Browsing by Author "Pool, Edmund"

Now showing 1 - 6 of 6
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    The Assessment of Effects of Carbon Quantum Dots on Immune System Biomarkers Using RAW 264.7 Macrophage Cells
    (University of the Western Cape, 2020) Fowler, Jodi; Pool, Edmund
    Nanotechnology is a rapidly growing field of research. Due to major innovations brought about by developments in nanotech, several consumer products are currently available containing nanomaterials. The increase of nanomaterial production and use is accompanied by the increased potential of human, plant and animal exposure to these nanomaterials. As a relatively new nanomaterial, carbon quantum dots (CQDs) are being extensively used and researched due to its unique properties. Although many studies have assessed the toxic potential of CQDs, and found them to exhibit low toxicity, there is lack of work assessing the effects on the immune system. In the present study, RAW 264.7 murine macrophages were used as model to assess the immunomodulatory potential of CQDs. RAW cells exposed to varying concentrations of CQDs (0-500μg/ml), showed that CQDs caused a reduction at cell viability. In the absence of a mitogen CQDs, induced an inflammatory response by stimulating the release of various cytokines and chemokines such as, TNFα, MIP-1α, MIP-1β, MIP-2, IP-10, G-CSF, GM-CSF, and JE.
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    The effects of carbon dots on immune system biomarkers, using the Murine Macrophage cell line RAW 264.7 and human whole blood cell cultures
    (MDPI, 2018) Lategan, Kim; Fowler, Jodi; Bayati, Mohamed; Fidalgo de Cortalezzi, Maria; Pool, Edmund
    Abstract: Carbon dots (CDs) are engineered nanoparticles that are used in a number of bioapplications such as bioimaging, drug delivery and theranostics. The effects of CDs on the immune system have not been evaluated. The effects of CDs on the immune system were assessed by using RAW264.7 cells and whole blood cell cultures. RAW cells were exposed to CD concentrations under basal conditions. Whole blood cell cultures were exposed to CD concentrations under basal conditions or in the presence of the mitogens, lipopolysaccharide (LPS) or phytohaemmagglutinin (PHA). After exposure, a number of parameters were assessed, such as cell viability, biomarkers of inflammation, cytokine biomarkers of the acquired immune system and a proteome profile analysis. CDs were cytotoxic to RAW and whole blood cell cultures at 62.5, 250 and 500 µg/mL, respectively. Biomarkers associated with inflammation were induced by CD concentrations ≥250 and 500 µg/mL under basal conditions for both RAW and whole blood cell cultures, respectively. The humoral immune cytokine interleukin (IL)-10 was increased at 500 µg/mL CD under both basal and PHA activated whole blood cell culture conditions. Proteome analysis supported the inflammatory data as upregulated proteins identified are associated with inflammation. The upregulated proteins provide potential biomarkers of risk that can be assessed upon CD exposure.
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    Effects of graphene oxide nanoparticles on the immune system biomarkers produced by RAW 264.7
    (University of the Western Cape, 2019) Algadi, Hend Emhemed; Pool, Edmund; Fidalgo, M.
    Graphene oxide (GO) is a single carbon layer, oxygen bearing graphene derivative, containing hydroxyl and carboxyl groups. Graphene oxide nanoparticles (GONPs) are promising nanomaterials for a variety of applications such as electrochemical analysis, adsorption of biomolecules, biosensors and drug and vaccine delivery systems. While these newly engineered nanoparticles hold great potential for developments in industry and medicine, the widespread use of these material will inevitably result in GO residues in the environment where they could possibly pose a risk to human and wildlife health. Interaction of the nanoparticles and biota can affect numerous biological processes. In humans they can affect any of the physiological systems such as the immune, endocrine, reproductive and cardiovascular systems. Although studies have indicated that GO exposure cause increased reactive oxygen species in cells, they mechanisms whereby GO act on the cell are still poorly understood. A few studies have investigated the effects of GONP and other graphene nanoparticle derivatives on the immune system. The aim of this study was to investigate the in vitro effects of GONPs on the immune system by the exposure of the murine macrophage cell line, RAW 264.7, to different concentrations of GONPs.
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    The effects of titanium oxide nanoparticles on cultured cells and the immune system
    (University of Western Cape, 2021) Esterhuizen, Bevan Peter; Pool, Edmund
    Engineered nanomaterials derived from various bulk materials are being developed in ever larger quantities and with very diverse chemical compositions. The physical and chemical properties of the smaller nanoparticles are very different compared to their larger bulk chemicals. Titanium dioxide nanoparticles (TiO2NPs) are an example of such an engineered nanomaterial. Titanium dioxide nanoparticles are mainly used as a pigment in many applications such as glazes, enamels, plastics, pharmaceuticals, cosmetics, and it is widely used in sunscreens. Human exposure to TiO2NPs can occur both during manufacturing and use.
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    The identification of novel biomarkers in response to pollutant exposure using proteome profiler arrays
    (University of Western Cape, 2020) Leach, Lloyd Llewelyn; Pool, Edmund; Lategan, Kim; de Cortalezzi, Maria Fidalgo
    Nanotechnology is a rapidly expanding field with a multitude of practical uses namely textiles, cosmetics, agriculture, and health sciences. The focus, for the purposes of this thesis, will be on carbon dots. The small size and low surface-to-volume ratio result in different physico-chemical behaviour of these particles in comparison to its significantly larger bulk-produced counterparts.
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    Quantitative assessment of heavy metal effects on sperm function using computer‐aided sperm analysis and cytotoxicity assays
    (Wiley, 2018) Hardneck, Farren; Israel, Gadieja; Pool, Edmund; Maree, Liana
    One known environmental risk factor impacting on human reproduction is heavy metal pollution. Although some metals (e.g., Cu, Se and Zn) have protective effects on the male reproductive system in low doses, heavy metals can accumulate to toxic levels and result in poor semen quality and decreased sperm function. We investigated the effect of CuSO4 and CdCl2 (10, 50, 100 and 250 μg/ml or 500 μg/ml) on human sperm motility and vitality by using computer‐aided sperm analysis (CASA) and two cytotoxicity assays (WST‐1 and XTT). Several sperm motility parameters were significantly reduced after 5 hr of exposure to the highest concentrations of CuSO4 (250 μg/ml) and CdCl2 (500 μg/ml). The WST‐1 assay also revealed significantly lower absorbance values for 50, 100 and 250 μg/ml CuSO4 and for 500 μg/ml CdCl2; however, no significant effect was seen with XTT. The calculated average IC50 value was 50.31± 4.34 μg/ml for CuSO4 and 392.32 ±76.79 μg/ml for CdCl2. The effects of these metals were confirmed with MgCl2, a positive control. This study provides threshold concentrations for the harmful effect of CuSO4 and CdCl2 on human spermatozoa and recommends the use of WST‐1 as vitality assay in future in vitro studies.