Computational model of cellular adhesion in bulk flows

描述（由申请人提供）：理解、操纵和控制细胞粘附过程对于开发通过循环系统靶向药物递送、在生物反应器中生长自组装组织结构以及使生物传感器用于检测环境细菌等策略至关重要。然而，在我们的知识的细胞-细胞粘附在流体力学剪切流动条件下的关键问题仍然没有得到解决。因此，申请人正在开发基于浸没边界法的计算模型，以模拟细胞-细胞相互作用，其考虑了分子相互作用和细胞膜对整体流动的响应。建议的建设和发展的数值工具将指导和验证的剪切条件下，对免疫反应至关重要的受体介导的白细胞-金黄色葡萄球菌细菌细胞的相互作用的测量。金黄色葡萄球菌菌株是导致感染的原因，这些感染可能导致毁灭性后果，包括脓毒症伴多器官衰竭、心内膜炎、关节炎、脊椎骨髓炎、硬膜外脓肿和眼内炎。我们的计算模型的细胞在剪切流被用来模拟细胞间的碰撞变形细胞。此外，通过将可变形细胞模型与受体-配体结合的概率模型相结合，可以获得白细胞-S的重要生物力学和动力学参数。可以计算Aureus粘附相互作用。描述真实的细胞细节将使我们能够更好地估计模型参数，如细胞间接触面积，接触时间和压缩力和张力作为细胞特性和影响细胞粘附的流体动力学剪切的函数。拟议的研究还将为分析其他受体介导的细胞相互作用提供一个框架，这些相互作用在生物技术和细胞生理学的不同过程中发挥着重要作用，并将显着推进我们对流体物理学，血管生物学和纳米尺度分子相互作用的理解。

DESCRIPTION (provided by applicant): Understanding, manipulating and controlling cellular adhesion processes is crucial to developing strategies among others, to target drug delivery via the circulatory system, grow self-assembling tissue structures in bioreactors, and miniaturize biosensors for the detection of environmental bacteria. Yet, key issues in our knowledge of cell-cell adhesion under hydrodynamic shear flow conditions remain unresolved. Therefore a computational model based on the immersed boundary method is being developed by the applicants to simulate cell-cell interactions that accounts for both the molecular interactions and the response of the cell membrane to the bulk flow. The proposed construction and development of the numerical tools will be guided and validated by measurements of receptor-mediated leukocyte-Staphylococcus Aureus bacterial cell interactions under shear conditions, critical to the immune response. Staphylococcus Aureus bacterial strains are responsible for infections which may lead to devastating consequences including sepsis with multi-organ failure, endocarditis, arthritis, vertebral osteomyelitis, epidural abscess and endophthalmitis. Our computational model of a cell in a shear flow is used to simulate intercellular collisions between deformable cells. Moreover, by integrating the deformable cell model with a probablistic model of receptor-ligand binding, important biomechanical and kinetic parameters for leukocyte-S. Aureus adhesive interactions can be calculated. Incorporating realistic cellular details will enable us to better estimate the model parameters such as intercellular contact area, contact duration and compressive and tensile forces as a function of the cellular properties and hydrodynamic shear that influence cellular adhesion. The proposed studies will also provide a framework for analyzing other receptor-mediated cellular interactions that play a fundamental role n diverse processes in biotechnology and cell physiology, and will significantly advance our understanding at the interface of fluid physics, vascular biology and nano-scale molecular interactions.