Application of a stir-tank bioreactor for perfusion culture and continuous harvest of Glycyrrhiza inflata suspension cells

We developed a perfusion stir-tank bioreactor that allowed continuous cultivation and harvest of plant cells and challenged for Glycyrrhiza inflata cell suspensions. Continuous separation of cell cultures from the medium occurred using a gravitational sedimentation column. We then conducted cell retention studies of this bioreactor by detecting the cell loss in the discarded medium. We determined that complete cell retention had been achieved when the perfusion rate (perfusion rate is the ratio ofmedium feeding volume per day to bioreactor working volume) was lower than 100% d-1 and the cell suspension recirculation speed was more than 0.5 ml s-1. Growth kinetic measurements showed that the maximum cell concentration reached 25 ± 0.5 g l-1 DW (dry weight). The maximum growth rate occurred on Day 18. Under the given perfusion medium feed rate, the bioreactor operated smoothly, maintaining a relatively stable concentration of 20 g l-1 through continuous cell harvest. The bioreactorwe used could be an efficient cell culture system and demonstrates industrial potential

Epidermal Growth Factor Stimulates Cell Proliferation by Activating Voltage-Gated Potassium Channels in Rat Bone Marrow-Derived Mesenchymal Stem Cells

Poster PresentationBackground and objective: We have previously found that voltage-gated delayed rectifier potassium current (IKDR, encoded by Kv1.2 and Kv2.1) participated in regulation of cell cycling progression in rat mesenchymal stem cells (MSCs) from bone marrow. The present study was designed to investigate whether epidermal growth factor (EGF) regulates cell growth is mediated by activating IKDR. Methods: Whole-cell patch voltage-clamp, RT-PCR, Western blots, siRNA, cell proliferation assay were employed in the present study Results: EGF increased cell proliferation in a concentration-dependent manner, and the effect was countered by the broad spectrum protein tyrosine (PTK) inhibitor genistein and the EGFR kinase inhibitor AG556. We found that genistein and AG556 inhibited IKDR in a concentration-dependent manner, The protein tyrosine phosphatase (PTP) inhibitor orthovanadate enhanced IKDR, and counted the inhibitory effect of IKDR by genistein or AG556, suggesting the PTK-mediating modulation of IKDR. Interestingly EGF also increased IKDR, Downregulation of IKDR with siRNA targeting to Kv1.2 or Kv2.1 channels inhibited basal proliferation, and prevented EGF-stimulated proliferation in rat MSCs. Conclusion: These results demonstrate for the first time that EGF stimulates cell proliferation activating IKDR, and silencing Kv1.2 or Kv2.1 channels prevents the augmentation of proliferation by EFG, indicating that Kv1.2 and Kv2.1 channels mediate EGF effect in regulating cell growth in rat MSCs.published_or_final_versio

Decentralized adaptive pinning control for cluster synchronization of complex dynamical networks

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Fast-dissolving core-shell composite microparticles of quercetin fabricated using a coaxial electrospray process

This study reports on novel fast-dissolving core-shell composite microparticles of quercetin fabricated using coaxial electrospraying. A PVC-coated concentric spinneret was developed to conduct the electrospray process. A series of analyses were undertaken to characterize the resultant particles in terms of their morphology, the physical form of their components, and their functional performance. Scanning and transmission electron microscopies revealed that the microparticles had spherical morphologies with clear core-shell structure visible. Differential scanning calorimetry and X-ray diffraction verified that the quercetin active ingredient in the core and sucralose and sodium dodecyl sulfate (SDS) excipients in the shell existed in the amorphous state. This is believed to be a result of second-order interactions between the components; these could be observed by Fourier transform infrared spectroscopy. In vitro dissolution and permeation studies showed that the microparticles rapidly released the incorporated quercetin within one minute, and had permeation rates across the sublingual mucosa around 10 times faster than raw quercetin

Simulated tsunami inundation for a range of Cascadia megathrust earthquake scenarios at Bandon, Oregon, USA

Characterizations of tsunami hazards along the Cascadia subduction zone hinge on uncertainties in megathrust rupture models used for simulating tsunami inundation. To explore these uncertainties, we constructed 15 megathrust earthquake scenarios using rupture models that supply the initial conditions for tsunami simulations at Bandon, Oregon. Tsunami inundation varies with the amount and distribution of fault slip assigned to rupture models, including models where slip is partitioned to a splay fault in the accretionary wedge and models that vary the updip limit of slip on a buried fault. Constraints on fault slip come from onshore and offshore paleoseismological evidence. We rank each rupture model using a logic tree that evaluates a model\u27s consistency with geological and geophysical data. The scenarios provide inputs to a hydrodynamic model, SELFE, used to simulate tsunami generation, propagation, and inundation on unstructured grids with \u3c 5-15 m resolution in coastal areas. Tsunami simulations delineate the likelihood that Cascadia tsunamis will exceed mapped inundation lines. Maximum wave elevations at the shoreline varied from similar to 4 m to 25 m for earthquakes with 9-44 m slip and M-w 8.7-9.2. Simulated tsunami inundation agrees with sparse deposits left by the A. D. 1700 and older tsunamis. Tsunami simulations for large (22-30 m slip) and medium (14-19 m slip) splay fault scenarios encompass 80%-95% of all inundation scenarios and provide reasonable guidelines for landuse planning and coastal development. The maximum tsunami inundation simulated for the greatest splay fault scenario (3644 m slip) can help to guide development of local tsunami evacuation zones

