Browsing by Author "Wang, Chien-Ying"

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Development of a Graphene Oxide-Incorporated Polydimethylsiloxane Membrane with Hexagonal Micropillars
(2018-09-01)
Lin, Yi-Ying
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Chien, Yueh
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Chuang, Jen-Hua
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Chang, Chia-Ching
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Yang, Yi-Ping
Several efforts have been made on the development of bioscaffolds including the polydimethylsiloxane (PDMS) elastomer for supporting cell growth into stable sheets. However, PDMS has several disadvantages, such as intrinsic surface hydrophobicity and mechanical strength. Herein, we generated a novel PDMS-based biomimetic membrane by sequential modifications of the PMDS elastomer with graphene oxide (GO) and addition of a hexagonal micropillar structure at the bottom of the biomembrane. GO was initially homogenously mixed with pure PDMS and then was further coated onto the upper surface of the resultant PDMS. The elastic modulus and hydrophilicity were significantly improved by such modifications. In addition, the development of hexagonal micropillars with smaller diameters largely improved the ion permeability and increased the motion resistance. We further cultured retinal pigment epithelial (RPE) cells on the surface of this modified PDMS biomembrane and assayed its biocompatibility. Remarkably, the GO incorporation and coating exhibited beneficial effect on the cell growth and the new formation of tight junctions in RPE cells. Taken together, this GO-modified PDMS scaffold with polyhexagonal micropillars may be utilized as an ideal cell sheet and adaptor for cell cultivation and can be used in vivo for the transplantation of cells such as RPE cells.
Enhanced Antioxidant Capacity of Dental Pulp-Derived iPSC-Differentiated Hepatocytes and Liver Regeneration by Injectable HGF-Releasing Hydrogel in Fulminant Hepatic Failure
(2015-01-01)
Chiang, Chih-Hung
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Wu, Wai-Wah
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Li, Hsin-Yang
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Chien, Yueh
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Sun, Cho-Chin
Acute hepatic failure (AHF) is a severe liver injury leading to sustained damage and complications. Induced pluripotent stem cells (iPSCs) may be an alternative option for the treatment of AHF. In this study, we reprogrammed human dental pulp-derived fibroblasts into iPSCs, which exhibited pluripotency and the capacity to differentiate into tridermal lineages, including hepatocyte-like cells (iPSC-Heps). These iPSC-Heps resembled human embryonic stem cell-derived hepatocyte-like cells in gene signature and hepatic markers/functions. To improve iPSC-Heps engraftment, we next developed an injectable carboxymethyl-hexanoyl chitosan hydrogel (CHC) with sustained hepatocyte growth factor (HGF) release (HGF CHC) and investigated the hepatoprotective activity of HGF CHC-delivered iPSC-Heps in vitro and in an immunocompromised AHF mouse model induced by thioacetamide (TAA). Intrahepatic delivery of HGF CHC iPSC-Heps reduced the TAA-induced hepatic necrotic area and rescued liver function and recipient viability. Compared with PBS-delivered iPSC-Heps, the HGF CHC-delivered iPSC-Heps exhibited higher antioxidant and antiapoptotic activities that reduced hepatic necrotic area. Importantly, these HGF CHC-mediated responses could be abolished by administering anti-HGF neutralizing antibodies. In conclusion, our findings demonstrated that HGF mediated the enhancement of iPSC-Hep antioxidant/antiapoptotic capacities and hepatoprotection and that HGF CHC is as an excellent vehicle for iPSC-Hep engraftment in iPSC-based therapy against AHF.
