High Hepatic Function Was Maintained on Electrospun Nanofibrous Scaffold

2007 ◽  
Vol 342-343 ◽  
pp. 197-200 ◽  
Author(s):  
Chang Hyun Ahn ◽  
Young Jin Kim ◽  
Inn Kyu Kang ◽  
Ga Young Jun ◽  
Young Gwang Ko ◽  
...  
Keyword(s):  
Cell Function ◽  
Cell Communication ◽  
Rat Hepatocytes ◽  
Average Diameter ◽  
Hepatic Function ◽  
Specific Cell ◽  
Nanofibrous Structure ◽  
Electrospinning Method ◽  
The Matrix

In this study, we prepared polystyrene (PS) nanofibers as hepatocytes culture substrates by electrospinning method and subsequently coated with specific ligand (poly(N--vinylbenzyl-- β-D-galactopyranosyl-(14)-D-gluconamide)(PVLA) for hepatocytes attachment. Rat hepatocytes’ behavior on the PVLA-coated and non-coated PS nanofibrous matrices have been investigated. Electrospun PS fiber structures revealed randomly aligned fibers with average diameter of 500 nm. Fabricated PS nanofibers had no bonding points like cotton fibers. Analyses by ATR/FTIR and ESCA revealed that PVLA was successfully coated to the surfaces of PS nanofibers. More hepatocytes were attached on the surface of PS nanofibers coated with PVLA than that on noncoated PS nanofibers. PS nanofibrous matrix could incorporate many cells into the interior of the matrix probably due to the suitable pore size. Cell viabilities cultured on PVLA-coated PS nanofibrous mats were maintained for 2 weeks, while it was decreased rapidly on PVLA-coated PS dishes. High hepatic function especially albumin secretion was maintained for 2 weeks on nanofibrous mats but rapidly decreased on flat PS dishes. These results indicate that nanofibrous structure enabled spheroid-like culture results in providing cell-cell communication and subsequent long-term maintenance of specific cell function.

Recent Advances in Biohybrid Materials for Tissue Engineering and Regenerative Medicine

2016 ◽  
Vol 04 (01) ◽  
pp. 1640001 ◽  
Author(s):  
Ying Wan ◽  
Xing Li ◽  
Shenqi Wang
Keyword(s):  
Tissue Engineering ◽  
Regenerative Medicine ◽  
Cell Function ◽  
Rapid Prototype ◽  
Artificial Organs ◽  
Specific Cell ◽  
Cell Matrix ◽  
Matrix Surface ◽  
The Matrix ◽  
Cell Matrix Interactions

Biohybrid materials play an important role in tissue engineering, artificial organs and regenerative medicine due to their regulation of cell function through specific cell–matrix interactions involving integrins, mostly those of fibroblasts and myofibroblasts, and ligands on the matrix surface, which have become current research focus. In this paper, recent progress of biohybrid materials, mainly including main types of biohybrid materials, rapid prototype (RP) technique for construction of 3D biohybrid materials, was reviewed in detail; moreover, their applications in tissue engineering, artificial organs and regenerative medicine were also reviewed in detail. At last, we address the challenges biohybrid materials may face.

Fabrication of cross-linked starch-based nanofibrous mat with optimized diameter

TAPPI Journal ◽  
2019 ◽  
Vol 18 (6) ◽  
pp. 381-389 ◽  
Author(s):  
ZAHRA ASHRAFI ◽  
SAEEDEH MAZINANI ◽  
ALI AKBAR GHAREHAGHAJI ◽  
LUCIAN LUCIA
Keyword(s):  
Starch Content ◽  
Electrospun Nanofibers ◽  
Average Diameter ◽  
Controlled Drug Release ◽  
Processing Parameters ◽  
Electrospinning Process ◽  
Design And Synthesis ◽  
Nanofibrous Structure ◽  
Electrospinning Method ◽  
Rsm Technique

