BIOMEMBRANE MECHANICS, SURFACE AFFINITY, AND ADHESION

血细胞的机械变形性不仅是 微循环中流量分布的基本决定因素 还调节细胞聚集、凝集和其他类型的粘合剂 互动。细胞表面“识别”的初始阶段是 由相对表面之间的化学亲和力来定量；这是一种 从细胞中去除异常细胞和物质的重要因素 细胞的循环，细菌和病毒感染，以及停滞和 循环中的白细胞和肿瘤细胞的边际化。的生存能力 当细胞接触受到剪切力的破坏时 循环与粘附力有关，而粘附力又取决于 关于接触的程度和分离的机制。因此， 此应用程序的目标是量化与时间相关的 血细胞的力学性质，血细胞的能量学 细胞-细胞黏附中的变形和化学吸引，以及 粘接触点分离的力学。 具体目的是：(1)将血液的力学性质联系起来 指细胞的结构成分；比较Active和Active 粒细胞的被动变形特性；膜的研究 在细胞活动期间的连续性和脱颗粒过程；测量 吞噬动力与细胞干扰物的作用 结构构件。(2)测量红细胞的机械硬度 粘附性配体结合引起的膜(例如，从 细菌；凝集抗体)；测量形成的潜力 这些配体中的粘附性接触；测量并模拟详细的机制 粘性接触的分离；测量血细胞对 培养的血管内皮细胞。(3)测量动力学和约束性 荧光标记的配体与单个红细胞的关系 黏附强度、时间进程和配体结合量之间的关系； 通过材料的堆积评估粘接强度的增强 当细胞分开时，细胞-细胞接触区。 血细胞变形性和粘附性实验利用独特的 多微操作技术；观察用一种 视频显微镜系统。配体-受体的表面结合及其动力学 用激光显微荧光系统对络合物进行了测量。

The mechanical deformability properties of blood cells are not only essential determinants of flow distribution in the microcirculation but also modulate cell aggregation, agglutination, and other types of adhesive interactions. The initial stage of cell-surface "recognition" is quantitated by the chemical affinity between opposite surfaces; this is an important factor in removal of aberrant cells and material from the circulation, bacterial and viral infection of cells, and arrest and margination of circulating white cells and tumor cells. Viability of cell-cell contacts when exposed to disruption by shear forces in the circulation is related to the strength of adhesion which, in turn, depends on the extent of contact and the mechanics of separation. Hence, the objectives of this application are to quantitate the time-dependent mechanical properties of blood cells, the energetics of blood cell deformation and chemical attraction in cell-cell adhesion, and the mechanics of separation of adhesive contacts. The specific aims are to: (1) Relate the mechanical properties of blood granulocytes to the structural components of the cell; compare active and passive deformation properties of granulocytes; investigate membrane continuity and the degranulation process during cell activity; measure the motive force in phagocytosis and the effect of disruptors of cell structural components. (2) Measure the mechanical stiffening of red cell membranes caused by binding of adhesive ligands (e.g. "adhesins" shed from bacteria; agglutinating antibodies); measure the potential for formation of adhesive contact in these ligands; measure and model the detailed mechanics of separation of adhesive contacts; measure adhesivity of blood cells to cultured vascular endothelium. (3) Measure the kinetics and binding of fluorescently labelled ligands to single red cells; determine the relation between strength of adhesion, time course and magnitude of ligand binding; evaluate augmentation of adhesive strength by accumulation of material into cell-cell contact zones as cells are separated. Blood cell deformability and adhesion experiments utilize unique multi-micromanipulation techniques; the observations are recorded with a video-microscope system. Surface binding and kinetics of ligand-receptor complexes are measured with a laser microfluorometry system.