O akci
The Role of Surface/Interface Phenomena in The Antibacterial Action of Nano- and Microscale Zinc Oxide, Gallium Oxide, and Gallium Hydroxide.
Abstract
Worldwide trend of increasing antibiotic resistance has spun interest in alternative antibacterial agents such as metal oxide particles. Whereas the antibacterial action of many such oxides is well established, the mechanism of this activity is largely unknown. Cytotoxicity could be mediated via such mechanisms as production of reactive oxygen species, release of toxic cations, charged interactions disrupting cell walls and causing osmotic stress. It is proposed that bacteria cannot develop resistance to oxide treatments because antimicrobial activity occurs through multiple mechanisms. Targeted applications of oxide antibacterials are also hindered by a lack of understanding of the role and nature of the local bacterial environment in mediating/hindering antibacterial interactions. In our studies, to address the nature of interactions between oxide surfaces, cellular membranes and bacterial growth media we employ hydrothermally synthesized nano- and microparticles of undoped and Fe-doped ZnO, β-Ga2O3, as well as GaOOH.
Our growth method allows production of particles with tunable morphology and controllable relative abundances of surfaces with desired polarities. The biological assays with Escherichia coli and Staphylococcus aureus are used to examine the antibacterial action and also to run pre- and post-assay comparative studies of the oxide specimens themselves. For the latter we employ a variety of characterization techniques, such as electron microscopy, energy-dispersive X-ray spectroscopy, time and wavelength dependent surface photovoltage, temperature-dependent photoluminescence spectroscopy, etc.
