DIRECT OBSERVATION OF INTERFACIAL PROCESSES SFM II

直接观察界面过程 SFM II

• 批准号: 2221554
• 负责人: VLADIMIR HLADY
• 金额: $ 16.81万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-04-01 至 1996-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2221554
• 关键词: atomic force microscopy; biomaterial interface interaction; biomaterials; biomedical equipment development; blood proteins; cell adhesion; elasticity; immunoelectron microscopy; intermolecular interaction; ligands; platelet activation; platelets; polymers; protein metabolism; surface property; water

When artificial surfaces are exposed to blood, a single or relatively few molecular signals from non-specific attachment of protein molecules to the surface can cause a fast and precipitous response, such as in the surface activation of the coagulation and complement systems. Blood proteins reach surfaces before the cellular blood components; cellular blood components collide with the surface already covered with a (multi)layer of proteins. This hierarchy of events causes the effects of nonspecific interactions between proteins and the surface to be propagated to a higher, cellular level by mediating the specific attachment of cells to the protein layer. The reason for this is that the attachment of cells to surfaces is controlled by the spatial pattern of proteins which expose their specific amino acid sequence for specific cell membrane receptors. This is equally true for the attachment of platelets to the surfaces of subendothelial matrix and to artificial materials. Direct observation of proteins binding to surfaces by scanning force microscopy (SFM) is now possible. It is also possible to deliberately manipulate surface-bound proteins in ordered arrays using the same scanning probe technique. Our preliminary experiments indicate that the attachment and spreading of platelets can be directly observed in situ with high resolution (10 nm). In this competing continuation application we propose to continue development of SFM as an in situ, high resolution research tool for direct observation of cell interactions with protein-coated biomaterials and model surfaces. In particular, we propose to apply the scanning force microscopy technique to the following studies: 1. The in situ mechanism of platelet adhesion and spreading onto patterned, protein-coated surfaces and onto the surfaces of microphase-separated biomaterials. 2. Characterization of microphase-separated biomaterial surfaces in aqueous environment using SFM adhesion and elasticity maps. 3. Characterization of the homogeneity of biomaterial coatings on the submicron scale using SFM probes with specific ligands attached.

当人造表面暴露于血液时，单个或相对较少 来自蛋白质分子非特异性附着的分子信号 表面会引起快速而急剧的响应，例如 凝结和补体系统的表面激活。 血 蛋白质在细胞血成分之前到达表面；细胞 血液成分与已经覆盖的表面相撞 （多）蛋白质层。 事件的层次结构导致 蛋白质与表面之间的非特异性相互作用 通过介导特异性来传播到较高的细胞水平 细胞附着在蛋白质层上。 原因是 细胞向表面的附着由空间模式控制 蛋白质暴露其特异性氨基酸序列的蛋白质 细胞膜受体。 这同样适用于 血小板到下皮基质的表面和人造 材料。 通过扫描力直接观察蛋白质与表面结合的蛋白质 现在可以显微镜（SFM）。 也可以故意 使用相同的阵列操纵表面结合的蛋白 扫描探针技术。 我们的初步实验表明 可以直接观察到血小板的附着和扩散 具有高分辨率（10 nm）。 在此竞争连续申请中 我们建议继续开发SFM作为原位，高分辨率 直接观察细胞相互作用的研究工具 蛋白质涂层的生物材料和模型表面。 特别是，我们建议应用扫描力显微镜 以下研究的技术： 1。血小板粘附的原位机理并扩散到 图案化的，蛋白质涂层的表面并在 显微合物分离的生物材料。 2。在显微合体分离的生物材料表面的表征 使用SFM粘附和弹性图的水性环境。 3。生物材料涂层的均匀性的表征 使用SFM探针和附有特定配体的SFM探针量表。