The chelating gadolinium-complex is routinely used as magnetic resonance imaging (MRI) -contrast enhancer. However, several safety issues have recently been reported by FDA and PRAC. There is an urgent need for the next generation of safer MRI-contrast enhancers, with improved local contrast and targeting capabilities. Cerium oxide nanoparticles (CeNPs) are designed with fractions of up to 50% gadolinium to utilize the superior MRI-contrast properties of gadolinium. CeNPs are well-tolerated in vivo and have redox properties making them suitable for biomedical applications, for example scavenging purposes on the tissue- and cellular level and during tumor treatment to reduce in vivo inflammatory processes. Our near edge X-ray absorption fine structure (NEXAFS) studies show that implementation of gadolinium changes the initial co-existence of oxidation states Ce3+ and Ce4+ of cerium, thereby affecting the scavenging properties of the nanoparticles. Based on ab initio electronic structure calculations, we describe the most prominent spectral features for the respective oxidation states. The as-prepared gadolinium-implemented CeNPs are 3–5 nm in size, have r1-relaxivities between 7–13 mM−1 s−1 and show clear antioxidative properties, all of which means they are promising theranostic agents for use in future biomedical applications.
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机译:螯合-复合物通常用作磁共振成像(MRI)对比增强剂。但是,FDA和PRAC最近报告了一些安全问题。迫切需要下一代安全性更高的MRI对比增强剂,它们具有改进的局部对比度和靶向能力。氧化铈纳米颗粒(CeNPs)的with含量高达50%,可利用of的MRI对比特性。 CeNP在体内具有良好的耐受性,并具有氧化还原特性,使其适合生物医学应用,例如在组织和细胞水平上以及在肿瘤治疗过程中的清除目的,以减少体内炎症过程。我们的近边缘X射线吸收精细结构(NEXAFS)研究表明,implementation的实施改变了铈氧化态Ce 3 + sup>和Ce 4 + sup>的初始共存,从而影响纳米颗粒的清除性能。基于从头算电子结构的计算,我们描述了各个氧化态最突出的光谱特征。 g制备的CeNPs尺寸为3–5 nm,r1松弛度在7–13 mM -1 sup> s -1 sup>之间,并显示出清晰的抗氧化特性,所有这些都意味着它们有望在未来的生物医学应用中使用治疗药物。
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