Monitoring reactive oxygen species (ROS) on the nanoscale - Combination of DNA origami and ceria nanoparticles

监测纳米级活性氧 (ROS) - DNA 折纸和二氧化铈纳米粒子的组合

• 批准号: 450169704
• 负责人: Professor Dr. Ilko Bald
• 金额: --
• 依托单位: Arbeitsgruppe Hybride Nanostrukturen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/450169704?language=en
• 关键词: Monitoring; reactive; oxygen; species; ROS

Ceria (CeO2) nanoparticles have attracted special interest because of their catalytic and free radical scavenging attributes. The ability of cerium to switch between two oxidation states (Ce3+ and Ce4+ ions) facilitates redox reactions at the nanoparticle surface or scavenging of reactive oxygen species (ROS) and producing relatively harmless, less reactive products. Doping lanthanide ions into ceria, e.g. Eu3+ ions, enhances its catalytic properties due to the increment of oxygen vacancies, providing more active sites for an overall increased redox activity. The project is aimed at determining/characterizing the protective potential of lanthanide doped ceria nanoparticles against ROS. Hydroxyl radicals as model ROS and ssDNA attached onto DNA origami templates to form an anchor for the ceria nanoparticles, which are surface-functionalized with complementary ssDNA, are used in the investigations. Eu3+-doped ceria nanoparticles will be synthesized by a non-hydrolytic sol-gel method and particle surface properties, spectroscopic properties and morphology, among other structural characteristics, will be determined. To achieve biocompatibility (and to combat the formation of protein corona for future use in body), the nanoparticles will be functionalized by ssDNA. Hydroxyl radicals will be generated by a Fenton mechanism. Triangular DNA origami templates will be fabricated and structurally characterized by AFM. ssDNA functionalized lanthanide-doped ceria will be placed onto the DNA-origamis via ssDNA linkers. The length of ssDNA strands will be used to modify the distance of the ceria nanoparticles to the DNA origami and subsequently a nm-scale is defined on which the reactivity of the hydroxyl radicals can be monitored. The ROS scavenging property of ceria will be evaluated on the nanoscale to develop a distance activity relationship, thereby determining the extent in which ceria can protect the ssDNA from hydroxyl radical damage. This will be assessed based on the level of damage observed on the ssDNA strands placed at various distances from the ceria nanoparticles, if any. Fluorescence measurements will be performed before and after the production of the ROS material and will be used in the assessment of the activity. AFM images after production of the hydroxyl radicals will be taken to determine the possible 'damage' on the DNA linkers and the DNA origami.

二氧化铈（CeO 2）纳米颗粒由于其催化和自由基清除属性而引起了特别的兴趣。铈在两种氧化态（Ce 3+和Ce 4+离子）之间切换的能力促进了纳米颗粒表面的氧化还原反应或活性氧物质（ROS）的清除，并产生相对无害、反应性较低的产物。将镧系元素离子掺杂到二氧化铈中，例如Eu 3+离子，由于氧空位的增加而增强了其催化性能，为整体增加的氧化还原活性提供了更多的活性位点。该项目旨在确定/表征镧系元素掺杂的二氧化铈纳米颗粒对ROS的保护潜力。羟基自由基作为模型ROS和ssDNA连接到DNA折纸模板上，以形成用于二氧化铈纳米颗粒的锚，其表面功能化与互补的ssDNA，在调查中使用。Eu 3+掺杂的氧化铈纳米颗粒将通过非水解溶胶-凝胶法合成，并确定颗粒表面性质、光谱性质和形态以及其他结构特征。为了实现生物相容性（并对抗将来在体内使用的蛋白质冠的形成），纳米颗粒将被ssDNA功能化。羟基自由基将通过芬顿机理产生。三角形DNA折纸模板将被制造和结构特征的原子力显微镜。ssDNA官能化的镧系元素掺杂的二氧化铈将通过ssDNA接头置于DNA-折纸上。ssDNA链的长度将用于改变二氧化铈纳米颗粒与DNA折纸的距离，随后定义纳米尺度，在该尺度上可以监测羟基自由基的反应性。将在纳米级上评估二氧化铈的ROS清除性质以形成距离活性关系，从而确定二氧化铈可以保护ssDNA免受羟基自由基损伤的程度。这将基于在放置在离二氧化铈纳米颗粒不同距离处的ssDNA链上观察到的损伤水平（如果有的话）来评估。将在ROS材料生产前后进行荧光测量，并用于活性评估。在羟基自由基产生后，将拍摄AFM图像，以确定DNA连接体和DNA折纸上可能的“损伤”。