLCs that were cultured into dAM scaffolds showed a higher level of hepatic markers than those cultured in tissue culture plates (TCPs). Moreover, functional activities in term of albumin and urea synthesis and CYP3A activity were significantly higher in dAM scaffolds than TCPs over the same differentiation period. Thus, based on our results, dAM scaffold might have a considerable potential in liver tissue engineering, because it can improve hepatic differentiation of hiPSCs which exhibited higher level of the hepatic marker and more stable metabolic functions.

Retinoic acid and 17ß-estradiol improve male germ cell differentiation from mouse-induced pluripotent stem cells.

This research aimed to explore the impacts of retinoic acid (RA)/17ß-estradiol (E) induction and embryoid body formation to enhance differentiation of mouse-induced pluripotent stem cells (miPSCs) into male germ cells in vitro. Flow cytometry and qPCR were conducted to describe miPSCs differentiation process. Various temporal expression profiles of germ cell-related genes were traced. Stra8 gene expression increased in the RA group on the 4th day compared to other groups. The RA group experienced a more significant increase than E group. The expression of Sycp3 increased in RA + E group on 4th day compared with other groups. Expression of AKAP3 enhanced in the RA + E group than other groups on day 4. Moreover, miPSCs showed that this gene expression in the RA + E group was increased in comparison to RA and E groups on day 7. AKAP3 gene expression on day 7 of miPSCs decreased in RA and E groups. Flow cytometry data indicated that 3%-8% of the cells in sub-G1 stage were haploid after RA and E induction compared to other groups on day 4. This study showed that miPSCs possess the power for differentiating into male germ cells in vitro via formation of embryoid body by RA with/or E induction.

Adipose-derived stem cells-conditioned medium improved osteogenic differentiation of induced pluripotent stem cells when grown on polycaprolactone nanofibers.

Considering that the common osteogenic growth factors cannot be transplanted with stem cells to the patients, many studies are underway to find a replacement for these factors. Recently, it has been determined that mesenchymal stem cell (MSC)-derived conditioned medium (CM) contains effective factors in the bone formation process. In the current study, the synergistic effect of adipose-derived MSC's CM, and polycaprolactone (PCL) scaffold was investigated on the osteogenic differentiation potential of human induced pluripotent stem cells (iPSCs). After scaffold fabrication by electrospinning and characterization by scanning electron microscopy, iPSCs proliferation in the presence of CM, PCL, and both was evaluated using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide. Then, iPSCs osteogenic differentiation was investigated while cultured on tissue culture plate and PCL under CM compared with the osteogenic medium using alizarin red staining, calcium content, alkaline phosphatase activity and gene and protein expression analysis. Proliferation rate of the iPSCs was increased while cultured under CM and its effect was synergistically enhanced by culture on PCL. Evaluation of the osteogenic markers was showed CM alone could induce osteogenic differentiation into the iPSCs and this potential was significantly increased while combined with PCL nanofibrous scaffold. According to the results, it was demonstrated that CM has an osteogenic induction property almost the same of the common osteogenic medium and it can also be used potentially with stem cells when transplant to the patients. CM can also help by prolonging cell survival at the site of the defect as well as accelerating healing process.

The role of microRNAs in embryonic stem cell and induced pluripotent stem cell differentiation in male germ cells.

New perspectives have been opened by advances in stem cell research for reproductive and regenerative medicine. Several different cell types can be differentiated from stem cells (SCs) under suitable in vitro and in vivo conditions. The differentiation of SCs into male germ cells has been reported by many groups. Due to their unlimited pluripotency and self-renewal, embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) can be used as valuable tools for drug delivery, disease modeling, developmental studies, and cell-based therapies in regenerative medicine. The unique features of SCs are controlled by a dynamic interplay between extrinsic signaling pathways, and regulations at epigenetic, transcriptional and posttranscriptional levels. In recent years, significant progress has been made toward better understanding of the functions and expression of specific microRNAs (miRNAs) in the maintenance of SC pluripotency. miRNAs are short noncoding molecules, which play a functional role in the regulation of gene expression. In addition, the important regulatory role of miRNAs in differentiation and dedifferentiation has been recently demonstrated. A balance between differentiation and pluripotency is maintained by miRNAs in the embryo and stem cells. This review summarizes the recent findings about the role of miRNAs in the regulation of self-renewal and pluripotency of iPSCs and ESCs, as well as their impact on cellular reprogramming and stem cell differentiation into male germ cells.

