Cell Anchoring on Nanopatterned Surface Functionality

描述(申请人提供)：细胞附着和细胞间接触的建立是发展先进生物材料的关键问题之一。在外力作用下影响细胞附着、运动和保持的许多参数已经确定。其中包括化学性质和特定功能和因子的呈现，但也包括细胞附着位置(焦点接触点)的分布和细胞几何形状的几何方面，这两者都会引起细胞反应和表型变化。系统地研究焦点接触的纳米分布和大小以及微观细胞形状对细胞黏附稳定性的影响将使用一种通过自组装产生的多功能、无表面形貌的纳米衬底。利用血管内皮细胞作为一种天然的二维细胞类型，对血管移植物的种植具有重要的临床意义，这种纳米技术将揭示内皮细胞如何附着在表面，建立所需的表型，并通过形成明确和稳定的细胞-细胞接触来构建完整的血管衬里。支持这项工作的假设是，为锚定内皮细胞而定义明确的附着位置的纳米级分布导致在生理剪应力下产生稳定的内皮细胞。这一假设将通过以下方式得到验证：(1)使用自组装方法设计和制造尺寸和生物功能可控的光滑纳米颗粒表面；(2)将内皮细胞种植到纳米颗粒上，并分析其在静态和流动条件下的黏附、细胞骨架排列以及细胞间接触的发展和动力学；(3)将(2)的结果与通过微机械加工或模压工艺产生的纳米颗粒表面的观察和测量结果进行对比。这项研究将揭示内皮细胞分化和活性与下表面几何和化学性质之间的系统关系。这一结果将为改进传统聚合物或现代组织工程移植材料的种植过程提供新的设计原则，以建立能够长期预防血管闭塞的内皮细胞衬里。这些原理可能会导致人们长期寻求的设计动脉，这些动脉在其主要结构组件和内层中都是组织工程化的，并在总体上阐明了细胞-生物材料相互作用的机制。

DESCRIPTION (provided by applicant): Cellular attachment and the establishing of cell-cell contacts is one of the key questions in the development of advanced biomaterials. Many parameters that influence cell attachment, motility, and retention under external forces have already been established. Among these are the chemical properties and the presentation of specific functionalities and factors, but also geometric aspects of the distribution of cellular attachment sites (focal contacts) and the cellular geometry, both of which induce cellular responses and changes in phenotype. A systematic investigation of the influence of the nanoscopic distribution and size of focal contacts and of the microscopic cell shape on the stability of cellular adhesion will use a versatile, topography-free nanopatterned substrate produced by self-assembly. Using vascular endothelial cells as a naturally two-dimensional cell type of great clinical significance for the seeding of vascular grafts, this nanopatterning approach will shed light on how endothelial cells attach to surfaces, establish the required phenotype, and build a complete vessel lining by forming well-defined and stable cell-cell contacts. The hypothesis driving this work is that a nanopatterned distribution of well-defined attachment sites for the anchoring of endothelial cells results in a stable endothelium under physiologic shear stress. This hypothesis will be tested by (1) designing and fabricating smooth nanopatterned surfaces of controlled size and biological functionality using self-assembly methods, (2) seeding endothelial cells onto nanopatterns and analyzing their adhesion, cytoskeletal arrangement, and intercellular contact development and dynamics under both static and flow conditions, (3) contrasting the results of (2) with observations and measurements on topographic nanopatterned surfaces created by micromachining or molding processes. This study will reveal systematic relationships between endothelial cell differentiation and activity and the geometric and chemical properties of the underlying surface. The results will provide new design principles to enhance the seeding processes for either traditional polymeric or modern tissue-engineered graft materials to establish an endothelial cell lining that is capable of long-term prevention of vascular occlusion. Such principles could lead to the long-sought designed arteries that are tissue-engineered in their main structural components as well as in the inner lining, and shed light in general on the mechanisms of cell-biomaterial interactions.