The design and synthesis of natural and synthetic polymer blends have received recent and wide attention. These new biomaterials exhibit progress in properties required in the field of medicine and healthcare. Herein, the aim of present study is to fabricate starch (ST)/polyacrylic acid (PAA) electrospun nanofibrous mat with a smooth and uniform morphology, lowest fiber diameter (below 100 nm) and the highest possible starch content. Starch itself is poor in process-ability, and its electrospinning could be quite a challenging process. To address this, we carried out the response surface methodology (RSM) technique for modelling the electrospinning process. In order to have ST/PAA nanofibers with the finest possible diameter, optimized processing parameters (applied voltage, nozzle‐collector distance and feed rate) obtained from RSM technique were applied. ST/PAA electrospun nanofibers with an average diameter of 74±13 nm were successfully achieved via the electrospinning method for the first time. The structure, preparation and properties of the nanofibrous structure were discussed. Results indicated that drug loaded ST/PAA blend nanofibrous structure has a great potential to be used in controlled drug release systems.

scholarly journals Signal transduction-free radical modulation

2002 ◽  
Vol 21 (2) ◽  
pp. 69-84 ◽  
Author(s):  
Dusica Pavlovic ◽  
Vidosava Djordjevic ◽  
Gordana Kocic
Keyword(s):  
Oxidative Stress ◽  
Signal Transduction ◽  
Cell Function ◽  
Signal Transmission ◽  
Cell Signalling ◽  
Specific Cell ◽  
Phagocyte Nadph Oxidase ◽  
Cell Tissue ◽  
Numerous Cell

Signal transduction is the process of signal transmission from cell surface to cell interior. This ubiquitous mechanism enables functioning of general but also specific cell-tissue processes, involved in maintaining of cell homeostasis. Normal transduction processes disturbance represents the most frequent molecular basis in pathogenesis and complications of many diseases. Understanding of all sequences involved in signalling pathway cascades offers a possibility of different modulators application in therapeutic purposes. The activation of phagocyte NADPH oxidase is one of the best studied pathways of signal transduction. Meanwhile, reactive oxygen species generated in the process could modulate numerous cell transduction pathways. Diabetes mellitus may be associated with increase in oxidative stress, which may contribute to a long-term tissue damage. In addition to damage, oxidative stress can initiate cell signalling cascades that modulate cell function and finally could lead to the cell death. Hyperglicemia-induced activation of PKC-MAP kinase pathway has been now recognised as the key biochemical event in the pathogenesis of diabetic complications and insulin resistance.

Digital image processing methods applied to the study of annealing time on semiconductor-metal eutectic composites

1988 ◽  
Vol 46 ◽  
pp. 848-849
Author(s):  
J. Hefter
Keyword(s):  
Image Processing ◽  
Digital Image Processing ◽  
Digital Image ◽  
Electronic Device ◽  
Processing System ◽  
Average Diameter ◽  
Eutectic Solidification ◽  
Metal Silicide ◽  
The Matrix ◽  
Microscopic Studies

Semiconductor-metal composites, formed by the eutectic solidification of silicon and a metal silicide have been under investigation for some time for a number of electronic device applications. This composite system is comprised of a silicon matrix containing extended metal-silicide rod-shaped structures aligned in parallel throughout the material. The average diameter of such a rod in a typical system is about 1 μm. Thus, characterization of the rod morphology by electron microscope methods is necessitated.The types of morphometric information that may be obtained from such microscopic studies coupled with image processing are (i) the area fraction of rods in the matrix, (ii) the average rod diameter, (iii) an average circularity (roundness), and (iv) the number density (Nd;rods/cm2). To acquire electron images of these materials, a digital image processing system (Tracor Northern 5500/5600) attached to a JEOL JXA-840 analytical SEM has been used.

scholarly journals In Utero Exposure to Δ9-Tetrahydrocannabinol Leads to Postnatal Catch-Up Growth and Dysmetabolism in the Adult Rat Liver

