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  • Enhanced chondrocyte densities on carbon nanotube composites: the combined role of nanosurface roughness and electrical stimulation. 18186050

    Simultaneous incorporation of intrinsic nanosurface roughness and external electrical stimulation may maximize the regeneration of articular cartilage tissue more than on nanosmooth, electrically nonstimulated biomaterials. Here, we report enhanced functions of chondrocytes (cartilage synthesizing cells) on electrically and nonelectrically stimulated highly dispersed carbon nanotubes (CNT) in polycarbonate urethane (PCU) compared to, respectively, stimulated pure PCU. Specifically, compared to conventional longitudinal (or vertical) electrical stimulation of chondrocytes on conducting surfaces which require high voltage, we developed a lateral electrical stimulation across CNT/PCU composite films of low voltage that enhanced chondrocyte functions. Chondrocyte adhesion and long-term cell densities (up to 2 days) were enhanced (more than 50%) on CNT/PCU composites compared to PCU alone without electrical stimulation. This study further explained why by measuring greater amounts of initial fibronectin adsorption (a key protein that mediates chondrocyte adhesion) on CNT/PCU composites which were more hydrophilic (than pure PCU) due to greater nanometer roughness. Importantly, the same trend was observed and was even significantly enhanced when chondrocytes were subjected to electrical stimulation (more than 200%) compared to nonstimulated CNT/PCU. For this reason, this study provided direct evidence of the positive role that conductive CNT/PCU films can play in promoting functions of chondrocytes for cartilage regeneration.
    Tipo de documento:
    Referencia
    Referencia del producto:
    AB2047
    Nombre del producto:
    Anti-Fibronectin Antibody

  • In vitro derivation of chondrogenic cells from human embryonic stem cells. 19907985

    Human embryonic stem cells (hESCs) have the ability to self-renew and differentiate into any cell lineage of the three germ layers, therefore holding great promise for regenerative medicine applications. However, directing lineage-restricted differentiation of hESCs and obtaining a homogenous differentiated cell population is still a challenge. We previously described a micromass culture system as a model system to study chondrogenic commitment of the hESCs. Using this system, various growth factors including BMP2 and TGFbeta1 direct chondrogenic differentiation and modulate cartilage-specific matrix gene expression in a distinctive manner. Furthermore, a high percentage of differentiated cells exhibit typical morphological characteristics of chondrocytes and express cartilage matrix proteins such as type II collagen and proteoglycans. Chondrogenic cells can be further isolated and cultured to form functional cartilage tissue in vitro. Here, we describe in detail our established protocols to analyze chondrogenic differentiation of hESCs, and possible isolation of chondrogenic cells to form functional cartilaginous tissue.
    Tipo de documento:
    Referencia
    Referencia del producto:
    MAB8887
    Nombre del producto:
    Anti-Collagen Type II Antibody, clone 6B3

  • Molecular analysis of the apoptotic effects of BPA in acute myeloid leukemia cells. 19538739

    BPA (bisphenol A or 2,2-bis(4-hydroxy-phenol)propane) is present in the manufacture of polycarbonate plastic and epoxy resins, which can be used in impact-resistant safety equipment and baby bottles, as protective coatings inside metal food containers, and as composites and sealants in dentistry. Recently, attention has focused on the estrogen-like and carcinogenic adverse effects of BPA. Thus, it is necessary to investigate the cytotoxicity and apoptosis-inducing activity of this compound.Cell cycle, apoptosis and differentiation analyses; western blots.BPA is able to induce cell cycle arrest and apoptosis in three different acute myeloid leukemias. Although some granulocytic differentiation concomitantly occurred in NB4 cells upon BPA treatment, the major action was the induction of apoptosis. BPA mediated apoptosis was caspase dependent and occurred by activation of extrinsic and intrinsic cell death pathways modulating both FAS and TRAIL and by inducing BAD phosphorylation in NB4 cells. Finally, also non genomic actions such as the early decrease of both ERK and AKT phosphorylation were induced by BPA thus indicating that a complex intersection of regulations occur for the apoptotic action of BPA.BPA is able to induce apoptosis in leukemia cells via caspase activation and involvement of both intrinsic and extrinsic pathways of apoptosis.
    Tipo de documento:
    Referencia
    Referencia del producto:
    06-599
    Nombre del producto:
    Anti-acetyl-Histone H3 Antibody

  • The impact of neonatal bisphenol-A exposure on sexually dimorphic hypothalamic nuclei in the female rat. 20696184

