Hsyue-Jen Hsieh

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For long-term culture, murine adipose-derived stromal cells (mADSCs) at latter passages demonstrated a marked decline in proliferative activity, exhibited senescent morphology and reduced differentiation potentials, particularly osteogenesis. To extend the lifespan of mADSCs, two culture conditions containing hyaluronan (HA) was compared in our study, one(More)
Chitosan scaffolds were modified with RGDS (Arg-Gly-Asp-Ser) in the present work via an imide-bond forming reaction between amino groups in chitosan and carboxyl groups in peptides. Successful immobilization was verified with FTIR spectroscopy, and the immobilized amount was determined to be on the order of 10(-12) mol/cm2 through analysis of the(More)
Vascular endothelial cells (ECs) constantly experience fluid shear stresses generated by blood flow. Laminar flow is known to produce atheroprotective effects on ECs. Nrf2 is a transcription factor that is essential for the antioxidant response element (ARE)-mediated induction of genes such as heme-oxygenase 1 (HO-1). We previously showed that fluid shear(More)
OBJECTIVE The aim of this study was to fabricate a novel composite porous scaffold by blending chitosan and gamma-poly(glutamic acid) (gamma-PGA) for the sustained delivery of rhBMP-2. METHODS Chitosan and gamma-PGA were blended to fabricate a novel porous scaffold by the freeze-gelation method. For comparison, scaffolds made of freeze-dried chitosan,(More)
Freeze-fixation and freeze-gelation methods are presented in this paper which can be used to prepare highly porous scaffolds without using the time and energy consuming freeze-drying process. The porous structure was generated during the freeze of a polymer solution, following which either the solvent was extracted by a non-solvent or the polymer was gelled(More)
Endothelial cells (ECs) are constantly exposed to shear stress, the action of which triggers signaling pathways and cellular responses. During inflammation, cytokines such as IL-6 increase in plasma. In this study, we examined the effects of steady flow on IL-6-induced endothelial responses. ECs exposed to IL-6 exhibited STAT3 activation via phosphorylation(More)
A new technique using chitosan as support for covalent coupling of invertase via carbohydrate moiety improved the activity and thermal stability of immobilized invertase. The best preparation of immobilized invertase retained 91% of original specific activity (412 U mg−1). The half-life at 60 °C was increased from 2.3 h (free invertase) to 7.2 h(More)
Vascular endothelial cells (ECs) continuously experience hemodynamic shear stress generated from blood flow. Previous studies have demonstrated that shear stress modulates monocyte chemotactic protein-1 (MCP-1) expression in ECs. This study explored the roles of protein kinase C (PKC), extracellular signal-regulated protein kinase (ERK1/2), and nitric oxide(More)
The use of wheat germ agglutinin (WGA), a lectin molecule, to modify chitosan and enhance the cell-biomaterial interaction was examined. The percentage of living fibroblast cells on the surfaces of tissue culture polystyrene (TCPS) control, WGA-modified chitosan, and unmodified chitosan films increased to 99%, 99%, and 85%, respectively, after seeding for(More)
Gamma-poly(glutamic acid) (gamma-PGA), a hydrophilic and biodegradable polymer, was chosen to modify chitosan matrices to produce a gamma-PGA/chitosan composite biomaterial. Three types of both dense and porous composite matrices containing different amounts of gamma-PGA were fabricated. Chitosan and gamma-PGA matrices were also prepared as controls.(More)