2021 ◽  
Vol 22 (14) ◽  
pp. 7502
Author(s):  
Shelby L. Oke ◽  
Kendrick Lee ◽  
Rosemary Papp ◽  
Steven R. Laviolette ◽  
Daniel B. Hardy
Keyword(s):  
Mitochondrial Dysfunction ◽  
Animal Studies ◽  
Weight Ratio ◽  
Wistar Rat ◽  
Hepatic Function ◽  
Fetal Life ◽  
Adult Rat ◽  
Catch Up ◽  
By Catch

The rates of gestational cannabis use have increased despite limited evidence for its safety in fetal life. Recent animal studies demonstrate that prenatal exposure to Δ9-tetrahydrocannabinol (Δ9-THC, the psychoactive component of cannabis) promotes intrauterine growth restriction (IUGR), culminating in postnatal metabolic deficits. Given IUGR is associated with impaired hepatic function, we hypothesized that Δ9-THC offspring would exhibit hepatic dyslipidemia. Pregnant Wistar rat dams received daily injections of vehicular control or 3 mg/kg Δ9-THC i.p. from embryonic day (E) 6.5 through E22. Exposure to Δ9-THC decreased the liver to body weight ratio at birth, followed by catch-up growth by three weeks of age. At six months, Δ9-THC-exposed male offspring exhibited increased visceral adiposity and higher hepatic triglycerides. This was instigated by augmented expression of enzymes involved in triglyceride synthesis (ACCα, SCD, FABP1, and DGAT2) at three weeks. Furthermore, the expression of hepatic DGAT1/DGAT2 was sustained at six months, concomitant with mitochondrial dysfunction (i.e., elevated p66shc) and oxidative stress. Interestingly, decreases in miR-203a-3p and miR-29a/b/c, both implicated in dyslipidemia, were also observed in these Δ9-THC-exposed offspring. Collectively, these findings indicate that prenatal Δ9-THC exposure results in long-term dyslipidemia associated with enhanced hepatic lipogenesis. This is attributed by mitochondrial dysfunction and epigenetic mechanisms.

An Ultrasound Transducer by Lead Zirconate Titanate (PZT) Nanofibers

2011 ◽  
Author(s):  
Guitao Zhang ◽  
Yong Shi
Keyword(s):  
Lead Zirconate Titanate ◽  
Acoustic Waves ◽  
Average Diameter ◽  
Lead Zirconate ◽  
Ultrasound Transducer ◽  
Resonant Frequencies ◽  
Pulse Delay ◽  
Zirconate Titanate ◽  
Electrospinning Method ◽  
Assumed Mode

In this paper, we demonstrate Lead zirconate titanate (PZT) nanofibers as a transducer to generate and detect ultrasound acoustic waves. PZT nanofibers with average diameter of 102nm were fabricated by the electrospinning method. The as-fabricated nanofibers were collected and aligned across a 10 μm silicon trench with Au electrodes. After annealing, the device was tested with the pulse/delay method. Two resonant frequencies, 8 MHz and 13MHz, were detected respectively. By using the Hamilton’s principle for coupled electromechanical systems with properly assumed mode shape, the resonant frequency was caudated. Base on the current testing result, a broadband ultrasound transducer was envisioned.

The Relationship Between Magnetism and Microstructure of Ethylene Pyrolysis Furnace Tubes after a Long-term Service

2018 ◽  
Vol 24 (5) ◽  
pp. 478-487 ◽  
Author(s):  
Jingfeng Guo ◽  
Tieshan Cao ◽  
Congqian Cheng ◽  
Xianming Meng ◽  
Jie Zhao
Keyword(s):  
Saturation Magnetization ◽  
Outer Region ◽  
Cr Content ◽  
Pyrolysis Furnace ◽  
The Matrix ◽  
Furnace Tube ◽  
Primary Carbides ◽  
The Relationship ◽  
Very High

