title: Morphological impact of zinc oxide particles on the antibacterial activity and human epithelia toxicity.
abstract: ZnO nanoparticles are utilized in an ever growing number of products and can, therefore, be readily encountered in our everyday life. Human beings' outermost tissues consist of different epithelia and are, therefore, the most exposed to materials from the environment. In this paper, Caco-2 and Calu-3 cell lines were used, having been previously broadly applied for in vitro modelling of intestinal and respiratory epithelia, respectively. The toxicity of synthesized micro-, submicro- and nanoparticulate ZnO on these epithelia was measured and compared to the efficacy of the same ZnO particles as antibacterial agents. An approximately four-fold excess in antibacterial activity of ZnO nanoparticles over ZnO granulate was observed. The results of this paper reveal a sharp distinction between toxic nanoparticulate ZnO and safe ZnO particles of larger sizes in intestinal and airway in vitro epithelial models. In contrast, ZnO of larger particle sizes had only modestly lower antibacterial activity, which can be compensated for with higher dosing. These results show that nanoparticulate ZnO requires critical in vivo assessment before application.
authors.affiliation: National Institute of Chemistry, Hajdrihova 19, SI 1000 Ljubljana, Slovenia.
authors.forename: Marjeta
authors.initials: M
authors.lastname: Čepin
authors.affiliation: National Institute of Chemistry, Hajdrihova 19, SI 1000 Ljubljana, Slovenia.
authors.forename: Gorazd
authors.initials: G
authors.lastname: Hribar
authors.affiliation: National Institute of Chemistry, Hajdrihova 19, SI 1000 Ljubljana, Slovenia.
authors.forename: Simon
authors.initials: S
authors.lastname: Caserman
authors.affiliation: National Institute of Chemistry, Hajdrihova 19, SI 1000 Ljubljana, Slovenia.
authors.forename: Zorica Crnjak
authors.initials: ZC
authors.lastname: Orel
mesh_terms: D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000737:chemistry* / Q000494:pharmacology*; D018938:Caco-2 Cells; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D006801:Humans; D053758:Nanoparticles / Q000009:adverse effects / Q000737:chemistry*; D015034:Zinc Oxide / Q000009:adverse effects / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D015034:Zinc Oxide
keywords: Antibacterial activity; Caco-2; Calu-3; E. coli; Epithelium model; Toxicity; ZnO nanoparticles