DIRECT OBSERVATION OF INTERFACIAL PROCESS

直接观察界面过程

基本信息

批准号：
6682868
负责人：
VLADIMIR HLADY
金额：
$ 22.5万
依托单位：
UNIVERSITY OF UTAH
依托单位国家：
美国
项目类别：
财政年份：
1990
资助国家：
美国
起止时间：
1990-04-01 至 2005-04-30
项目状态：
已结题

项目摘要

OBSERVATION OF INTERFACIAL PROCESSES SPM IV A biomaterial surface, when exposed to a protein-containing solution, becomes coated within seconds with proteins. The hierarchy of events: surface yields protein layer yields platelet and cell adhesion forms the basis of the generally accepted causality between the biomaterial surface property and the attempt of the host organism to isolate artificial material. In this revised competing continuation application, we propose to experimentally analyze the first step in this hierarchy by measuring the protein-biomaterial surface adsorption and to relate it to the two-dimensional variation of biomaterial's surface properties, such as surface energy and elasticity. We propose to perform this analysis on a size scale that is on the order of protein size (i.e. a few tens of nanometers), rather than in a macroscopic fashion. Our research ideal is to build a spatio-temporal picture of biomaterials-host interfaces on nanometers length and milliseconds time scales in terms of: - variation of surface properties, - related dynamics of protein- surface interactions, and surface - induced protein conformation, and to identify the critical parameters in these processes. A question that the proposed research will attempt to answer is: how much biomaterial surface heterogeneity is tolerated and at which length scales? Hence, we propose the four years research plan with the following specific research goals: Using the fast adhesion and elasticity mapping technique measure simultaneously the topography and two-dimensional distribution of adhesion "pull-off" forces and elasticity on well-characterized model surfaces, and surface-modified and typical biomaterials on nanometers length scales. Use the adhesion forces measured in three liquids to spatially resolve non-polar and polar components of surface energy. Establish the rate by which the surface property changes upon a biomaterial's exposure from physiological to non-polar solutions. Study the two-dimensional and/or temporal distribution of major plasma proteins (albumin, fibrinogen, IgG and LDL) at model heterogeneous and selected set of biomaterial surfaces in situ using evanescent surface wave (TIRF) and near-field scanning optical (fluorescence) (NSOM) microscopies. Evaluate the combined information about the biomaterial surface-protein-solution interface obtained from the in situ SFM adhesion mapping and the in situ surface fluorescence spectroscopy techniques. Build a dynamic model of events based on the information that includes the two-dimensional map of biomaterial surface properties and the spatial-temporal distribution of individual plasma proteins.

观察界面过程SPM IV A生物材料表面时，当暴露于含蛋白质溶液的溶液时，将在几秒钟内用蛋白质涂覆。事件的层次结构：表面产生蛋白质层产生血小板和细胞粘附构成了生物材料表面特性和宿主生物体试图分离人造物质的尝试之间因果关系的基础。在此修订后的竞争连续应用中，我们建议通过测量蛋白质生物材料表面吸附，并将其与生物材料表面特性的二维变化（例如表面能和弹性）相关联，以实验分析该层次结构的第一步。我们建议以蛋白质大小（即几十纳米）而不是宏观方式进行尺寸尺度进行此分析。我们的研究理想是在纳米长度上建立生物材料宿主接口的时空图片，并根据以下方面的时间尺度构建以下时间的时间尺度， - 表面特性的变化， - 蛋白质表面相互作用的相关动力学以及表面 - 诱导的蛋白质构象，并在这些过程中识别关键参数。拟议的研究将尝试回答的一个问题是：耐受了多少生物材料表面异质性以及在哪个长度尺度上？因此，我们提出了四年的研究计划，具有以下特定的研究目标：使用快速的粘附和弹性映射技术同时测量了粘附力“拔下”力的形状和二维分布，并在特征良好的模型表面上进行弹性，以及在纳米仪上的表面修饰和典型的生物材料量表上的表面修饰和典型的生物材料。使用在三种液体中测量的粘附力来解决表面能的非极性和极性成分。建立在生物材料从生理溶液中暴露于生物材料的情况下变化的速率。研究使用evaneScent Surface波（TIRF）和近场扫描光学（NSOM）（NSOM）显微镜在模型异质和选择的生物材料表面（纤维蛋白，IgG和LDL）的主要等离子体蛋白（白蛋白，纤维蛋白原，IgG和LDL）的二维和/或时间分布。评估有关从原位SFM粘附映射和原位表面荧光光谱技术获得的生物材料表面蛋白质溶液界面的组合信息。基于包括生物材料表面特性的二维图和单个血浆蛋白的时空分布的信息建立动态事件模型。