Copper-Based Nanoparticles as Antimicrobials

Deposition of Copper on Poly(Lactide) Non-Woven Fabrics by Magnetron Sputtering—Fabrication of New Multi-Functional, Antimicrobial Composite Materials

“…In the light of continuous expansion of antibiotic resistance to bacteria, copper nanoparticles (CuNPs) with such attributes of copper as chemical stability (E 1 = 0.52 V) [ 36 ], developed surface and antibacterial prolonged antibacterial activity [ 37 ] (a very slow dissolution of metallic copper in water with subsequent formation of very poor soluble copper oxides Cu 2 O/CuO [ 37 ]), as well as a fair abrasion resistance of copper layer’s (hardness 230 kgf mm −2 ) [ 38 ], contrasted with their negligible contact toxicity toward animals [ 39 , 40 , 41 , 42 ], became a valuable alternative to traditional antibiotics [ 25 , 27 , 43 , 44 ]. The antibacterial activity of copper’s metallic surface is regarded as resulting from two supplemental mechanisms—surface–surface interaction of copper and bacteria (contact killing) and/or surface oxidation of copper with subsequent release of antibacterial cupric ions [ 25 , 27 , 43 , 44 , 45 , 46 , 47 , 48 ].…”

Antibacterial Cotton Fabric Functionalized with Copper Oxide Nanoparticles

“…On the basis of this definition, CuO NPs could be encompassed by the cytoplasmic membrane and form a vesicle that subsequently fuses with internal components in the cytoplasm. Conversely, the way of introduction to the cytoplasm by the direct diffusion of CuO NPs can be related to the adherence of these nanoparticles to the cytoplasmic membrane, and simultaneously with the generation of ROS on its surface that causes an increase in cell permeability, which leads to the uncontrolled transport of nanoparticles into the cell through this membrane [ 94 ]. Direct diffusion could also be due to the preference of CuO NPs toward the lipid head group or the tail (phospholipids) component of the cytoplasmic membrane, and this is related to their hydrophobic or hydrophilic nature [ 40 ].…”

“…Direct diffusion could also be due to the preference of CuO NPs toward the lipid head group or the tail (phospholipids) component of the cytoplasmic membrane, and this is related to their hydrophobic or hydrophilic nature [ 40 ]. Finally, nanoparticles being in the cytoplasm can bind to DNA molecules causing the helical structure disorganization, the inhibition of DNA replication, protein denaturation, and consequently cell death [ 92 , 94 ]. Apart from that and in parallel to this mechanism, CuO NPs could release ions and trigger the effects associated with them, which were previously discussed.…”

“…CuO NPs and Cu +2 ions induce the generation of ROS [ 40 , 62 , 87 , 97 ]. Moreover, it should be considered that, at a nanometer scale, there is a formation of more ROS per unit weight, and due to its excess production and disruption to the bacterial defense mechanisms, programmed cell death is activated, and triggers oxidative stress [ 40 , 94 ]. According to Bedlovicova et al oxidative stress is defined as a state when the equilibrium between the antioxidative defense of cell and oxidants is disrupted by the effect of excess of the oxidants such as ROS.…”

Biological relevance of CuFeO2 nanoparticles: Antibacterial and anti-inflammatory activity, genotoxicity, DNA and protein interactions

“…Even though few reports examine such effects, the copper(II)-iron(III) pairing in copper ferrite, CuFe2O4 NPs has shown enhanced antimicrobial response [12,13], while bioevaluation of copper(I)-iron(III) like the cuprous-ferric delafossite CuFeO2 NPs is absent apart from an antiviral study by Qui et al that showed promising results [14]. In contrast, cuprous counterpart Cu2O NPs is already established as a potential antimicrobial agent and also commercialized [15,16,17,18,19,20]. Generally, amongst the three oxidation states [metallic (Cu 0 ), cuprous (Cu +1 ), cupric (Cu +2 )], Cu(I) is the most reactive, being able to participate in both reductive and oxidative reactions due to similar redox potentials and has been shown to exhibit greater antimicrobial activity [14,18,20].…”