title: Selective antibacterial effects of mixed ZnMgO nanoparticles.
abstract: Antibiotic resistance has impelled the research for new agents that can inhibit bacterial growth without showing cytotoxic effects on humans and other species. We describe the synthesis and physicochemical characterization of nanostructured ZnMgO whose antibacterial activity was compared to its pure nano-ZnO and nano-MgO counterparts. Among the three oxides, ZnO nanocrystals-with the length of tetrapod legs about 100 nm and the diameter about 10 nm-were found to be the most effective antibacterial agents since both Gram-positive (B. subtilis) and Gram-negative (E. coli) bacteria were completely eradicated at concentration of 1 mg/mL. MgO nanocubes (the mean cube size ~50 nm) only partially inhibited bacterial growth, whereas ZnMgO nanoparticles (sizes corresponding to pure particles) revealed high specific antibacterial activity to Gram-positive bacteria at this concentration. Transmission electron microscopy analysis showed thatB. subtiliscells were damaged after contact with nano-ZnMgO, causing cell contents to leak out. Our preliminary toxicological study pointed out that nano-ZnO is toxic when applied to human HeLa cells, while nano-MgO and the mixed oxide did not induce any cell damage. Overall, our results suggested that nanostructured ZnMgO, may reconcile efficient antibacterial efficiency while being a safe new therapeutic for bacterial infections.
authors.affiliation: VIM, Institut de la Recherche Agronomique, Jouy en Josas, France.
authors.forename: Jasmina
authors.initials: J
authors.lastname: Vidic
authors.forename: Slavica
authors.initials: S
authors.lastname: Stankic
authors.forename: Francia
authors.initials: F
authors.lastname: Haque
authors.forename: Danica
authors.initials: D
authors.lastname: Ciric
authors.forename: Ronan
authors.initials: R
authors.lastname: Le Goffic
authors.forename: Aurore
authors.initials: A
authors.lastname: Vidy
authors.forename: Jacques
authors.initials: J
authors.lastname: Jupille
authors.forename: Bernard
authors.initials: B
authors.lastname: Delmas
keywords: Antibacterial activity; B. subtilis; E. coli; Metal oxide nanoparticles; Nanoparticle toxicity; ZnMgO