Single-cell mechanobiology: microengineered tools to study cell-matrix remodelling

细胞在重建周围环境中起着积极的作用，这些重塑过程是伤口愈合和疾病进展的关键因素。生物分子基质的异常重塑活性与45%的死亡率有关，但对单个细胞之间的相互作用在驱动组织范围的重塑过程中所知甚少。例如，胶原基质中的细胞会迅速收缩周围组织，使材料变硬。细胞主动响应机械信号，如施加的力和基质刚度，以启动重塑活动。然而，胶原蛋白是一种机械复杂的材料，表现出应变硬化行为，并介导细胞对施加力的反应。理解和描述多种细胞在这种反馈回路中的相互作用将为重塑相关疾病提供新的见解。更直接的是，这些知识可以用于开发新型的刺激反应细胞材料，用于先进的组织工程应用。***为了在单个细胞水平上研究三维环境中力学、细胞和周围基质之间的相互作用，本研究提出了用于单细胞力学生物学研究的新型微工程策略。一个由2名博士和2名硕士研究生组成的团队，在5名本科生的协助下，将开发这些方法，以(i)制造单细胞定位分辨率的三维组织；（ii）能够测量变形矩阵内的局部力和局部矩阵刚度。虽然广泛适用于几个问题，但我们将利用这些技术开发收缩组织的单细胞分辨率模型，该模型可用于设计能够因收缩活动而经历程序化形状变化的智能材料。这些“变形组织”提供了一个平台，可以同时评估我们对收缩力学的理解，同时为组织工程和制造挑战制定策略。***本研究项目为单细胞机械生物学研究开发工具，因此对机械导向疾病的研究至关重要，例如与衰老相关的疾病，其中单细胞可以产生长期影响。这些工程技术可能最终为这些疾病提供新的治疗策略，因此对加拿大来说相当重要，因为目前的医疗保健成本和我们的人口老龄化。更直接的是，这项研究为学员提供了一个令人兴奋的项目，让他们获得与研究和工业领域相关的各种技术的广泛跨学科专业知识，使他们能够通过生物技术或生物工程职业道路为加拿大社会做出贡献。**

Cells play an active role in restructuring their surrounding environment, and these remodeling processes are critical factors in wound healing and disease progression. Abnormal remodeling activity of the biomolecular matrix is associated with 45% of all mortalities, but little is known about the interaction between individual cells in driving a tissue-wide remodeling process. For example, cells within a collagen matrix will rapidly contract the surrounding tissue, stiffening the material. Cells actively respond to mechanical signals such as applied forces and matrix stiffness to initiate remodeling activity. However, collagen is a mechanically complex material, displaying strain-stiffening behaviour, and mediating cellular response to applied forces. Understanding and characterizing how multiple cells interact in this feedback loop will provide new insight into remodeling-related diseases. More immediately, this knowledge may be used to develop new classes of stimuli-responsive cell-based materials, for advanced tissue engineering applications.***To study the interaction between mechanics, cells, and the surrounding matrix in three-dimensional environments at the level of individual cells, this research proposes to develop novel microengineered strategies for single-cell studies of mechanobiology. A team of 2 doctoral and 2 masters candidates, assisted by 5 undergraduate summer students will develop these approaches, to (i) fabricate three-dimensional tissues with single-cell positioning resolution; and (ii) enable the measurement of local forces and local matrix stiffness within the deforming matrices. Though broadly applicable to several problems, we will then leverage these technologies to develop single-cell resolution models of contracting tissues, which can be used to engineer smart materials capable of undergoing programmed shape changes as a result of contractile activity. These `transformer tissues' provide a platform to simultaneously assess our understanding of contractile mechanics, while developing strategies for tissue engineering and manufacturing challenges.***This research program develops tools for studies of single-cell mechanobiology, and is hence of critical importance to the study of mechanically-oriented diseases, such as those associated with aging, in which a single cell can have long-range repercussions. These engineering technologies may ultimately enable novel therapeutic strategies for these conditions, and is hence of considerable importance to Canada, given current healthcare costs and our aging population. More immediately, this research provides an exciting program for trainees to gain broad interdisciplinary expertise in various techniques that are relevant in both research and industrial areas, enabling contributions to Canadian society through biotechnology or bioengineering career paths. **