Browsing by Author "Nandkumar, AM"

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    Effect of tobacco extract on surfactant synthesis and its reversal by retinoic acid-role of cell-cell interactions in vitro
    (IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY-ANIMAL, 2013) George, UM; Ashna, U; Kumar, SSP; Nandkumar, AM
    Tobacco induces oxidative stress in the alveolar epithelium and causes its damage. Retinoic acid (RA) has a cardinal role in alveolar cell growth, differentiation, and maturation. The aim of the study was to investigate the role of cell-cell interactions and whether RA could reverse the effect of tobacco extract on epithelial function as expressed by surfactant synthesis. For this, an in vitro model, which provides multiple cell type interactions, as seen in vivo, was used. We had used the major lung cell types, alveolar epithelial and mesenchymal cells represented by the cell lines A549 (human lung adenocarcinoma cell line), and human fetal lung fibroblast-1 (HFL-1) for developing the monoculture and co-culture systems and studied the effect of tobacco extract and retinoic acid. The effect of tobacco and retinoic acid both singly and in combination on proliferation and surfactant synthesis was analyzed. Retinoic acid induced proliferation and upregulated surfactant synthesis in monocultures and co-cultures. Tobacco extract at 100 mu g/ml concentration decreased A549 proliferation and upregulated surfactant protein mRNA expression. In co-cultures treated with tobacco extract (100 mu g/ml), retinoic acid (1 mu M), regulated cell proliferation, and surfactant protein mRNA expression vis-A -vis the monoculture system. This clearly points to the fact that cell-cell interactions modulate the effect of additives or stimulants and help in assessing the in vivo combinatorial responses in vitro and that the retinoic acid effect is regenerative.
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    Hyaluronic acid-g-poly(HEMA) copolymer with potential implications for lung tissue engineering
    (CARBOHYDRATE POLYMERS, 2011) Radhakumary, C; Nandkumar, AM; Nair, PD
    Tissue engineering represents an attractive potential for regeneration of engineered functional pulmonary tissue. Hyaluronic acid, an extracellular matrix component promotes the growth and proliferation of most cells. The high water affinity of hyaluronic acid (HA) adversely affects its application in the field of tissue engineering. A copolymer of hyaluronic acid and poly(2-hydroxyethylmethacrylate). [poly(HEMA)] appeared as a good choice for the synthesis of a natural-synthetic polymer hybrid matrix with the synergistic properties of both the polymers like water stability and biocompatibility. The copolymer films were stable in water at both acidic and neutral pH in contrast to that of virgin HA films. Grafting significantly alters the mechanical properties of hyaluronic acid. The HA-g-poly(HEMA) is found to be non-cytotoxic to mammalian cells. Further, the polymer was analysed for supporting alveolar cell adhesion and growth and were found suitable for supporting multiple cell types with specific culture requirements. Thus, grafting with poly(HEMA) is a suitable method for the fabrication of stable, cytocompatible natural-synthetic polymer hybrid matrices for varied biomedical applications such as tissue engineering, wound dressings, drug delivery and so forth. (C) 2011 Elsevier Ltd. All rights reserved.
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    Immunomodulation by E. coli biofilms
    (INTERNATIONAL JOURNAL OF ANTIMICROBIAL AGENTS, 2013) Nandkumar, AM; Ss, PK