2012-01-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/642971摘要：物理性的刺激是維持正常細胞與組織結構與功能的重要調節因子。當細胞遭受到這些刺激的調節時，細胞會借由改變其微環境與外來作用力達成新的平衡，細胞與其微環境因此是在一個動態的平衡狀態下。許多組織工程的方法皆希望利用重建這個微環境以促使體外組織的生長。在此微環境下，化學、機械力、結構以及表面地形皆可調節細胞型態並造成細胞內結構的重組與異質性。此外，細胞型態的調控也足以造成幹細胞的分化或是細胞表現型的改變。有趣的是，很少有學者針對細胞型態與作用力的交互影響作深入且系統性的研究。細胞在組織內生長在不同的基質上。而在不同的基質上細胞會表現出不同的表現型。在近年很多的研究中都指出，透過調控細胞的幾何型態，能 夠影響細胞骨架的方向性、結構，以及細胞內的張力，甚至於細胞表現型的改變。另外，因為細胞骨架是支撐細胞形狀的主要結構，透 過拉伸應變影響細胞骨架，可以改變細胞內的功能，包含細胞分裂以及蛋白質表現。綜合這些發現，我們提出的假說是不同表現型或細胞型態會造成細胞骨架結構與功能的改變，因而外加作用力會造成不同的訊號傳遞以及細胞功能的影響。此計畫及利用微製程及生物反應器的科技來探討這些關係，並研究幹細胞及分化細胞之不同結構對作用力的不同反應。生物反應器及具有微型態的彈性薄膜將用來培養細胞並施加各式作用力(張力、壓力及剪力)，並觀察不同型態下的細胞骨架結構以及與細胞內訊號傳遞的相互位置，此外也將研究組織細胞以及幹細胞之不同的表現行對形態及作用力交互作用的反應。本計畫提出機械性刺激對細胞生理及分化影響的新觀點，研究結果將可增加對基礎細胞生物以及幹細胞分化機制的了解，並可由此改進現今促使幹細胞分化的方法，以應用於組織工程和再生醫學。<br> Abstract: Physical forces are major stimulations to cell and tissue, and are crucial in maintaining normal cell and tissue structure and function. In addition, cells modify themselves as well as their microenvironment to create a new balance in response to the physical forces. The cell/extracellular matrix structure therefore is in a dynamic equilibrium with the physical environment. Major tissue engineering efforts have been focusing on recapitulating this mechano-chemical environment in order to promote in vitro tissue growth. One aspect of the cellular mechanical milieu is cell geometry/morphology. Topographical, chemical, and mechanical cues can all result in different cell geometry and thus intracellular reorganization and heterogeneity. However, few studies have examined the effects of cell geometry on cell mechanical responses. The current CDG application proposes to investigate the geometric control of cell mechanotransduction and resulting phenotypic expressions using microfabrication and conventional mechanical technologies. As cells in situ reside in a variety of matrices, they exhibit a number of phenotypic morphologies. Changes to cell morphology/shape have been widely documented to have great consequences in phenotypic expressions in various cell types. Geometric cues have been demonstrated to modulate cytoskeleton structure and intracellular tension. As the support of cellular structures, perturbations to the cytoskeleton via deformational load can change global cellular functions, including proliferation and phenotype. Our hypothesis is therefore that the differential cytoskeleton organization from phenotypic and geometric cues will result in differential cell signaling and function to mechanical loads. We propose to establish bioreactors for applying several modes of mechanical loading (tension, compression, and shear). Mesenchymal stem cell (MSC) morphology will be controlled via microfabricated elastic substrates. Real-time monitoring of cell signaling as well as the resulting cytoskeleton and other intracellular structural changes (nuclear shape, myosin distribution) will be quantified and correlated with the cell signaling responses. Furthermore, phenotypic expression of MSC and differentiated cells in response to the geometric and mechanical cues will be investigated to examine the interaction amongst phenotype, geometry and intracellular structure. The current project proposes an original perspective on the mechano-regulation of MSC physiology and differentiation based on changes in intracellular structure and tension. Findings from this project would greatly benefit fundamental understandings in cell mechanobiology as well as optimization of tissue engineering parameters.力學生物細胞力學生物反應器間葉幹細胞mechanobiologycell mechanicsbioreactorsmesenchymal stem cell