Nafion and Polylysine treated PEDOT mammalian cell biosensor [article]

The present study describes a cell-based biosensor utilizing PEDOT electrodes coated with Nafion and polylysine for combined conductivity, cellular adhesion and proliferation. Neuroblastoma N2a cells were seeded on top of PEDOT electrodes treated with Nafion and Polylysine. Cellular attachment and viability were assayed and chronoamperometric measurements were taken to evaluate H202 toxicity. Cells exhibited relatively hight viability compared to those seeded in tissue culture plates. Chronoamperometric responses also provided preliminary evidence of the possible use of this assembly as a toxicity biosensor

Differential Screening of the Neurotoxicity of Insecticides by Means of a Novel Electrophysiological Biosensor

AbstractMore than 500 different organic chemical substances are used worldwide as pesticides in agriculture and veterinary science. There is increasing evidence that many of these compounds cause moderate to severe neurological damage, due to cytotoxic activity on the foetus or the adult. Conventional methods for assessing the neurotoxicity of pesticides and their residues are very elaborate, time-consuming and expensive. For this reason, a novel cell-based biosensory method has been developed, for the detection of pesticide residues based on the Bioelectric Recognition Assay, (BERA). Neuroblastoma N2a cells have been used, immobilized in calcium alginate gel in order to preserve their physiological functions. The avermectin abamectin was chosen as a model insecticide. Various operational parameters were investigated, such as assay temperature and electrode material. In its optimal configuration, the novel biosensor responded to different abamectin concentrations in a linear fashion, with satisfactory sensitivity (10 ppb) and at a considerably high speed (100-180sec). The selectivity of the assay against a pyrethroid insecticide, α- cypermethrin, was also validated

Nafion and Polylysine treated PEDOT mammalian cell biosensor [poster]

The present study describes a cell-based biosensor utilizing PEDOT electrodes coated with Nafion and Polylysine for combined conductivity, cellular adhesion and proliferation. Neuroblastoma N2a cells were seeded on top of PEDOT electrodes treated with Nafion and Polylysine. Cellular attachment and viability were assayed and chronoamperometric measurements were taken to evaluate H 202 toxicity. Cells exhibited relatively hight viability compared to those seeded in tissue culture plates. Chronoamperometric responses also provided preliminary evidence of the possible use of this assembly as a toxicity biosensor

Study of a cell-based electrochemical biosensor for fungicide cytotoxicity evaluation on mammalian cell lines

The ultimate concern over pesticides in the environment is their toxic impact on nontarget organisms, including humans. For over the last two decades, the toxicological research has focused on pesticide-induced oxidative stress in terms of monitoring alterations in various biochemical and molecular compositions. A relative new group of agricultural fungicides, strobilurins, represent a major class of plant protection products and world's largest selling fungicides. They act as complex III Qo site inhibitors and thus disrupt electron transport in the respiratory chain, which generates superoxide and potentially results in oxidative stress. Cell-based biosensors arise as powerful tools for the rapid detection of xenobiotics in food industries, agriculture and the environment. The present study was aimed at developing an electrochemical biosensor for cytotoxicity assays on mammalian cells, cultured on PEDOT electrodes. The cellular mono layers formed on top of the conductive material, support cell interactions, growth and metabolism as cells keep their original characteristics of morphology and functionality. In this framework, the action of kresoxim-methyl, of the stobilurins group, was examined on murine neuroblastoma cells (N2a). Square wave voltammetry (SWV) and a three-electrode configuration (W: PEDOT, C: Carbon, R: Silver) were used for recording the electrochemical changes after drug treatment. Moreover, standard viability/cytotoxicity protocols were conducted as references for assay comparisons. Due to PEDOTs transparent composition morphological observations and adhesion tests of the seeded cells were also made. Electrochemical responses against the fungicide provided evidence of the possible use of this assembly as a toxicity biosensor

Biochemical effects of comlex III Qo site respiratory chain inhibitor kresoxim-methyl on mammalian cells

The ultimate concern over pesticides in the environment is their toxic impact on nontarget organisms, including humans. For over the last two decades, the toxicological research has focused on pesticide-induced oxidative stress in terms of monitoring alterations in various biochemical and molecular compositions. A relative new group of agricultural fungicides, strobilurins, represent a major class of plant protection products and world's largest selling fungicides. They act as complex III Qo site inhibitors and thus disrupting electron transport in the respiratory chain. This electron leakage generates superoxide and potentially results in increased oxidative stress. The present study was aimed at investigating the biochemical mechanisms involved in the toxic action of kresoxim-methyl, a widely used agricultural fungicide of the stobilurins group on murine neuroblastoma cells (N2a)

Studies on the physiological function of in vitro produced antioxidants from sage (Salvia officinalis L.): Effects on cell growth and metabolism

We investigated the effect of antioxidant phenolic compounds produced by sage (Salvia officinalis) callus cultures on some physiological parameters of the producing cells. Although cultures demonstrated a continuous growth during an incubation period of five weeks, the cell dehydrogenase activity, the cytochrome c oxidase activity and the respiration of isolated mitochondria declined. An analysis of methanolic extracts derived from the callus pieces indicated that the accumulation of phenolic compounds was correlated with mitochondrial activity, although the antioxidant activity (Fe+2 reduction) of the extracts was independent from any other physiological parameter. These results might elucidate some aspects of the physiological function of in vitro produced phenolic antioxidants from sage. © 2002 by The Haworth Press, Inc. All rights reserved