%0 Journal Article
%A Schickle, Karolina
%A Gołda-Cępa, Monika
%A Parlak Vuslat, Zümray
%A Grigorev, Nikita
%A Desante, Gaelle
%A Chlanda, Adrian
%A Mazuryk, Olga
%A Neuhaus, Kerstin
%A Schmidt, Christina
%A Amousa, NIma
%A Drozdz, Kamil
%A Neuss, Sabine
%A Pajerski, Wojciech
%A Esteves-Oliveira, Marcella
%A Brzychczy-Włoch, Monika
%A Kotarba, Andrzej
%A Gonzalez Julian, Jesus
%T Revealing bactericidal events on graphene oxide nano films deposited on metal implant surfaces
%J Journal of materials chemistry / B
%V 12
%N 10
%@ 2050-750X
%C London ˜[u.a.]œ
%I RSC
%M FZJ-2023-05115
%P 2494-2504
%D 2024
%X At a time when pathogens are developing strong resistance to antibiotics, ,the demand for microbe-killing surfaces on implants has increased significantly. To achieve this goal, profound understanding of the underlying mechanisms is crucial. We show that graphene oxide (GO) nano-films deposited on stainless steel (SS316L) exhibit superior antibacterial features. The physicochemical properties of GO itself have a crucial impact on the biological events and their diversity may account for the contradictory results reported elsewhere. However, essential properties of GO coatings, such as oxygen content and resulting electrical conductivity, have been overlooked so far. We hypothesized that the surface potential and electrical resistance of the oxygen content in the GO-nano films may induce bacteria-killing events on the conductive metallic substrates. In our study, GO applied contains 52 wt.% of oxygen, thus exhibits insulating properties. Deposited as nano-film on an electrical conducting steel substrate, GO flakes induce a Schottky-barrier in the interface, which, in consequence, inhibits the transfer of electrons to the conducting, underlying substrate. Deposited as nano-film on an electrical conducting steel substrate, GO flakes can induce Schottky-barrier in the interface, which, in consequence, inhibits the transfer of electrons to the conducting, underlying substrate. Consequently, this generates reactive oxygen species (ROS), resulting in bacteria-death. We confirmed the presence of GO coatings and their hydrolytic stability by using X-ray photoelectron spectroscopy (XPS) XPS, μRaman spectroscopy, scanning electron microscopy (SEM), and Kelvin probe force microscope (KPFM) measurements. The biological evaluation was performed on the MG63 osteoblast-like cell line and two elected bacteria species: S. aureus and P. aeruginosa, demonstrating both, cytocompatibility and antibacterial behavior of GO-coated SS316L substrates. We propose a two-step bactericidal mechanism: electron transfer from the bacteria membrane to the substrate, followed by ROS generation. This mechanism is supported by changes in contact angle, surface potential, and work function, identified as decisive factors.
%F PUB:(DE-HGF)16
%9 Journal Article
%$ 38170794
%U <Go to ISI:>//WOS:001135612500001
%R 10.1039/D3TB01854G
%U https://juser.fz-juelich.de/record/1019053