Enhancing induced pluripotent stem cell toward differentiation into functional cardiomyocytes
(2020-07-01)
Chien, Chian-Shiu
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Wang, Chien-Ying
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Leu, Hsin-Bang
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Chien, Yueh
;
Yang, Yi-Ping
Background: Heart diseases, especially myocardial ischemia, remain one of the leading causes of mortality worldwide and usually result in irreparable cardiomyocyte damage and severe heart failure. Recent advances in induced pluripotent stem cell (iPSC) technologies for applied regenerative medicine and stem cell research, especially for iPSC-derived cardiomyocytes have increased the hope for heart repair. However, the driver molecules of myocardial differentiation and the functional reconstruction capacity of iPSC-derived cardiomyocytes are still questionable. Methods: Herein, we established a rapid differentiated platform that is involved in cardiomyogenic differentiation and maturation from iPSCs in vitro. Functional analysis is performed in miR-181a-transfected iPSC-derived cardiomyocyte (iPSC-cardio/miR-181a) under a time-lapse microscope. In addition, we calculated the beating area and frequency of iPSC-cardio/miR-181a cells in the presence of HCN4 shRNA or miR-181a SPONGE. Results: miR-181a enhanced the beating area and maintained the beating frequency of iPSC-derived cardiomyocytes by enhancing HCN4 expression. Conclusion: miR-181a would play a key role on maintaining proper beating function in iPSC-derived cardiomyocytes.
Imbalanced Production of Reactive Oxygen Species and Mitochondrial Antioxidant SOD2 in Fabry Disease-Specific Human Induced Pluripotent Stem Cell-Differentiated Vascular Endothelial Cells
(2017-01-01)
Tseng, Wei-Lien
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Chou, Shih-Jie
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Chiang, Huai-Chih
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Wang, Mong-Lien
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Chien, Chian-Shiu
Fabry disease (FD) is an X-linked inherited lysosomal storage disease caused by alpha-galactosidase A (GLA) deficiency. Progressive intracellular accumulation of globotriaosylceramide (Gb3) is considered to be pathogenically responsible for the phenotype variability of FD that causes cardiovascular dysfunction; however, molecular mechanisms underlying the impairment of FD-associated cardiovascular tissues remain unclear. In this study, we reprogrammed human induced pluripotent stem cells (hiPSCs) from peripheral blood cells of patients with FD (FD-iPSCs); subsequently differentiated them into vascular endothelial-likecells (FD-ECs) expressing CD31, VE-cadherin, and vWF; and investigated their ability to form vascular tube-like structures. FD-ECs recapitulated the FD pathophysiological phenotype exhibiting intracellular Gb3 accumulation under a transmission electron microscope. Moreover, compared with healthy control iPSC-derived endothelial cells (NC-ECs), reactive oxygen species (ROS) production considerably increased in FD-ECs. Microarray analysis was performed to explore the possible mechanism underlying Gb3 accumulation-induced ROS production in FD-ECs. Our results revealed that superoxide dismutase 2 (SOD2), a mitochondrial antioxidant, was significantly downregulated in FD-ECs. Compared with NC-ECs, AMPK activity was significantly enhanced in FD-ECs. Furthermore, to investigate the role of Gb3 in these effects, human umbilical vein endothelial cells (HUVECs) were treated with Gb3. After Gb3 treatment, we observed that SOD2 expression was suppressed and AMPK activity was enhanced in a dose-dependent manner. Collectively, our results indicate that excess accumulation of Gb3 suppressed SOD2 expression, increased ROS production, enhanced AMPK activation, and finally caused vascular endothelial dysfunction. Our findings suggest that dysregulated mitochondrial ROS may be a potential target for treating FD.
Using cationic polyurethane-short branch PEI as microRNA-driven nano-delivery system for stem cell differentiation
(2020-04-01)
Chien, Chian-Shiu
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Wang, Chien-Ying
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Yang, Yi-Ping
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Chou, Shih-Jie
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Ko, Yu-Ling
Background: Non-viral gene delivery, such as using biodegradable polyurethane short-branch polyethylenimine (PU-PEI), has been considered a potentially safer gene delivery system in comparison to conventional virus systems. Methods: The polycationization of DNA complexes protects DNA from nuclease degradation, and these DNA complexes are nanoscale in size to enter the cell through endocytosis. Results: Due to the net positive surface charge of the cell, these polyplexes efficiently bind to the cell through electrostatic interactions with negatively charged membrane components. Cationic PU-PEI has been shown to be non-cytotoxic and has a high transfection efficiency, making it a practical gene delivery material in diseases. Conclusion: We developed a PU-PEI nanomedicine-based platform to efficiently deliver microRNA in promoting differentiation capacity of stem cells, especially on induced pluripotent stem cells.