AbstractThe magnetism and microstructure of Cr25Ni35Nb and Cr35Ni45Nb alloy tubes after 5 years of service were investigated in this paper. The saturation magnetization of the Cr25Ni35Nb alloy tube in the thickness direction is more than 20 emu/g, and the tube becomes ferromagnetic. The inner and outer walls of Cr35Ni45Nb alloy tubes also become ferromagnetic. But the saturation magnetization of the Cr35Ni45Nb alloy tubes approaches to zero in the center zone. The primary carbides M7C3 and NbC are changed into M23C6 and G phase at the outer region of the furnace tube. However, the M23C6-type carbides were replaced by carbon-rich carbides M7C3 at the carburization zone. Cr-depleted zones are formed at the inner and outer walls of the furnace tubes owing to oxidation. Carburization and oxidation reduce the Cr content of the matrix. Accordingly, the saturation magnetization is very high at the carburization zone and Cr-depleted zone. The magnetism of Cr25Ni35Nb and Cr35Ni45Nb alloy tubes has a high correlation with the Cr content of the matrix. Carburization and oxidation are the main reasons that make the paramagnetic ethylene pyrolysis furnace tube change to ferromagnetic.

scholarly journals Deteriorating beta‐cell function in type 2 diabetes: a long‐term model

QJM ◽  
2003 ◽  
Vol 96 (4) ◽  
pp. 281-288 ◽  
Author(s):  
A. Bagust ◽  
S. Beale
Keyword(s):  
Type 2 Diabetes ◽  
Beta Cell ◽  
Beta Cell Function ◽  
Cell Function ◽  
Term Model

scholarly journals Minireview: The Neuroendocrine Regulation of Puberty: Is the Time Ripe for a Systems Biology Approach?

Endocrinology ◽  
2006 ◽  
Vol 147 (3) ◽  
pp. 1166-1174 ◽  
Author(s):  
Sergio R. Ojeda ◽  
Alejandro Lomniczi ◽  
Claudio Mastronardi ◽  
Sabine Heger ◽  
Christian Roth ◽  
...  
Keyword(s):  
Global Analysis ◽  
Single Gene ◽  
Functional Integration ◽  
Cell Communication ◽  
Cell Interaction ◽  
Specific Cell ◽  
Gnrh Secretion ◽  
Cell Functions ◽  
Hierarchical Arrangement ◽  
Cell Cell

The initiation of mammalian puberty requires an increase in pulsatile release of GnRH from the hypothalamus. This increase is brought about by coordinated changes in transsynaptic and glial-neuronal communication. As the neuronal and glial excitatory inputs to the GnRH neuronal network increase, the transsynaptic inhibitory tone decreases, leading to the pubertal activation of GnRH secretion. The excitatory neuronal systems most prevalently involved in this process use glutamate and the peptide kisspeptin for neurotransmission/neuromodulation, whereas the most important inhibitory inputs are provided by γ-aminobutyric acid (GABA)ergic and opiatergic neurons. Glial cells, on the other hand, facilitate GnRH secretion via growth factor-dependent cell-cell signaling. Coordination of this regulatory neuronal-glial network may require a hierarchical arrangement. One level of coordination appears to be provided by a host of unrelated genes encoding proteins required for cell-cell communication. A second, but overlapping, level might be provided by a second tier of genes engaged in specific cell functions required for productive cell-cell interaction. A third and higher level of control involves the transcriptional regulation of these subordinate genes by a handful of upper echelon genes that, operating within the different neuronal and glial subsets required for the initiation of the pubertal process, sustain the functional integration of the network. The existence of functionally connected genes controlling the pubertal process is consistent with the concept that puberty is under genetic control and that the genetic underpinnings of both normal and deranged puberty are polygenic rather than specified by a single gene. The availability of improved high-throughput techniques and computational methods for global analysis of mRNAs and proteins will allow us to not only initiate the systematic identification of the different components of this neuroendocrine network but also to define their functional interactions.

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