    Now under intense scrutiny, due to its endocrine disrupting properties, the potential threat the plastics component bisphenol-A (BPA) poses to human health remains unclear. Found in a multitude of polycarbonate plastics, food and beverage containers, and medical equipment, BPA is thought to bind to estrogen receptors (ERs), thereby interfering with estrogen-dependent processes. Our lab has previously shown that exposure to BPA (50mg/kg bw or 50μg/kg bw) during the neonatal critical period is associated with advancement of puberty, early reproductive senescence and ovarian malformations in female Long Evans rats. Here, using neural tissue obtained from the same animals, we explored the impact of neonatal BPA exposure on the development of sexually dimorphic hypothalamic regions critical for female reproductive physiology and behavior. Endpoints included quantification of oxytocin-immunoreactive neurons (OT-ir) in the paraventricular nucleus (PVN), serotonin (5-HT-ir) fiber density in the ventrolateral subdivision of the ventromedial nucleus (VMNvl) as well as ERα-ir neuron number in the medial preoptic area (MPOA), the VMNvl, and the arcuate nucleus (ARC). Both doses of BPA increased the number of OT-ir neurons within the PVN, but no significant effects were seen on 5-HT-ir fiber density or ERα-ir neuron number in any of the areas analyzed. In addition to hypothalamic development, we also assessed female sex behavior and body weight. No effect of BPA on sexual receptivity or proceptive behavior in females was observed. Females treated with BPA, however, weighed significantly more than control females by postnatal day 99. This effect of BPA on weight is critical because alterations in metabolism, are frequently associated with reproductive dysfunction. Collectively, the results of this and our prior study indicate that the impact of neonatal BPA exposure within the female rat hypothalamus is region specific and support the hypothesis that developmental BPA exposure may adversely affect reproductive development in females.
    Tipo de documento:
    Referencia
    Referencia del producto:
    Múltiplo
    Nombre del producto:
    Múltiplo

  • Nanotopographical cues augment mesenchymal differentiation of human embryonic stem cells. 23362187

    The production of bone-forming osteogenic cells for research purposes or transplantation therapies remains a significant challenge. Using planar polycarbonate substrates lacking in topographical cues and substrates displaying a nanotopographical pattern, mesenchymal differentiation of human embryonic stem cells is directed in the absence of chemical factors and without induction of differentiation by embryoid body formation. Cells incubated on nanotopographical substrates show enhanced expression of mesenchymal or stromal markers and expression of early osteogenic progenitors at levels above those detected in cells on planar substrates in the same basal media. Evidence of epithelial-to-mesenchymal transition during substrate differentiation and DNA methylation changes akin to chemical induction are also observed. These studies provide a suitable approach to overcome regenerative medical challenges and describe a defined, reproducible platform for human embryonic stem cell differentiation.
    Tipo de documento:
    Referencia
    Referencia del producto:
    AB5603
    Nombre del producto:
    Anti-Sox2 Antibody

  • Melanoma cells homing to the brain: an in vitro model. 25692137

    We developed an in vitro contact through-feet blood brain barrier (BBB) model built using type IV collagen, rat astrocytes, and human umbilical vein endothelial cells (HUVECs) cocultured through Transwell porous polycarbonate membrane. The contact between astrocytes and HUVECs was demonstrated by electron microscopy: astrocytes endfeet pass through the 8.0 μm pores inducing HUVECs to assume a cerebral phenotype. Using this model we evaluated transmigration of melanoma cells from two different patients (M1 and M2) selected among seven melanoma primary cultures. M2 cells showed a statistically significant higher capability to pass across the in vitro BBB model, compared to M1. Expression of adhesion molecules was evaluated by flow cytometry: a statistically significant increased expression of MCAM, αvβ3, and CD49b was detected in M1. PCR array data showed that M2 had a higher expression of several matrix metalloproteinase proteins (MMPs) compared to M1. Specifically, data suggest that MMP2 and MMP9 could be directly involved in BBB permeability and that brain invasion by melanoma cells could be related to the overexpression of many MMPs. Future studies will be necessary to deepen the mechanisms of central nervous system invasion.
    Tipo de documento:
    Referencia
    Referencia del producto:
    MAB1976F
    Nombre del producto:
    Anti-Integrin αVβ3 Antibody, clone LM609, FITC conjugated

  • Identification of process-localized mRNAs from cultured rodent hippocampal neurons. 17182790

    The regulated translation of localized mRNAs in neurons provides a mechanism for spatially restricting gene expression in a synapse-specific manner. To identify the population of mRNAs present in distal neuronal processes of rodent hippocampal neurons, we grew neurons on polycarbonate filters etched with 3 microm pores. Although the neuronal cell bodies remained on the top surface of the filters, dendrites, axons, and glial processes penetrated through the pores to grow along the bottom surface of the membrane where they could be mechanically separated from cell bodies. Quantitative PCR and immunochemical analyses of the process preparation revealed that it was remarkably free of somatic contamination. Microarray analysis of RNA isolated from the processes identified over 100 potentially localized mRNAs. In situ hybridization studies of 19 of these transcripts confirmed that all 19 were present in dendrites, validating the utility of this approach for identifying dendritically localized transcripts. Many of the identified mRNAs encoded components of the translational machinery and several were associated with the RNA-binding protein Staufen. These findings indicate that there is a rich repertoire of mRNAs whose translation can be locally regulated and support the emerging idea that local protein synthesis serves to boost the translational capacity of synapses.
    Tipo de documento:
    Referencia
    Referencia del producto:
    Múltiplo
    Nombre del producto:
    Múltiplo