Comparison of osteogenic differentiation potential of induced pluripotent stem cells on 2D and 3D polyvinylidene fluoride scaffolds.

In recent decades, tissue engineering has been the most contributor for introducing 2D and 3D biocompatible osteoinductive scaffolds as bone implants. Polyvinylidene fluoride (PVDF), due to the unique mechanical strength and piezoelectric properties, can be a good choice for making a bone bioimplant. In the present study, PVDF nanofibers and film were fabricated as 3D and 2D scaffolds, and then, osteogenic differentiation potential of the human induced pluripotent stem cells (iPSCs) was investigated when grown on the scaffolds by evaluating the common osteogenic markers in comparison with tissue culture plate. Biocompatibility of the fabricated scaffolds was confirmed qualitatively and quantitatively by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and scanning electron microscopy assays. Human iPSCs cultured on PVDF nanofibers showed a significantly higher alkaline phosphate activity and calcium content compared with the iPSCs cultured on PVDF film. Osteogenic-related genes and proteins were also expressed in the iPSCs seeded on PVDF nanofibers significantly higher than iPSCs seeded on PVDF film, when investigated by real-time reverse transcription polymerase chain reaction and western blot analysis, respectively. According to the results, the PVDF nanofibrous scaffold showed a greater osteoinductive property compared with the PVDF film and due to the material similarity of the scaffolds, it could be concluded that the 3D structure could lead to better bone differentiation. Taken together, the obtained results demonstrated that human iPSC-seeded PVDF nanofibrous scaffold could be considered as a promising candidate for use in bone tissue engineering applications.

The role of nitric oxide signaling in renoprotective effects of hydrogen sulfide against chronic kidney disease in rats: Involvement of oxidative stress, autophagy and apoptosis.

The interplay between H2 S and nitric oxide (NO) is thought to contribute to renal functions. The current study was designed to assess the role of NO in mediating the renoprotective effects of hydrogen sulfide in the 5/6 nephrectomy (5/6 Nx) animal model. Forty rats were randomly assigned to 5 experimental groups: (a) Sham; (b) 5/6 Nx; (c) 5/6Nx+sodium hydrosulfide-a donor of H 2 S, (5/6Nx+sodium hydrosulfide [NaHS]); (d) 5/6Nx+NaHS+ L-NAME (a nonspecific nitric oxide synthase [NOS] inhibitor); (e) 5/6Nx+NaHS+aminoguanidine (a selective inhibitor of inducible NOS [iNOS]). Twelve weeks after 5/6 Nx, we assessed the expressions of iNOS and endothelial NOS (eNOS), oxidative/antioxidant status, renal fibrosis, urine N-acetyl-b-glucosaminidase (NAG) activity as the markers of kidney injury and various markers of apoptosis, inflammation, remodeling, and autophagy. NaHS treatment protected the animals against chronic kidney injury as depicted by improved oxidative/antioxidant status, reduced apoptosis, and autophagy and attenuated messenger RNA (mRNA) expression of genes associated with inflammation, remodeling, and NAG activity. Eight weeks Nω-nitro-l-arginine methyl ester ( L-NAME) administration reduced the protective effects of hydrogen sulfide. In contrast, aminoguanidine augmented the beneficial effects of hydrogen sulfide. Our finding revealed some fascinating interactions between NO and H 2 S in the kidney. Moreover, the study suggests that NO, in an isoform-dependent manner, can exert renoprotective effects in 5/6 Nx model of CKD.

