Graphene/CuO₂ Nanoshuttles with Controllable Release of Oxygen Nanobubbles Promoting Interruption of Bacterial Respiration

Abstract

An oxygen nanoshuttle based on a reduced graphene oxide/copper peroxide (rGO/CuO 2 ) nanocomposite has been presented to deliver in situ oxygen nanobubbles (O 2 NBs) for combating bacterial infections. In the presence of rGO, the solid source of oxygen (i.e., CuO 2 ) was decomposed (in response to environmental conditions such as pH and temperature) into O 2 NBs in a more controllable and long-lasting trend (from 60 to 144 h). In a neutral buffer, the O 2 NBs experienced growth and collapse evolutions, creating a dynamic micro− nanoenvironment around the nanocomposite. In addition to effective battling against methicillin-resistant Staphylococcus aureus bacteria, the O 2 NBs demonstrated superior antibacterial properties on Gram-positive S. aureus to those on Gram-negative Escherichia coli bacteria, especially in the presence of rGO. In fact, the rGO contents could provide synergistic effects through harvesting some respiratory electrons (leading to striking interruption of the bacterial respiratory pathway) in one side and transferring them into the O 2 NBs, resulting in nanoscale reactive oxygen species (ROS) generation in another side. Moreover, nearinfrared laser irradiation induced more damage to the cell membrane due to the synergistic effects of local heat elevation and catalyzing the release/collapse of NBs imposing mechanical disruptions. Our results show that the O 2 -containing nanoshuttles can effectively be used as intelligent and controllable anti-infection nanorobots in upcoming graphene-based nanobiomedical applications.

Amplified antitumor efficacy by a targeted drug retention and chemosensitization strategy-based “combo” nanoagent together with PD-L1 blockade in reversing multidrug resistance

“…Notably, the viability of MCF7/Taxol cells treated with P@PTX-CuTCPP or P@PTX combined with a nontoxic dose of l -BSO was significantly lower than that of cells treated with P@PTX only, as shown in Fig. 4 C. Recent studies have demonstrated that Cu-involved nanomaterials have promising prospect in tumor theranostics [ 60 ], the antibacterial use [ 62 ] and bioimaging due to the generation of reactive oxygen species from Cu 2+ . In present study, although the low-dose use of Cu 2+ (up to 0.1 mM) alone failed to conquer tumor cells, we found that CuTCPP can be a synergist to enhance chemotherapy efficacy after encapsulaton into nanosystems.…”

Oriented Catalytic Oxidation Induced Fabrication of CuO/Mn3O4 Hierarchical Arrays as Binder‐Free Electrodes for High‐Performance Supercapacitor

“…[37] Specifically, the reaction mechanism of the proposed oriented catalytic oxidation process is illustrated in Figure 1d. When immersed in MnSO 4 aqueous solution containing H 2 O 2 , the Cu(OH) 2 nanorod template first reacts slowly with H 2 O 2 to produce CuO and low levels of O 2 (Equation І in Figure 1d and Figure S1a, Supporting Information), [38,39] in which O 2 can be exactly involved as a reactant, together with the sparse ionized OH − around the Cu(OH) 2 surfaces to directionally oxidize Mn 2+ to form Mn 3 O 4 on the nanorods (Table S1 and Figure S1b, Supporting Information, Equation ІІ in Figure 1d). [40] Immediately, such newly generated Mn 3 O 4 will serve as a catalyst to accelerate reaction І, leading to violent O 2 bubbles as well as rapid color variation of the arrays caused by the massive formation of CuO (Figures S2 and S3, Supporting Information).…”

Review of Oxygenation with Nanobubbles: Possible Treatment for Hypoxic COVID-19 Patients

“…In another example of the multipurpose role of ONBs, the Akhavan research group devised an efficient approach for the preparation of reduced graphene oxide (rGO)/copper peroxide (CuO 2 ) nanoshuttles that also allowed the controlled release of ONBs and simultaneously inhibited bacterial respiration. 217 The oxygen carrier comprised a solid source of oxygen CuO 2 and rGO as a carrier with a photothermal-sensitizing ability, to provide the needed oxygen in situ. Subsequently, laser irradiation was used to transfer the energy into localized heat, which damaged cell membranes and increased the release rate of the ONBs.…”

“…The solid and dashed lines represent scale bars of 1 μm and 500 nm, respectively. Reproduced with permission from ref ( 217 ). Copyright 2020 American Chemical Society.…”