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L929 Fibroblasts (l929 + fibroblast)

Distribution by Scientific Domains

Polymers and Materials Science	66%

Selected Abstracts

Therapeutic Window for Bioactive Nanocomposites Fabricated by Laser Ablation in Polymer-Doped Organic Liquids,

ADVANCED ENGINEERING MATERIALS, Issue 5 2010
Anne Hahn
Abstract Polymeric nanomaterials are gaining increased interest in medical applications due to the sustained release of bioactive agents. Within this study nanomaterials are fabricated using laser ablation of silver and copper in polymer-doped organic liquids thus allowing to produce customized drug release systems. A strategy is shown to determine the therapeutic window for cells relevant for cochlear implant electrodes, defined by the viability of L929 fibroblasts, PC12 neuronal cells, and spiral ganglion cells on different concentrations of silver and copper ions. The distribution of nanoparticles within the silicone polymer matrix is determined using transmission electron microscopy. Hexane doped with 1% silicone resin is found to be an appropriate liquid matrix to fabricate a nanocomposite with a constant ion release rate. Silver ions of 10,µmol L,1 or copper ions of 100,µmol L,1 cause a suppression of tissue growth without inhibiting neuronal cell growth. The copper nanoparticle content of 0.1,wt% of the silicone composite releases ion concentrations which fit the therapeutic window. [source]

Stimulation of fibroblast proliferation by neokyotorphin requires Ca2+ influx and activation of PKA, CaMK II and MAPK/ERK

FEBS JOURNAL, Issue 2 2007
Olga V. Sazonova
Neokyotorphin [TSKYR, hemoglobin ,-chain fragment (137,141)] has previously been shown to enhance fibroblast proliferation, its effect depending on cell density and serum level. Here we show the dependence of the effect of neokyotorphin on cell type and its correlation with the effect of protein kinase A (PKA) activator 8-Br-cAMP, but not the PKC activator 4,-phorbol 12-myristate, 13-acetate (PMA). In L929 fibroblasts, the proliferative effect of neokyotorphin was suppressed by the Ca2+L -type channel inhibitors verapamil or nifedipine, the intracellular Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane- N,N,N,,N, - tetraacetic acid acetoxymethyl ester, kinase inhibitors H-89 (PKA), KN-62 (Ca2+/calmodulin-dependent kinase II) and PD98059 (mitogen-activated protein kinase). The proliferative effect of 8-Br-cAMP was also suppressed by KN-62 and PD98059. PKC suppression (downregulation with PMA or inhibition with bisindolylmaleimide XI) did not affect neokyotorphin action. The results obtained point to a cAMP-like action for neokyotorphin. [source]

Disulfide-Crosslinked Electrospun Poly(, -glutamic acid) Nonwovens as Reduction-Responsive Scaffolds

MACROMOLECULAR BIOSCIENCE, Issue 6 2009
Hiroaki Yoshida
Abstract Novel water-insoluble, and reduction-responsive nonwoven scaffolds were fabricated from , -PGA and tested in cell culture. An electrospinning method was developed to produce scaffolds of fibers with diameters of 0.05,0.5 µm. Crosslinking of the fibers with cystamine in the presence of EDC resulted in water-insoluble , -PGA nonwovens with disulfide crosslinkages. These crosslinked fibers were easily decomposed under physiological conditions using L -cysteine, a biocompatible reductant. In vitro experiments with mouse L929 fibroblasts showed good adhesion onto , -PGA-SS fiber matrices and excellent cell proliferation. These , -PGA-SS nonwovens can be used as novel biocompatible and biodegradable scaffolds with reduction-responsiveness for biomedical or tissue engineering applications. [source]

Phenolic Hydroxy Groups Incorporated for the Peroxidase-Catalyzed Gelation of a Carboxymethylcellulose Support: Cellular Adhesion and Proliferation

MACROMOLECULAR BIOSCIENCE, Issue 3 2009
Yuko Ogushi
Abstract The effect of Ph-OH group content on gelation time, mechanical properties, hydrophobicity, and cellular adhesiveness of hydrogels produced from carboxymethylcellulose derivatives is investigated. A higher Ph-OH group content induces faster gelation and yields more brittle and hydrophobic gels. After 4 h of seeding, a larger number of L929 fibroblasts adhere to the hydrogel of the CMC-Ph that contains 15.4 Ph-OH groups per 100 repeat units of uronic acid (97% adhesion rate) than to the gel of CMC-Ph with only 8.4 Ph-OH groups (62% adhesion rate). The results demonstrate that controlling the Ph-OH group content is an effective and useful way to control cellular adhesion and proliferation on the hydrogels, as well as gelation time and mechanical properties of the gels. [source]

Effect of immobilization of polysaccharides on the biocompatibility of poly(butyleneadipate- co -terephthalate) films

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 8 2010
Win-Chun Jao
Abstract Aiming to improve the hydrophilicity, antibacterial activity, cytocompatibility, and hemocompatibility of poly(butyleneadipate- co -terephthalate) (PBAT) films, PBAT films were treated with ozone, grafted with chitosan (CS), and followed by covalent immobilization of either heparin (HEP) or hyaluronic acid (HA). The surface graft density of modified PBAT films was detected by X-ray photoelectron spectroscopy (XPS) and dyeing. The surface roughness of PBAT films was measured using an atomic force microscope (AFM). After immobilizing CS, PBAT films acquired antibacterial activity against Staphylococcus aureus and Escherichia coli. The adsorption of human serum albumin (HSA) and human plasma fibrinogen (HPF) on PBAT,CS,HEP and PBAT,CS,HA films was lower compared to that of native PBAT. Moreover, HEP immobilization could effectively reduce platelet adhesion and prolong the blood coagulation time, thereby improving the blood compatibility of PBAT. In addition, the growth of L929 fibroblasts was improved for HEP or HA immobilized PBAT, suggesting this surface modification was non-cytotoxic. Furthermore, PBAT,CS,HEP and PBAT,CS,HA exhibited higher cell proliferation than native PBAT. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Ornithine decarboxylase activity of L929 cells after exposure to continuous wave or 50 Hz modulated radiofrequency radiation,a replication study

BIOELECTROMAGNETICS, Issue 7 2007
A. Höytö
Abstract A replication study with some extensions was made to confirm enhancement of ornithine decarboxylase (ODC) activity in murine L929 fibroblasts after radiofrequency (RF) field exposure reported in earlier studies. L929 cells purchased from two cell banks were exposed for 2, 8, or 24 h to continuous wave or DAMPS (burst modulated at 50 Hz, with 33% duty cycle) signals at specific absorption rate (SAR) levels of 2.5 or 6.0 W/kg. Exposures were carried out in Crawford and waveguide chambers, at frequencies 835 and 872 MHz, respectively. The results did not confirm findings of previous studies reporting increased ODC activity in RF-exposed cells. When Crawford cell exposure system was used, ODC activity was either not affected (in the case of 8 or 24 h exposures) or decreased after 2 h exposure at the highest SAR level (6 W/kg). The decrease was most pronounced when cooling with air flow was not used, and is most likely related to increased temperature. The minor methodological differences (use of antibiotics, increased sensitivity of ODC assay) are not likely to explain the inconsistency of the findings of the present and previous studies. Different results were obtained in experiments with the waveguide system that involves more efficient temperature control. In this exposure system, ODC activity was increased after 8 h exposure at 6 W/kg. Further studies are warranted to explore whether this finding reflects a true non-thermal effect. The present study did not provide evidence for modulation-specific effects reported in earlier studies. Bioelectromagnetics 28:501,508, 2007. © 2007 Wiley-Liss, Inc. [source]