DBT-National Institute of Animal Biotechnology (NIAB), Opposite Journalist Colony, Near Gowlidoddy, Extended Q-City Road, Gachibowli, Hyderabad 500032, Telangana, India; DBT-Regional Centre for Biotechnology (RCB), Faridabad 121001, Haryana, India.
DBT-National Institute of Animal Biotechnology (NIAB), Opposite Journalist Colony, Near Gowlidoddy, Extended Q-City Road, Gachibowli, Hyderabad 500032, Telangana, India; DBT-Regional Centre for Biotechnology (RCB), Faridabad 121001, Haryana, India.
Colloids Surf B Biointerfaces. 2023 Nov;231:113531. doi: 10.1016/j.colsurfb.2023.113531. Epub 2023 Sep 4.
Bacterial infections are considered as one of the major health threats to the global population. The advent of bacterial species with antibiotic resistance has attracted significant efforts to develop novel materials and strategies to effectively avoid the resistance with enhanced antibacterial potential. In this work, we have developed oxidase-mimetic cerium oxide nanoparticles (CeO NPs), which exhibit nanozyme activity at physiological pH in the presence of adenosine triphosphate (ATP). The oxidase-mimetic activity was confirmed to involve superoxide radicals using p-benzoquinone and dihydroethidium. Using indole propionic acid, ethanol, and terephthalic acid, it was confirmed that the oxidase-mimetic activity of CeO NPs with ATP does not involve the formation of hydroxyl radicals. CeO NPs with ATP produced a strong antibacterial activity against Staphylococcus aureus and Escherichia coli within 3 - 6 hrs. The bacterial cell morphology analysis suggested that superoxide radicals generated during the oxidase-mimetic activity of CeO NPs with ATP cause distortion of paired and tetrad arrangement (Staphylococcus aureus), loss of cytoplasmic content, damage, and pore formation in the cell wall (Escherichia coli) that led to the death of bacteria. Further, the live/dead assay also concludes the time-dependent death of bacterial cells with the highest death in the cell population exposed to CeO NPs and ATP. Thus, the antibacterial activity at physiological pH by superoxide radical generating oxidase-mimetic CeO NPs could be further extended to other pathogenic bacterial species.
细菌感染被认为是全球人口的主要健康威胁之一。具有抗生素耐药性的细菌种类的出现引起了人们极大的兴趣，促使人们开发新型材料和策略，以有效避免耐药性并增强抗菌潜力。在这项工作中，我们开发了氧化酶模拟氧化铈纳米粒子（CeO NPs），它在生理 pH 下、在三磷酸腺苷（ATP）存在的条件下表现出纳米酶活性。通过对邻苯醌和二氢乙啶的使用，证实了氧化酶模拟活性涉及超氧自由基。通过吲哚丙酸、乙醇和对苯二甲酸的使用，证实了 CeO NPs 与 ATP 的氧化酶模拟活性不涉及羟基自由基的形成。CeO NPs 与 ATP 在 3-6 小时内对金黄色葡萄球菌和大肠杆菌表现出强烈的抗菌活性。细菌细胞形态分析表明，CeO NPs 与 ATP 的氧化酶模拟活性产生的超氧自由基导致配对和四联体排列的扭曲（金黄色葡萄球菌）、细胞质内容物的损失、细胞壁的损伤和孔形成（大肠杆菌），导致细菌死亡。此外，活/死测定也得出结论，随着暴露于 CeO NPs 和 ATP 的细菌细胞数量的增加，细菌细胞会发生时间依赖性死亡。因此，通过产生超氧自由基的氧化酶模拟 CeO NPs 在生理 pH 下的抗菌活性可能会进一步扩展到其他致病性细菌种类。
