Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology of China (NCNST), Beijing 100190, China.
Department of Medicinal Chemistry, College of Pharmaceutical Sciences of Capital Medical University, Beijing 100069, China.
J Am Chem Soc. 2023 Aug 30;145(34):19086-19097. doi: 10.1021/jacs.3c07048. Epub 2023 Aug 19.
Metal oxide nanozymes have emerged as the most efficient and promising candidates to mimic antioxidant enzymes for treatment of oxidative stress-mediated pathophysiological disorders, but the current effectiveness is unsatisfactory due to insufficient catalytic performance. Here, we report for the first time an intrinsic strain-mediated ultrathin ceria nanoantioxidant. Surface strain in ceria with variable thicknesses and coordinatively unsaturated Ce sites was investigated by theoretical calculation analysis and then was validated by preparing ∼1.2 nm ultrathin nanoplates with ∼3.0% tensile strain in plane/∼10.0% tensile strain out of plane. Compared with nanocubes, surface strain in ultrathin nanoplates could enhance the covalency of the Ce-O bond, leading to increasing superoxide dismutase (SOD)-mimetic activity by ∼2.6-fold (1533 U/mg, in close proximity to that of natural SOD) and total antioxidant activity by ∼2.5-fold. As a proof of concept, intrinsic strain-mediated ultrathin ceria nanoplates could boost antioxidation for improved ischemic stroke treatment , significantly better than edaravone, a commonly used clinical drug.
金属氧化物纳米酶作为模拟抗氧化酶治疗氧化应激介导的病理生理紊乱的最有效和最有前途的候选物已经出现，但由于催化性能不足，目前的效果并不令人满意。在这里，我们首次报道了一种内在应变介导的超薄氧化铈纳米抗氧化剂。通过理论计算分析研究了不同厚度和配位不饱和 Ce 位的氧化铈中的表面应变，然后通过制备厚度约为 1.2nm、平面内约 3.0%拉伸应变/平面外约 10.0%拉伸应变的~1.2nm 超薄纳米板进行了验证。与纳米立方体相比，超薄纳米板中的表面应变可以增强 Ce-O 键的共价性，从而使超氧化物歧化酶（SOD）模拟活性提高约 2.6 倍（1533 U/mg，接近天然 SOD），总抗氧化活性提高约 2.5 倍。作为概念验证，内在应变介导的超薄氧化铈纳米板可以增强抗氧化作用，从而改善缺血性中风治疗效果，明显优于依达拉奉，这是一种常用的临床药物。
