Optimal Design of Living Tissue..and Engineering Application

活着的器官和组织经过优化设计，在功能上自我适应，并根据机械应力的变化进行重塑。本研究的目的是对这些现象和机制进行实验研究，用力学模型描述这些现象，并寻求一种工程应用的方法。实验研究表明：1)无论是在静态还是在循环载荷条件下，培养的胶原束都需要一些最佳的应力来保持强度；2)尽管动脉壁的厚度、直径和弹性随着血流和血压的变化而敏感地改变，但管壁剪应力和周向管壁应力始终保持在正常水平；3)骨质量、结构和强度的变化以适应活动的变化。4)机械应激改变巨噬细胞的吞噬活性。此外，还从理论上分析了平滑肌收缩对动脉壁应变和应力分布的影响，并考虑了平滑肌激活对动脉重塑的影响。此外，活体组织的安全系数与人工设计的机器的安全系数进行了比较。这些结果已经并将在几个国际会议和出版的国际科学期刊上发表，并作为书中的一章。这项研究的成员将组织一次关于活组织和细胞的功能适应和重塑的国际研讨会。

Living organs and tissues are optimally designed, and functionally adapt themselves and remodel in response to change in mechanical stress. The purposes of the present study were to experimentally investigate these phenomena and mechanisms, describe the phenomena using mechanical models, and seek an approach for engineering application.The experimental studies have shown that, for example, : 1) some optimal stresses are needed to maintain the strength of collagen fascicles cultured under not only static but also cyclic load conditions, 2) although the thickness, diameter, and elasticity of arterial walls are sensitively changed by the changes in blood flow and blood pressure, wall shear stress and circumferential wall stress are always kept at normal levels, 3) bone mass, structure, and strength change so as to functionally adapt to activity changes. and 4) mechanical stress changes the phagocytotic activity of macrophages. In addition, the effects of smooth muscle contraction on the strain and stress distributions in the arterial wall were theoretically analyzed considering the contribution of smooth muscle activation to arterial remodeling. Moreover, the safety factors of living tissues were compared to those of man-designed machines.These results have been and will be presented at several international conferences and published international scientific journals and as a book chapter. An international symposium on the functional adaptation and remodeling of living tissues and cells will be organized by the members of this study.