Dual UV irradiation-based metal oxide nanoparticles for enhanced antimicrobial activity in <em>Escherichia coli</em> and M13 bacteriophage

Abstract

Metal oxide (MO) nanoparticles have been studied as nano-antibiotics due to their antimicrobial activities even in antibiotic-resistant microorganisms. We hypothesized that a hybrid system of dual UV irradiation and MO nanoparticles would have enhanced antimicrobial activities compared with UV or MO nanoparticles alone. In this study, nanoparticles of ZnO, ZnTiO 3 , MgO, and CuO were selected as model nanoparticles. A dual UV collimated beam device of UV-A and UV-C was developed depending upon the lamp divided by coating. Physicochemical properties of MO nanoparticles were determined using powder X-ray diffractometry (PXRD), Brunauer-Emmett-Teller analysis, and field emission-scanning electron microscopy with energy-dispersive X-ray spectroscopy. Atomic force microscopy with an electrostatic force microscopy mode was used to confirm the surface topology and electrostatic characteristics after dual UV irradiation. For antimicrobial activity test, MO nanoparticles under dual UV irradiation were applied to Escherichia coli and M13 bacteriophage (phage). The UV-A and UV-C showed differential intensities in the coated and uncoated areas (UV-A, coated = uncoated; UV-C, coated ≪ uncoated). MO nanoparticles showed sharp peaks in PXRD patterns, matched to pure materials. Their primary particle sizes were less than 100 nm with irregular shapes, which had an 8.6~25.6 m 2 /g of specific surface area with mesopores of 22~262 nm. The electrostatic properties of MO nanoparticles were modulated after UV irradiation. ZnO, MgO, and CuO nanoparticles, except ZnTiO 3 nanoparticles, showed antibacterial effects on E. coli . Antimicrobial effects on E. coli and phages were also enhanced after cyclic exposure of dual UV and MO nanoparticle treatment using the uncoated area, except ZnO nanoparticles. Our results demonstrate that dual UV-MO nanoparticle hybrid system has a potential for disinfection. We anticipate that it can be developed as a next-generation disinfection system in pharmaceutical industries and water purification systems.

<p>Photocatalytic antibacterial application of zinc oxide nanoparticles and self-assembled networks under dual UV irradiation for enhanced disinfection</p>

“…1,2 They have been highlighted as natural alternatives to TiO 2 nanoparticles in various research fields such as photocatalysis and energy storage. 2,3,23 Among the bioapplications of ZnO nanoparticles, [4][5][6][7][8][9][10][11][12][13] they have been reported to be photocatalytic antibiotics against bacteria and phages. 5,6,[8][9][10][11][12][13] For general antimicrobial therapy, ZnO nanoparticles also demonstrated therapeutic potential in human pathogens (minimum inhibitory concentration values: 30-80 µg/mL), suggesting the possibility of their use as combination agents with other antibiotics such as cefotaxime and ceftriaxon.…”

“…2,3,23 Among the bioapplications of ZnO nanoparticles, [4][5][6][7][8][9][10][11][12][13] they have been reported to be photocatalytic antibiotics against bacteria and phages. 5,6,[8][9][10][11][12][13] For general antimicrobial therapy, ZnO nanoparticles also demonstrated therapeutic potential in human pathogens (minimum inhibitory concentration values: 30-80 µg/mL), suggesting the possibility of their use as combination agents with other antibiotics such as cefotaxime and ceftriaxon. 5,[8][9][10][11][12][13] In the present study, the enhanced antibacterial activities of dual UV-irradiated ZnO nanoparticles and multilevel porous networks on Si wafers against E. coli have been reported.…”

“…A CBD was prepared using a dual UV lamp (85 cm in length) with both UV-A (315-400 nm) and UV-C (100-280 nm; ECOSET Co., Ltd., Ansan, Korea) connected to an electronic controller of 40 W/m 2 , which can be adjusted to emit focused and narrow light. 6 The dual UV lamp was coated on half of the surface by length. The uncoated side of the UV lamp was used.…”

“…3,4 Under ultraviolet (UV) irradiation, these particles mediate oxidative stress in microorganisms. 5,6 Although ZnO is a Zn-based compound generally recognized as safe by the US Food and Drug Administration, 7,8 the safety of ZnO nanoparticles should be confirmed. Exposure risks to the environment and human health also need to be investigated and minimized.…”

“…ZnO nanoparticles are attractive potential broad-spectrum nanoantibiotics. ZnO nanoparticles and their nanoparticles adopted by other metal/metal oxides and other polymers have antimicrobial activity against Escherichia coli, 6,[8][9][10][11] Staphylococcus aureus, [8][9][10] Klebsiella pneumoniae, 11 M13 bacteriophages, 6 and skin-specific pathogens 12 with/without UV irradiation. They also have antimicrobial activity against methicillin-resistant S. aureus based on modification of reactive oxygen species (ROS)-mediated pyridine synthesis and multiple metabolic pathways.…”