Core A: Material Science Core

材料科学核心的基本目标是提供明确定义和专门设计的纳米颗粒（NPs），使三个研究项目的目标得以实现。尽管用于任何生物学或毒理学研究的材料制备并不一定是一项简单的任务，但确保用于生物学研究的工程NPs的物理化学性质和结构安排在实际使用时得到很好的确定是一项重大挑战。人们越来越认识到，单个NPs可以通过分析方法改变，可以在不同的环境中改变结构或化学状态，并可能作为时间的函数而变化。此外，粒子和粒子集合的性质受到聚集、杂质的存在和故意性质的影响

The essential objective of the Materials Science Core is to provide well defined and specifically designed nanoparticles (NPs) that allow the objectives of the three research projects to be addressed. Although materials preparafion for any biological or toxicological study is not necessarily a simple task, the challenges of assuring that the physicochemical properties and structural arrangement of engineered NPs used for biological studies are well established at the fime of actual use are significant. It is increasingly recognized that individual NPs can be altered by the method of analysis, can change structure or chemical state in different environments, and may change as a function of time. In addition, properties of particles and collections of particles are infiuenced by aggregation, the presence of impurities and the nature of deliberate or adventitious coatings. Therefore, in addition to preparing NPs of the desired size, composition and structure, and surface chemistry, it is essential to confirm the nature of the particles at the time of use and to have an understanding of how the particle properties and particle distributions vary with time in the environments of interest. Three different oxide NPs, cerium oxide (ceria), iron oxide, and silica have been identified as the 'primary' particles to be examined in the biological studies. Members ofthe Materials Science research team have experience with the synthesis and characterization of NPforms of these three materials. Our experience with the synthesis and characterization of particles of the desired size (and size distribution), composifion and surface chemistry (or surface functionalization) will be used to achieve the goals of the Core. The team has the background and experience to design and prepare oxide NPs that will enable the PNNL U19 Program to accomplish their three research objectives; Aim 1. Synthesize and characterize the 'primary' nanoparticles desired for biological studies with well defined physicochemical properties. Aim 2. Design and synthesis of nanoparticles optimized for counfing and tracking in biological environments. Aim 3. Understand the impact of different environmental conditions on the fime-dependent properties ofthe primary and coated nanoparticles.