Understanding the mode of action of nano metal oxide to engineer safer nano antibacterials: bio-interactions in lung cells
Paride Mantecca, E. Moschini
Department of Earth and Environmental Sciences, Research Center POLARIS, University of Milano Bicocca
Nanosized Zinc oxide (nZnO) and Copper oxide (nCuO) are employed in many industrial sectors and are among the most produced NMs globally. They are suggested as candidates for the replacement of the highly toxic nano Ag for antibacterial applications. In the frame of sustainable and safe development of nanotechnologies, the knowledge of the biological reactivity of these NMs in function of their physical and chemical properties (e.g. size, shape, crystallinity, oxidative potential) is crucial. The tuning of NP properties may affect the modality of cell-NP interactions and the biological responses elicited. Since the vast surface area, the respiratory system is retained to be the most impacted by NPs, making the study on the NP interactions with lung cells mandatory.
In this work, the human alveolar epithelial cells A549 were exposed to ZnO, CuO and Zn-doped CuO NPs for increasing time and concentrations. Cell viability and oxidative stress biomarkers were comparatively evaluated, while nano-bio-interactions were studied by electron and confocal microscopy. The results were interpreted according to NP size, shape, oxidative potential, extra- and intra-cellular dissolution, and modality of cell uptake.
By comparing these results with the bactericidal activity it will be possible to harmonize the toxic- and the safe-by-design approaches, allowing the synthesis of highly efficient and safer antibacterial NMs.
This work was supported by Fondazione Cariplo (OverNanotox 2013-0987)
