Low dose Cold Atmospheric Plasma induces membrane oxidation, stimulates endocytosis and enhances uptake of nanomaterials in Glioblastoma multiforme cells

Abstract

Cold atmospheric plasma (CAP) has demonstrated synergistic cytotoxic effects with nanoparticles, especially promoting the uptake and accumulation of nanoparticles inside cells.However, the mechanisms driving the effects need to be explored. 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 (30 s, 75 kV). CAP treatment induces cellular membrane damage, mainly via lipid peroxidation as a result of reactive oxygen species (ROS) generation. Membranes rich in peroxidated 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. Our data 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 which will be useful for developing more efficient deliveries of nanoparticles and pharmaceuticals into cancer cells for tumour therapy and diagnosis. This mechanism of RONS-induced endocytosis will also be of relevance to other cancer therapies that induce an increase in extracellular RONS.

Efficacy of plasma activated saline in a co-culture infection control model

“…Lipid peroxidation in HaCaT cells was also not increased after exposure to three plasma devices in other studies, even if increase in DNA damage was detected 45 . In case of cancer cell lines such as melanoma and glioblastoma cells, PAM or direct exposure to plasma, respectively, caused an increase in the formation of MDA in cells 50 , 51 .…”

Acidified Nitrite Contributes to the Antitumor Effect of Cold Atmospheric Plasma on Melanoma Cells

“…Nevertheless, acidified nitrite was found to be strongly cytotoxic, indicating that molecular mechanisms independent of peroxynitrite exist and might also be involved in CAP effects. Another common feature of CAP is the induction of membrane damage in prokaryotic and eukaryotic cells [ 51 , 52 ]. Such alterations of the plasma membrane were previously used to improve drug delivery to cells and through tissues [ 53 ] but also have a potential role in antimicrobial and antitumor effects.…”

“…Interestingly, we could not detect increased membrane damage in response to treatment with acidified nitrite. A possible explanation can be found in the studies of He et al [ 52 , 54 ], which proposed ROS-dependent lipid peroxidation as the main cause of CAP-induced membrane damage. Our findings of strong cytotoxicity without membrane damage suggest that this process might not be a major contributor to CAP-induced killing of cancer cells.…”