• Cold Atmospheric Plasma Stimulates Clathrin-Dependent Endocytosis to Repair Oxidised Membrane and Enhance Uptake of Nanomaterial in Glioblastoma Multiforme Cells

      He, Zhonglei; Liu, Kangze; Scally, Laurence; Manaloto, Eline; Gunes, Sebnem; Ng, Sing Wei; Maher, Marcus; Tiwari, Brijesh K; Byrne, Hugh J.; Bourke, Paula; et al. (Springer Science and Business Media LLC, 2020-04-24)
      Cold atmospheric plasma (CAP) enhances uptake and accumulation of nanoparticles and promotes synergistic cytotoxicity against cancer cells. However, the mechanisms are not well understood. In this study, we investigate the enhanced uptake of theranostic nanomaterials by CAP. Numerical modelling of the uptake of gold nanoparticle into U373MG Glioblastoma multiforme (GBM) cells predicts that CAP may introduce a new uptake route. We demonstrate that cell membrane repair pathways play the main role in this stimulated new uptake route, following non-toxic doses of dielectric barrier discharge CAP. CAP treatment induces cellular membrane damage, mainly via lipid peroxidation as a result of reactive oxygen species (ROS) generation. Membranes rich in peroxidised lipids are then trafficked into cells via membrane repairing endocytosis. We confirm that the enhanced uptake of nanomaterials is clathrin-dependent using chemical inhibitors and silencing of gene expression. Therefore, CAP-stimulated membrane repair increases endocytosis and accelerates the uptake of gold nanoparticles into U373MG cells after CAP treatment. We demonstrate the utility of CAP to model membrane oxidative damage in cells and characterise a previously unreported mechanism of membrane repair to trigger nanomaterial uptake. This knowledge will underpin the development of new delivery strategies for theranostic nanoparticles into cancer cells.
    • Fructooligosaccharides integrity after atmospheric cold plasma and high-pressure processing of a functional orange juice

      Lima Almeida, Francisca Diva; Gomes, Wesley Faria; Cavalcante, Rosane; Tiwari, Brijesh K; Cullen, Patrick J.; Frias, Jesus; Bourke, Paula; Fernandes, Fabiano A.N.; Rodrigues, Sueli; National Council of Technological and Scientific Development (Elsevier, 2017-10-02)
      In this study, the effect of atmospheric pressure cold plasma and high-pressure processing on the prebiotic orange juice was evaluated. Orange juice containing 7 g/100 g of commercial fructooligosaccharides (FOS) was directly and indirectly exposed to a plasma discharge at 70 kV with processing times of 15, 30, 45 and 60 s. For high-pressure processing, the juice containing the same concentration of FOS was treated at 450 MPa for 5 min at 11.5 °C in an industrial equipment (Hyperbaric, model: 300). After the treatments, the fructooligosaccharides were qualified and quantified by thin layer chromatography. The organic acids and color analysis were also evaluated. The maximal overall fructooligosaccharides degradation was found after high-pressure processing. The total color difference was < 3.0 for high-pressure and plasma processing. citric and ascorbic acid (Vitamin C) showed increased content after plasma and high-pressure treatment. Thus, atmospheric pressure cold plasma and high-pressure processing can be used as non-thermal alternatives to process prebiotic orange juice.