Interaction of graphene family materials with <i>Listeria monocytogenes</i> and <i>Salmonella enterica</i>

Graphene family materials have unique properties, which make them valuable for a range of applications. The antibacterial properties of graphene have been reported; however, findings have been contradictory. This study reports on the antimicrobial proprieties of three different graphene materials (pristine graphene (pG), graphene oxide (GO), and reduced graphene oxide (rGO)) against the food-borne bacterial pathogens Listeria monocytogenes and Salmonella enterica. A high concentration (250 μg/mL) of all the analyzed graphenes completely inhibited the growth of both pathogens, despite their difference in bacterial cell wall structure. At a lower concentration (25 μg/mL), similar effects were only observed with GO, as growth inhibition decreased with pG and rGO at the lower concentration. Interaction of the nanoparticles with the pathogenic bacteria was found to differ depending on the form of graphene. Microscopic imaging demonstrated that bacteria were arranged at the edges of pG and rGO, while with GO, they adhered to the nanoparticle surface. GO was found to have the highest antibacterial activity

Nanoparticles containing allotropes of carbon have genotoxic effects on glioblastoma multiforme cells

The carbon-based nanomaterial family consists of nanoparticles containing allotropes of carbon, which may have a number of interactions with biological systems. The objective of this study was to evaluate the toxicity of nanoparticles comprised of pristine graphene, reduced graphene oxide, graphene oxide, graphite, and ultradispersed detonation diamond in a U87 cell line. The scope of the work consisted of structural analysis of the nanoparticles using transmission electron microscopy, evaluation of cell morphology, and assessment of cell viability by Trypan blue assay and level of DNA fragmentation of U87 cells after 24 hours of incubation with 50 μg/mL carbon nanoparticles. DNA fragmentation was studied using single-cell gel electrophoresis. Incubation with nanoparticles containing the allotropes of carbon did not alter the morphology of the U87 cancer cells. However, incubation with pristine graphene and reduced graphene oxide led to a significant decrease in cell viability, whereas incubation with graphene oxide, graphite, and ultradispersed detonation diamond led to a smaller decrease in cell viability. The results of a comet assay demonstrated that pristine graphene, reduced graphene oxide, graphite, and ultradispersed detonation diamond caused DNA damage and were therefore genotoxic in U87 cells, whereas graphene oxide was not