Engineered nano-ZnO: nano-ZnO: Doping regulates dissolution and reactive oxygen species levels eliciting biocompatibility

Nano-ZnO being a pre-dominant constituent in every-day utility products encourages to strive for safety. This study was aimed to fill the knowledge gap concerning on mechanism of nano-ZnO toxicity and develop strategies to curb. Synthesized pristine ZnO nanocrystals (NCs) and doping of Fe and Mn in nano-ZnO was characterized for cytotoxicity, reactive oxygen species (ROS) and biotic dissolution traits in Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coll.) bacterial cells. Zinc ions (Zn2+) dissolution and ROS production found responsible in stating toxicological effects of nano-ZnO in E. coll. cells. Over Mn (1.09*10(22)), doping of metal (Fe) atom (1.1*1022) in ZnO lattice introduces kinetic constraints for the release of Zn2+ ions recovered in bacterial pellet which lowers dissolution rate leading low ROS and lipid peroxidation (LPO), delivers high minimum inhibitory concentration (MIC) in both the bacterial cells. Fe doped ZnO NCs also demonstrate effective protective potential in oxidative challenged bacterial cells, with least effect on growth rate, percentage cell viability, membrane damage and ROS production. Further, hemo-compatible response biocompatibility assessed in human red blood cells shows negligible release of hemoglobin (Hb < 12%). (C) 2019 Elsevier Ltd. All rights reserved.