理解皮层组织细胞集体运动行为的物理机制有助于深入了解胚胎发育、癌细胞扩散、伤口愈合等生命现象。复杂的细胞集体动力学行为，如集体迁移、涡旋、结构形成、组织发育等为建立有效的非平衡理论与模型提出新挑战。本项目主要选择上皮层组织细胞体系为研究对象，运用并发展活性物质非平衡动力学模拟与理论方法，如自驱动Voronoi模型、Boltzmann-Ginzburg-Landau理论等，研究皮层组织的细胞集体行为的物理机制。研究细胞的形状极性、手性、记忆效应等单细胞性质对如何影响组织水平的集体行为，如集体迁移，结构形成和相变等；探索皮层组织细胞的创口形貌、细胞迁移速度、细胞外基质的性质等对愈合速率及伤口附近力分布等影响；探索皮层组织细胞的缺陷动力学如何影响细胞凋亡、移除等事件的机理。项目实施将有助于解释和预言生命体系多尺度行为。而细胞组织作为一个典型的非平衡系统，也为研究非平衡统计物理提供一个很好的平台。

Understanding the mechanisms of collective behavior in epithelial tissues sheds light on a better understanding of biological phenomena, such as embryo development, cancer spreading, wound healing and so on. Complicated collective dynamics of cells, for instance, collective migration, vortex motion, pattern formation, tissue developing, and so on, pose new challenges in constructing effective non-equilibrium theories and models. Choosing epithelial tissues as the main research object, we investigate the physical mechanisms of collective behavior in cell populations, by utilizing and developing extensive non-equilibrium models and theories, such as self-propelled Voronoi model (SPV) and Boltzmann-Ginzburg-Landau hydrodynamic theory and so on. In particular, we study how the properties at the single cell level, such as polarity of cell shapes, charity and memory effects, affect the collective behavior at the tissue level, such as collective migration, pattern formation, phase transition and so on. Besides, we try to study the impact of wound morphology, migration speed and properties of extracellular matrix on the wound healing rate and distributions of force in the process of wound healing. Furthermore, we explore the mechanism how the dynamics of topological defects in epithelial tissues dictate cell apoptosis and extrusion. The implementation of the project will help to explain and predict the behavior of living systems at multiple length scales. In contrary, as a typical system far from thermodynamic equilibrium, the cell tissues also provide a good stage for the research of non-equilibrium statistical physics.