Zhang Shaofang, Ruan Haiyan, Xin Qi, Mu Xiaoyu, Wang Hao, Zhang Xiao-Dong
Tianjin Key Laboratory of Brain Science and Neural Engineering, Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin 300072, China.
Department of Physics and Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Sciences, Tianjin University, Tianjin 300350, China.
Nanoscale. 2023 Mar 2;15(9):4408-4419. doi: 10.1039/d2nr05742e.
Artificial enzymes show prospects in biomedical applications due to their stable enzymatic catalytic activity and ease of preparation. CeO nanozymes represent a versatile platform showing multiple enzyme-mimicking activities, although their biocatalytic activities and selectivity are relatively poor for biomedical use. Herein, we developed Mn- and Co-doped CeO nanozymes (M/CeO, M = Mn or Co) atomic engineering to achieve a significant increase in enzyme-like activity. The M/CeO nanozymes exhibited outstanding peroxidase-like activity with a reaction rate about 8-10 times higher than that of CeO. Importantly, the Co/CeO nanozyme preferred for catalase-like activity with a 4-6-fold higher catalytic rate than CeO, while the Mn/CeO nanozyme had a predilection for improving the superoxide dismutase-like capacity. This indicated the selective modulation of enzyme-mimicking activities atomic doping engineering. Cellular level experiments revealed the therapeutic effects of the nanozymes. Mn/CeO and Co/CeO selectively modulated the intracellular redox imbalance in lipopolysaccharide (LPS)- or HO-stimulated nerve cells and improved cell survival. This work provides a feasible strategy for the design of catalytically selective artificial enzymes and facilitates the widespread application of CeO nanozymes in redox-related diseases.
人工酶因其稳定的酶催化活性和易于制备的特点，在生物医学应用中展现出前景。氧化铈纳米酶是一个具有多种模拟酶活性的多功能平台，尽管其生物催化活性和选择性在生物医学应用中相对较差。在此，我们通过原子工程开发了锰和钴掺杂的氧化铈纳米酶（M/CeO，M = Mn或Co），以实现类酶活性的显著提高。M/CeO纳米酶表现出出色的过氧化物酶样活性，反应速率比CeO高约8 - 10倍。重要的是，Co/CeO纳米酶更倾向于具有过氧化氢酶样活性，催化速率比CeO高4 - 6倍，而Mn/CeO纳米酶则倾向于提高超氧化物歧化酶样能力。这表明通过原子掺杂工程可以选择性地调节模拟酶活性。细胞水平实验揭示了纳米酶的治疗效果。Mn/CeO和Co/CeO在脂多糖（LPS）或H₂O₂刺激的神经细胞中选择性地调节细胞内氧化还原失衡，并提高细胞存活率。这项工作为设计具有催化选择性的人工酶提供了一种可行策略，并促进了氧化铈纳米酶在氧化还原相关疾病中的广泛应用。
