Biomechanics of Damage, Growth and Remodelling

损伤、生长和重塑的生物力学

• 批准号: RGPIN-2015-06027
• 负责人: Federico, Salvatore
• 金额: $ 2.11万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=650553
• 关键词: Biomechanics; Damage; Growth; Remodelling

Biological tissues constitute the organs of living beings, and are comprised of cells of the same type embedded in a ground material called extracellular matrix. The extracellular matrix can be described as a porous material, reinforced by collagen fibres and saturated by a fluid in which several chemical substances are dissolved. ***The greatest difference between engineering materials and biological tissues is that the latter are living materials that interact with and sense stimuli from the surrounding environment. Because of these interactions, they undergo processes of growth, remodelling and, in unfortunate cases, injury and damage. Growth is defined as the increase (accretion) or decrease (resorption) of mass, remodelling as the rearrangement of the internal structure, and damage as the loss of structural integrity. ***Our research is aimed at developing a unified continuum mechanical model of biological tissues accounting for damage, growth and remodelling, as well as for the interaction among the three phenomena. We seek for an energy-based model, i.e., a model in which virtually all information about the behaviour of the tissue can be included in a single mathematical function, the (Helmholtz) free energy. The derivation of the mathematical expression of the free energy comes from considerations made on the microstructure of the tissue. Specifically, we are interested in the electromechanical interactions among the macromolecules in the matrix, collagen fibre reorientation under external stimuli, which accounts for a good part of the remodelling, and collagen fibre failure, which ultimately determines tissue damage. Emphasis will be placed on the study of blood vessels and articular cartilage, and experiments will be performed to validate the individual components of the unified model.***Such a general approach has never been attempted before and will give us the possibility to obtain information on the complex interaction among these phenomena, which is otherwise virtually impossible to quantify experimentally. Specific experiments will be performed on simple geometries to validate the damage and remodelling aspects of the model, individually.***The long-term objectives of this research are: ***1) To model the molecular mechanisms of damage in soft tissues, and how damage triggers and interacts with growth and remodelling;***2) To design techniques aimed at mechanically, chemically, electrically stimulating the biosynthetic response of the cells in the tissue in order to promote a specific response, as well as tissue-engineered materials capable of replacing irremediably damaged tissue, as is the case for articular cartilage. ***This programme will strongly contribute to the training of graduate students and postdocs in the foundations of Continuum Mechanics and its applications to Soft Tissue Biomechanics, as well as in the experimental techniques necessary for model validation.

生物组织构成生物的器官，由嵌入称为细胞外基质的基质中的相同类型的细胞组成。细胞外基质可以描述为一种多孔材料，由胶原纤维增强，并被溶解有多种化学物质的液体所饱和。 ***工程材料与生物组织最大的区别在于，后者是与周围环境相互作用并感知周围环境刺激的生命材料。由于这些相互作用，它们经历了生长、重塑的过程，在不幸的情况下，还经历了伤害和损害。生长被定义为质量的增加（增加）或减少（吸收），重塑为内部结构的重新排列，损坏为结构完整性的丧失。 ***我们的研究旨在开发一个统一的生物组织连续力学模型，解释损伤、生长和重塑，以及这三种现象之间的相互作用。我们寻求一种基于能量的模型，即几乎所有有关组织行为的信息都可以包含在单个数学函数（亥姆霍兹）自由能中的模型。自由能数学表达式的推导来自于对组织微观结构的考虑。具体来说，我们对基质中大分子之间的机电相互作用、外部刺激下的胶原纤维重新定向（这在重塑中占很大一部分）以及胶原纤维失效（最终决定组织损伤）感兴趣。重点将放在血管和关节软骨的研究上，并将进行实验来验证统一模型的各个组成部分。***这种通用方法以前从未尝试过，将使我们有可能获得信息这些现象之间复杂的相互作用，否则实际上不可能通过实验来量化。将在简单的几何形状上进行具体实验，以分别验证模型的损伤和重塑方面。***本研究的长期目标是：***1) 模拟软组织损伤的分子机制，以及损伤如何触发生长和重塑并与之相互作用；***2) 设计旨在机械、化学、电刺激组织中细胞的生物合成反应以促进特定反应的技术，以及组织工程技术可替代的材料不可挽回地受损的组织，如关节软骨的情况。 ***该计划将极大地促进研究生和博士后在连续介质力学基础及其在软组织生物力学中的应用以及模型验证所需的实验技术方面的培训。