Nanofibers Fabricated Using Triaxial Electrospinning as Zero Order Drug Delivery Systems

A new strategy for creating functional trilayer nanofibers through triaxial electrospinning is demonstrated. Ethyl cellulose (EC) was used as the filament-forming matrix in the outer, middle, and inner working solutions and was combined with varied contents of the model active ingredient ketoprofen (KET) in the three fluids. Triaxial electrospinning was successfully carried out to generate medicated nanofibers. The resultant nanofibers had diameters of 0.74 ± 0.06 μm, linear morphologies, smooth surfaces, and clear trilayer nanostructures. The KET concentration in each layer gradually increased from the outer to the inner layer. In vitro dissolution tests demonstrated that the nanofibers could provide linear release of KET over 20 h. The protocol reported in this study thus provides a facile approach to creating functional nanofibers with sophisticated structural features

A Thermal Management System to Reuse Thermal Waste Released by High-Power Light-Emitting Diodes

© 1963-2012 IEEE. In this article, a comprehensive and efficient thermal management system is proposed to harvest and reuse the thermal waste of high-power light-emitting diodes (HP-LEDs) for the first time. Besides a conventional cooling system, including a thermoelectric (TE) cooler (TEC), a heatsink, and a fan, the proposed thermal management system also employs a TE generator (TEG), a temperature sensor, a voltage boost converter, and a microcontroller for thermal waste recycling. In this system, some of the thermal waste released by the HP-LED is harvested by the TEG and converted into electrical energy. With the help of a voltage boost converter, the harvested electrical power is used to power a temperature sensor for monitoring the surface temperature of the HP-LED. The entire system is regulated by the microcontroller. The system is elaborately established, tested, and the results are discussed. The experimental results show that the proposed system has an output electrical power of approximately 696.5μW , which is used to power a temperature sensor as a demonstration. The sensor works well, and the discrepancy of the surface temperature of the HP-LED measured by the sensor and by a thermometer is less than 5.38%, which validates the proposed thermal management system

Stealth Polydopamine-Based Nanoparticles with Red Blood Cell Membrane for the Chemo-Photothermal Therapy of Cancer

Herein, we developed curcumin (Cur)-loaded porous poly(lactic-co-glycolic acid) (pPLGA) nanoparticles (NPs) by the nanoprecipitation method. Dopamine (DA) was then self-polymerized to form a polydopamine (PDA) layer on the surface of the NPs, yielding Cur@pPLGA/PDA NPs that are able to act as both chemotherapeutic and photothermal agents. These NPs were further camouflaged with the red blood cell membrane (RBCM) to construct RBCM-Cur@pPLGA/PDA NPs. The RBCM-pPLGA/PDA NPs were around 200 nm in size and demonstrated photothermal performance in the near-infrared (NIR) region, with a potent conversion efficiency (35.2%). The blank carrier has favorable cytocompatibility, but when drug loaded the NPs can efficiently induce the death of cancer cells (particularly when combined with NIR laser treatment). Cellular uptake results revealed greater in vitro uptake of RBCM-Cur@pPLGA/PDA NPs than bare Cur@pPLGA/PDA NPs in the case of cancer cells but reduced macrophage phagocytosis. In vivo studies in mice showed that the RBCM-Cur@pPLGA/PDA NPs exhibited prolonged blood circulation times and excellent photothermal properties, allowing tumor-specific chemo-photothermal therapy. The RBCM-Cur@pPLGA/PDA NP platform presents great potential for targeted synergistic cancer treatments

Widespread mitochondrial depletion via mitophagy does not compromise necroptosis

Programmed necrosis (or necroptosis) is a form of cell death triggered by the activation of receptor interacting protein kinase-3 (RIPK3). Several reports have implicated mitochondria and mitochondrial reactive oxygen species (ROS) generation as effectors of RIPK3-dependent cell death. Here, we directly test this idea by employing a method for the specific removal of mitochondria via mitophagy. Mitochondria-deficient cells were resistant to the mitochondrial pathway of apoptosis, but efficiently died via tumor necrosis factor (TNF)-induced, RIPK3-dependent programmed necrosis or as a result of direct oligomerization of RIPK3. Although the ROS scavenger butylated hydroxyanisole (BHA) delayed TNF-induced necroptosis, it had no effect on necroptosis induced by RIPK3 oligomerization. Furthermore, although TNF-induced ROS production was dependent on mitochondria, the inhibition of TNF-induced necroptosis by BHA was observed in mitochondria-depleted cells. Our data indicate that mitochondrial ROS production accompanies, but does not cause, RIPK3-dependent necroptotic cell death