Electrospun poly-l-lactic acid/polyvinyl alcohol nanofibers improved insulin-producing cell differentiation potential of human adipose-derived mesenchymal stem cells.

Combination of adipose-derived mesenchymal stem cells (ADSCs) and synthetic materials in terms of pancreatic tissue engineering can be considered as a treatment of diabetes. This study aimed to evaluate the differentiation of human ADSCs to pancreatic cells on poly-l-lactic acid/polyvinyl alcohol (PLLA/PVA) nanofibers as a three-dimensional (3D) scaffold. Mesenchymal stem cells (MSCs) were characterized for mesenchymal surface markers by flow cytometry. Then ADSCs were seeded on 3D scaffolds and treated with pancreatic differentiation medium. Immunostaining assay showed that ADSCs were very efficiently differentiated into a relatively homogeneous population of insulin-producing cells. Moreover, real-time RT-PCR results revealed that pancreas-specific markers were highly expressed in 3D scaffolds compared with their expression in tissue culture plates and this difference in expression level was significant. In addition, insulin and C-peptide secreted in response to varying concentrations of glucose in the 3D scaffold group was significantly higher than that in 2D culture. The results of the present study confirmed that PLLA/PVA scaffold seeded with ADSCs could be a suitable option in pancreatic tissue engineering.

Derivation of preoligodendrocytes from human-induced pluripotent stem cells through overexpression of microRNA 338.

MicroRNAs (miRNAs) control gene expression at the posttranscriptional level and have a critical role in many biological processes such as oligodendrocyte differentiation. Recent studies have shown that microRNA 338 (miR-338) is overexpressed during the oligodendrocyte development process in the central nervous system; this finding indicates a potentially important role for miR-338 in oligodendrocyte development. To evaluate this assumption, we studied the effect of miR-338 overexpression on promoting the differentiation of oligodendrocyte progenitor cells (OPCs), derived from human-induced pluripotent stem cells (hiPSC), into preoligodendrocyte. hiPSCs were differentiated into OPCs after treating for 16 days with basic fibroblast growth factor (BFGF), epidermal growth factor (FGF), and platelet-derived growth factor (PDGF)-AA. Bipolar OPCs appeared and the expression of OPC-related markers, including Nestin, Olig2, Sox10, PDGFRα, and A2B5 was confirmed by real-time polymerase chain reaction (PCR) and immunofluorescence. Then, OPCs were transduced by miR-338 expressing lentivirus or were treated with triiodothyronine (T3) for 6 days. Data obtained from real-time PCR and immunofluorescence experiment indicated that preoligodendrocyte markers such as Sox10, O4, and MBP were expressed at higher levels in transduced cells with miR-338 in comparison with the T3 group. So, the overexpression of miR-338 in iPSC-derived OPCs can promote their differentiation into preoligodendrocyte which can be used in cell therapy of myelin-related diseases.

Improved chondrogenic response of mesenchymal stem cells to a polyethersulfone/polyaniline blended nanofibrous scaffold.

Owing to the fact that the cartilage tissue is not able to repair itself, the treatment of the joint damages is very difficult by current methods. Induction of tissue repair requires suitable cell and extracellular matrix. Providing these two parts can only be done using tissue engineering. In the present study, polyethersulfone (PES) and polyaniline (PANI) blend was electrospined for nanofibrous scaffold fabrication. Mesenchymal stem cells were isolated from human adipose tissue (AT-MSCs), and after characterization cultured on the PES-PANI scaffold and culture plate. Electron microscopic and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assays were used for biocompatibility evaluation of the scaffold and the chondrogenic differentiation potential of AT-MSCs were investigated by staining of proteoglycans and gene and protein expression evaluation. Alcian blue staining, real-time reverse-transcriptase polymerase chain reaction and Western blot results showed that chondrogenic differentiation potential of AT-MSCs was significantly increased when grown on PES-PANI nanofibers and was compared to the one grown on a culture plate. According to the results, PES-PANI has a promising potential to be used as a biomedical implant in patients with joints lesion, such as arthritis and osteoarthritis.