  • Control of cultured human cells with femtosecond laser ablated patterns on steel and plastic surfaces. 23179464

    The purpose of the present study is to explore topographical patterns produced with femtosecond laser pulses as a means of controlling the behaviour of living human cells (U2OS) on stainless steel surfaces and on negative plastic imprints (polycarbonate). The results show that the patterns on both types of material strongly affect cell behaviour and are particularly powerful in controlling cell spreading/elongation, localization and orientation. Analysis by fluorescence and scanning electron microscopy shows that on periodic 1D grating structures, cells and cell nuclei are highly elongated and aligned, whereas on periodic 2D grid structures, cell spreading and shape is affected. The results also show that the density and morphology of the cells can be affected. This was observed particularly on pseudo-periodic, coral-like structures which clearly inhibited cell growth. The results suggest that these patterns could be used in a variety of applications among the fields of clinical research and implant design, as well as in diagnosis and in cell and drug research. Furthermore, this article highlights the noteworthy aspects and the unique strengths of the technique and proposes directions for further research.
    Tipo de documento:
    Referencia
    Referencia del producto:
    MAB3408
    Nombre del producto:
    Anti-Tubulin Antibody, beta, clone KMX-1

  • Paracellular permeability restricts airway epithelial responses to selectively allow activation by mediators at the basolateral surface. 17475869

    Respiratory pathogens and toxins often assault the lung from the airway lumen. Airway epithelia may initiate and amplify inflammation in response to these attacks, but under certain conditions confinement of inflammation to the airway lumen may be beneficial to the host. Accordingly, we hypothesized that airway epithelial polarity allows different responses to basolateral vs apical stimuli that may modulate inflammation. Using primary human airway epithelial cells differentiated at an air-liquid interface in culture, we found that responses to several cytokines required basolateral mediator application. In contrast, responses to Haemophilus influenzae occurred after either basolateral or apical interaction with airway epithelia. Experiments focused on IFN-gamma receptor polarity confirmed its predominant basolateral location in cultured airway epithelia as well as in normal human airway tissue. Furthermore, physical and pharmacologic disruption of barrier function in airway epithelia allowed responses to apical application of IFN-gamma and other cytokines. These in vitro studies directly correlated with experiments in mice in which an airway epithelial response to IFN-gamma injected into the airway lumen was seen only after disruption of barrier function. The results indicate that airway epithelia with intact barrier function restrict inflammatory responses by limitation of cell activation through requiring interaction of selected mediators with the basolateral surface. However, loss of barrier integrity allows epithelial responses to these mediators if located in the airway lumen to amplify airway defenses.
    Tipo de documento:
    Referencia
    Referencia del producto:
    07-224
    Nombre del producto:
    Anti-phospho-STAT2 (Tyr689) Antibody

  • Bovine caruncular epithelial cell line (BCEC-1) isolated from the placenta forms a functional epithelial barrier in a polarised cell culture model. 17850864

    In the bovine synepitheliochorial placenta key sites of fetal-maternal interaction are placentomes consisting of maternal caruncles interdigitating with fetal cotyledons. The aim of this study was to establish an epithelial cell line from caruncles of pregnant cows and to develop a model to study restricted trophoblast invasion, pathogenesis of pregnancy associated diseases and pathways of infection and transport. Primary epithelial cells were isolated, successfully subcultured for 32 passages and cryopreserved at various stages. The cultures were termed bovine caruncular epithelial cell line-1 (BCEC-1). Cytokeratin, zonula occludens-1 protein and vimentin but neither alpha-smooth muscle actin nor desmin were detected by immunofluorescence performed every 5 (+/-1) passages. These results were confirmed by Western blotting. BCEC-1 were then cultured either without matrix or on fibronectin or collagen coated Transwell polyester membrane inserts, respectively, enabling separate access to the basal or apical epithelial compartments. Transmission and scanning electron microscopy of BCEC-1 revealed ultrastructural features also observed in vivo, such as apical microvilli and junctional complexes. Transepithelial electrical resistance (TEER) was measured regularly and revealed an increase with advancing confluence in all cultures. Cultures on coated inserts reached confluence and corresponding TEER-levels at an earlier stage. In addition, the cells were tested negative for bovine virus diarrhoea (BVD) virus, but were permissive for the virus. In conclusion, the BCEC-1 cell line retained characteristics of maternal caruncular epithelial cells as observed in vivo and in primary cell cultures and thus will be a highly useful tool for future studies of pathways of invasion, fetal-maternal communication, transport and infection.
    Tipo de documento:
    Referencia
    Referencia del producto:
    AP189C
    Nombre del producto:
    Donkey Anti-Rat IgG Antibody, Cy3 conjugate, Species Adsorbed