Nanostructure in Cell Adhesive Forces

CBET-0827719A。整合素介导的细胞与细胞外基质的黏附调节许多组织的组织、维持和修复，黏附相互作用的异常通常与病理状态有关。此外，细胞与合成材料的粘附性相互作用支配着宿主对生物医学设备的反应、组织工程结构的生物集成以及生物技术细胞培养载体的开发。黏附过程包括整合素受体与其胞外配体的结合，整合素的聚集，以及包含细胞骨架和信号分子的离散超分子结构的组装。这些焦点黏附复合体作为细胞和细胞外环境之间的结构纽带和信号转导元件发挥作用。虽然在破译调节黏附的生化途径方面已经取得了重大进展，但细胞与其环境之间的机械相互作用仍然知之甚少。本项目的目的是分析纳米尺度的焦点黏附几何结构(簇数、大小、间距)对细胞黏附力和焦点黏附信号的影响。根据“接触分裂”原理，假设焦点粘附力的几何结构对粘附力有调节作用。“触点分裂”机制解释了多少个小触点可以产生比一个相同接触面积的触点更高的粘附力。粘附性界面的结构将使用各种构型的簇状纳米颗粒粘附岛和多价配体来调节，以改变整合素聚集和焦点粘附区和间距。将使用生化和免疫染色技术对成纤维细胞中的整合素结合和局部黏附组装和信号进行量化，并将使用我们的流体动力旋转圆盘法分析黏附强度。这项拟议的研究将整合强大的定量分析、纳米颗粒方法和独特的细胞生物试剂，以精确操纵焦点复合体的组织和生物分子结构，以便分析这些粘附性复合体如何产生粘附力。这些研究将提供对纳米尺度组织和结构对粘附力的产生和调节的贡献的严格、综合的分析。这些研究将对细胞和其细胞外基质之间的机械相互作用的调节产生新的理解。该项目还将导致基于多学科、综合视角的具有独特分析技能的本科生和研究生研究人员的高级培训。来自佐治亚理工学院或我们的亚特兰大大学中心(AUC)计划的一名代表不足的少数族裔学生，将每年被招募到这个项目中工作，以鼓励高等教育和未来的科学和工程职业。AUC是世界上最大的非裔美国人私立高等教育机构联盟，包括克拉克·亚特兰大大学、莫尔豪斯学院和斯佩尔曼学院。

CBET-0827719A. Garcia, Georgia Institute of TechnologyIntegrin-mediated cell adhesion to extracellular matrices regulates the organization, maintenance and repair of numerous tissues, and abnormalities in adhesive interactions are often associated with pathological states. Moreover, cell adhesive interactions with synthetic materials govern host responses to biomedical devices, biological integration of tissue-engineered constructs, and development of biotechnological cell culture supports. The adhesive process comprises integrin receptor binding to their extracellular ligand, integrin clustering, and assembly of discrete supramolecular structures containing cytoskeletal and signaling molecules. These focal adhesion complexes function as structural links and signal transduction elements between the cell and its extracellular environment. While significant progress has been attained in deciphering biochemical pathways regulating adhesion, the mechanical interactions between a cell and its environment remain poorly understood. The objective of this project is to analyze the effects of nanoscale focal adhesion geometrical structure (cluster number, size, spacing) on cell adhesive force and focal adhesion signaling. It is hypothesized that the geometrical organization of the focal adhesion modulates adhesive force based on the "contact splitting" principle. "Contact splitting" mechanics explains how many small contacts can produce a higher adhesion force than one contact with equal contact area. The architecture of the adhesive interface will be modulated using various configurations of clustered nanopatterned adhesive islands and multi-valent ligands to alter integrin clustering and focal adhesion area and spacing. Integrin binding and focal adhesion assembly and signaling in fibroblasts will be quantified using biochemical and immunostaining techniques, and adhesion strength will be analyzed using our hydrodynamic spinning disk assay. The proposed research will integrate robust quantitative assays, nanopatterning approaches, and unique cell biology reagents to precisely manipulate focal complex organization and biomolecular structure in order to analyze how these adhesive complexes generate adhesive forces. These studies will provide rigorous, integrated analyses of the contributions of nanoscale organization and structure to the generation and regulation of adhesive forces. These studies will generate a new understanding of the regulation of mechanical interactions between a cell and its extracellular matrix.This project will also result in the advanced training of undergraduate and graduate researchers with unique analytical skills based on a multi-disciplinary, integrative perspective. One underrepresented minority student, either from Georgia Tech or our Atlanta University Center (AUC) Initiative, will be recruited every year to work in this project to encourage advanced education and future careers in science and engineering. The AUC is the world's largest consortium of African American private institutions of higher education, including Clark Atlanta University, Morehouse College, and Spelman College.