Wakatsuki T, Kolodney M S, Zahalak G I, Elson E L
Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Biophys J. 2000 Nov;79(5):2353-68. doi: 10.1016/S0006-3495(00)76481-2.
Tissue models reconstituted from cells and extracellular matrix (ECM) simulate natural tissues. Cytoskeletal and matrix proteins govern the force exerted by a tissue and its stiffness. Cells regulate cytoskeletal structure and remodel ECM to produce mechanical changes during tissue development and wound healing. Characterization and control of mechanical properties of reconstituted tissues are essential for tissue engineering applications. We have quantitatively characterized mechanical properties of connective tissue models, fibroblast-populated matrices (FPMs), via uniaxial stretch measurements. FPMs resemble natural tissues in their exponential dependence of stress on strain and linear dependence of stiffness on force at a given strain. Activating cellular contractile forces by calf serum and disrupting F-actin by cytochalasin D yield "active" and "passive" components, which respectively emphasize cellular and matrix mechanical contributions. The strain-dependent stress and elastic modulus of the active component were independent of cell density above a threshold density. The same quantities for the passive component increased with cell number due to compression and reorganization of the matrix by the cells.
由细胞和细胞外基质（ECM）重构而成的组织模型可模拟天然组织。细胞骨架蛋白和基质蛋白决定了组织施加的力及其硬度。在组织发育和伤口愈合过程中，细胞调节细胞骨架结构并重塑细胞外基质以产生力学变化。对重构组织力学性能的表征和控制对于组织工程应用至关重要。我们通过单轴拉伸测量对结缔组织模型——成纤维细胞填充基质（FPMs）的力学性能进行了定量表征。FPMs在应力对应变的指数依赖性以及在给定应变下硬度对力的线性依赖性方面类似于天然组织。通过小牛血清激活细胞收缩力以及用细胞松弛素D破坏F - 肌动蛋白可产生“主动”和“被动”成分，它们分别强调了细胞和基质的力学贡献。活性成分的应变依赖性应力和弹性模量在高于阈值密度时与细胞密度无关。由于细胞对基质的压缩和重组，被动成分的相同量随细胞数量增加。
