Browsing by Author "de Cortalezzi, Maria Fidalgo"

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    Effects of graphene oxide nanoparticles on the immune system biomarkers produced by RAW264.7 and human whole blood cell cultures
    (MDPI, 2018) Lategan, Kim; Alghadi, Hend; Bayati, Mohamed; de Cortalezzi, Maria Fidalgo; Pool, Edmund John
    Graphene oxide nanoparticles (GONPs) have attracted a lot of attention due to their many applications. These applications include batteries, super capacitors, drug delivery and biosensing. However, few studies have investigated the effects of these nanoparticles on the immune system. In this study, the in vitro effects of GONPs on the immune system was evaluated by exposing murine macrophages, RAW 264.7 cells and human whole blood cell cultures (to GONPs. The effects of GONPs on RAW cells were monitored under basal conditions. The whole blood cell cultures were exposed to GONPs in the presence or absence of the mitogens lipopolysaccharide (LPS) and phytohaemmagglutinin (PHA). A number of parameters were monitored for both RAWand whole blood cell cultures, these included cytotoxicity, inflammatory biomarkers, cytokines of the acquired immune system and a proteome profile analysis. The GONPs were cytotoxic to both RAW and whole blood cell cultures at 500 g/mL. In the absence of LPS, GONPs elicited an inflammatory response from the murine macrophage, RAW and whole blood cell cultures at 15.6 and 5 g/mL respectively. This activation was further corroborated by proteome profile analysis of both experimental cultures. GONPs inhibited LPS induced interleukin 6 (IL-6) synthesis and PHA induced interferon gamma (IFN ) synthesis by whole blood cell cultures in a dose dependent manner. In the absence of mitogens, GONPs stimulated IL-10 synthesis by whole blood cell cultures. The current study shows that GONPs modulate immune system biomarkers and that these may pose a health risk to individuals exposed to this type of nanoparticle.
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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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    The stability and anti-angiogenic properties of titanium dioxide nanoparticles (tio2nps) using caco-2 cells
    (MDPI, 2022) David, Oladipupo Moyinoluwa; Lategan, Kim Leigh; de Cortalezzi, Maria Fidalgo
    Titanium dioxide nanoparticles (TiO2NPs) are found in a wide range of products such as sunscreen, paints, toothpaste and cosmetics due to their white pigment and high refractive index. These wide-ranging applications could result in direct or indirect exposure of these NPs to humans and the environment. Accordingly, conflicting levels of toxicity has been associated with these NPs. Therefore, the risk associated with these reports and for TiO2NPs produced using varying methodologies should be measured. This study aimed to investigate the effects of various media on TiO2NP properties (hydrodynamic size and zeta potential) and the effects of TiO2NP exposure on human colorectal adenocarcinoma (Caco-2) epithelial cell viability, inflammatory and cell stress biomarkers and angiogenesis proteome profiles.