Polymer-Coated Cerium Oxide Nanoparticles as Oxidoreductase-like Catalysts
Polymer-Coated Cerium Oxide Nanoparticles as Oxidoreductase-like Catalysts
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DOI：
10.1021/acsami.0c08778
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发表时间：
2020-09-16
影响因子：
9.5
通讯作者：
Berret, Jean-Francois
中科院分区：
文献类型：
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作者：
Baldim, Victor;Yadav, Nisha;Berret, Jean-Francois
氧化铈纳米颗粒通过催化有机底物和活性氧物种的分解来模拟氧化还原酶。这种模仿可以在超氧阴离子自由基和过氧化氢中找到，这是氧化应激相关疾病中产生的有害分子。尽管在纳米医学的背景下，纳米颗粒的功能化是强制性的，但聚合物涂层对其酶样催化活性的影响却知之甚少。在这项工作中，通过将7.8 nm氧化铈核与两个聚丙烯酸钠和四个具有不同端基或锚定端基的聚乙二醇接枝共聚物(如膦酸)结合在一起，制备了六个聚合物包覆的氧化铈纳米颗粒。系统地研究了包覆纳米粒子的超氧化物歧化酶、过氧化氢酶、过氧化物酶和类氧化酶的催化活性。结果表明，聚合物涂层不影响超氧化物歧化酶的活性，破坏过氧化氢酶的活性和氧化物酶的活性，但却显著提高了氧化铈纳米粒子的过氧化物酶活性。研究还表明，用聚乙二醇接枝共聚物包覆的粒子比包覆了聚丙烯酸的粒子具有更好的氧化还原酶样酶活性，这一结果证实了将膦酸作为粒子表面锚定基团的好处。
Cerium oxide nanoparticles have been shown to mimic oxidoreductase enzymes by catalyzing the decomposition of organic substrates and reactive oxygen species. This mimicry can be found in superoxide radicals and hydrogen peroxides, which are harmful molecules produced in oxidative stress-associated diseases. Despite the fact that nanoparticle functionalization is mandatory in the context of nanomedicine, the influence of polymer coatings on their enzyme-like catalytic activity is poorly understood. In this work, six polymer-coated cerium oxide nanoparticles are prepared by the association of 7.8 nm cerium oxide cores with two poly(sodium acrylate) and four poly(ethylene glycol) (PEG)-grafted copolymers with different terminal or anchoring end groups, such as phosphonic acids. The superoxide dismutase-, catalase-, peroxidase-, and oxidase-like catalytic activities of the coated nanoparticles were systematically studied. It is shown that the polymer coatings do not affect the superoxide dismutase-like, impair the catalase-like and oxidase-like, and surprisingly improves peroxidase-like catalytic activities of cerium oxide nanoparticles. It is also demonstrated that the particles coated with the PEG-grafted copolymers perform better than the poly(acrylic acid)-coated ones as oxidoreductase-like enzymes, a result that confirms the benefit of having phosphonic acids as anchoring groups at the particle surface.