75 research outputs found

    The Potential of N-Rich Plasma-Polymerized Ethylene (PPE:N) Films for Regulating the Phenotype of the Nucleus Pulposus

    Get PDF
    We recently developed a nitrogen-rich plasma-polymerized biomaterial, designated “PPE:N” (N-doped plasma-polymerized ethylene) that is capable of suppressing cellular hypertrophy while promoting type I collagen and aggrecan expression in mesenchymal stem cells from osteoarthritis patients. We then hypothesized that these surfaces would form an ideal substrate on which the nucleus pulposus (NP) phenotype would be maintained. Recent evidence using microarrays showed that in young rats, the relative mRNA levels of glypican-3 (GPC3) and pleiotrophin binding factor (PTN) were significantly higher in nucleus pulposus (NP) compared to annulus fibrosus (AF) and articular cartilage. Furthermore, vimentin (VIM) mRNA levels were higher in NP versus articular cartilage. In contrast, the levels of expression of cartilage oligomeric matrix protein (COMP) and matrix gla protein precursor (MGP) were lower in NP compared to articular cartilage. The objective of this study was to compare the expression profiles of these genes in NP cells from fetal bovine lumbar discs when cultured on either commercial polystyrene (PS) tissue culture dishes or on PPE:N with time. We found that the expression of these genes varies with the concentration of N ([N]). More specifically, the expression of several genes of NP was sensitive to [N], with a decrease of GPC3, VIM, PTN, and MGP in function of decreasing [N]. The expression of aggrecan, collagen type I, and collagen type II was also studied: no significant differences were observed in the cells on different surfaces with different culture time. The results support the concept that PPE:N may be a suitable scaffold for the culture of NP cells. Further studies are however necessary to better understand their effects on cellular phenotypes

    Changes in protein expression in mussels Mytilus galloprovincialis dietarily exposed to PVP/PEI coated silver nanoparticles at different seasons

    Get PDF
    Potential toxic effects of Ag NPs ingested through the food web and depending on the season have not been addressed in marine bivalves. This work aimed to assess differences in protein expression in the digestive gland of female mussels after dietary exposure to Ag NPs in autumn and spring. Mussels were fed daily with microalgae previously exposed for 24 hours to 10 µg/L of PVP/PEI coated 5 nm Ag NPs. After 21 days, mussels significantly accumulated Ag in both seasons and Ag NPs were found within digestive gland cells and gills. Two-dimensional electrophoresis distinguished 104 differentially expressed protein spots in autumn and 142 in spring. Among them, chitinase like protein-3, partial and glyceraldehyde-3-phosphate dehydrogenase, that are involved in amino sugar and nucleotide sugar metabolism, carbon metabolism, glycolysis/gluconeogenesis and the biosynthesis of amino acids KEGG pathways, were overexpressed in autumn but underexpressed in spring. In autumn, pyruvate metabolism, citrate cycle, cysteine and methionine metabolism and glyoxylate and dicarboxylate metabolism were altered, while in spring, proteins related to the formation of phagosomes and hydrogen peroxide metabolism were differentially expressed. Overall, protein expression signatures depended on season and Ag NPs exposure, suggesting that season significantly influences responses of mussels to NP exposure.This work has been funded by the Spanish Ministry of Economy and Competitiveness (NanoSilverOmics project MAT2012-39372), Basque Government (SAIOTEK project S-PE13UN142 and Consolidated Research Group GIC IT810-13) and the University of the Basque Country UPV/EHU (UFI 11/37 and PhD fellowship to N.D.). This study had also the support of Fundação para a Ciência e Tecnologia (FCT) from Portugal through the Strategic Project UID/MAH00350/2013 granted to CIMA. The contribution of K. Mehennaoui was possible within the project NanoGAM (AFR-PhD-9229040) and M. Mikolaczyk was supported by a PhD fellowship from the French Ministry of Higher Education and Research.info:eu-repo/semantics/acceptedVersio

    The Core Value Compass: visually evaluating the goodness of brands that do good

    Get PDF
    yesBrands that do good for the society as well as for themselves are motivated by the core values they espouse, which necessitates a better understanding of what qualities a true core value must possess. The inherent tension within brands that do good, between commercial interests to increase competitiveness, and societal interests that are closely linked to the brand’s authenticity, has largely been overlooked. Hence, we develop and demonstrate a relatively easy-to-apply visual tool for evaluating core values based on a set of ‘goodness’ criteria derived from extant theory. The Core Value Compass adopts a paradox-based, evolutionary perspective by incorporating the inherent tensions within true core values, and classifying them according to their temporal orientation. Thus, we contribute towards a better understanding of underlying tensions of core values and provide a practical tool that paves the way for improved, and indeed ethical, corporate branding strategies. Furthermore, we demonstrate the Compass’ application using the case of a public sector brand, which is a quintessential brand that does good. Therefore, we also contribute to the nascent theoretical discourse on public sector branding. This paper therefore adds to the notable attempts to bridge the gap between theory and practice in core values-based corporate branding
    corecore