The antioxidant properties of Ce-containing bioactive glass nanoparticles explained by Molecular Dynamics simulations

Q1 Materials Science

Biomedical Glasses Pub Date : 2016-04-11 DOI:10.1515/bglass-2016-0003

A. Pedone, Francesco Muniz-Miranda, A. Tilocca, M. Menziani

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引用次数: 17

Abstract

Abstract Molecular dynamics simulations of two glass nanoparticles with composition 25Na2O·25CaO 50SiO2 mol% (Ce-K NP) and 46.1SiO2·24.4Na2O·26.9CaO· 2.6P2O5 mol.% (Ce-BG NP) doped with 3.6 mol% of CeO2 have been carried out in order to explain the enhanced antioxidant properties of the former glass with respect to the latter. The present models show that the different catalase mimetic activity of the two NPs is related to the Ce3+/Ce4+ ratio exposed at their surface. In fact, this ratio is about 3.5 and 13 in the bulk and at the surface of the Ce-BG NP, and 1.0 and 2.1 in the bulk and at the surface of the Ce-K NPs, respectively. Since both oxidation states are necessary for the catalysis of the dismutation reaction of hydrogen peroxides, NPs with a very high Ce3+/Ce4+ ratio possess poorer antioxidant properties. Moreover, our simulations reveal that the already low silicate connectivity found in the bulk glasses examined here is further reduced on the nanoparticle surface, whereas the Na+/Ca2+ ratio rapidly increases. Sodium, calcium and cerium sites in proximity of the surface are found to be under-coordinated, prone to quickly react with water present in physiological environments, thus accelerating the glass biodegradation

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分子动力学模拟解释了含铈生物活性玻璃纳米颗粒的抗氧化性能

摘要:本文对两种由25Na2O·25CaO·50SiO2 mol% (Ce-K NP)和掺杂3.6 mol% CeO2的46.1SiO2·24.4Na2O·26.9CaO·2.6P2O5 mol.% (Ce-BG NP)组成的纳米玻璃进行了分子动力学模拟，以解释前者相对于后者的抗氧化性能增强。该模型表明，两种NPs的模拟过氧化氢酶活性的不同与其表面暴露的Ce3+/Ce4+比值有关。事实上，Ce-BG NP的体积和表面的比值分别约为3.5和13,Ce-K NP的体积和表面的比值分别约为1.0和2.1。由于这两种氧化态都是催化过氧化氢分解反应所必需的，所以Ce3+/Ce4+比例很高的NPs具有较差的抗氧化性能。此外，我们的模拟显示，在这里检查的大块玻璃中已经发现的低硅酸盐连通性在纳米颗粒表面进一步降低，而Na+/Ca2+比率迅速增加。发现靠近表面的钠、钙和铈位点不协调，容易与生理环境中的水快速反应，从而加速玻璃的生物降解

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Biomedical Glasses Materials Science-Surfaces, Coatings and Films

自引率

0.00%

发文量

审稿时长

17 weeks

期刊介绍： Biomedical Glasses is an international Open Access-only journal covering the field of glasses for biomedical applications. The scope of the journal covers the science and technology of glasses and glass-based materials intended for applications in medicine and dentistry. It includes: Chemistry, physics, structure, design and characterization of biomedical glasses Surface science and interactions of biomedical glasses with aqueous and biological media Modeling structure and reactivity of biomedical glasses and their interfaces Biocompatibility of biomedical glasses Processing of biomedical glasses to achieve specific forms and functionality Biomedical glass coatings and composites In vitro and in vivo evaluation of biomedical glasses Glasses and glass-ceramics in engineered regeneration of tissues and organs Glass-based devices for medical and dental applications Application of glasses and glass-ceramics in healthcare.