Dynamic mechanical stimulations induce anisotropy and improve the tensile properties of engineered tissues produced without exogenous scaffolding
Dynamic mechanical stimulations induce anisotropy and improve the tensile properties of engineered tissues produced without exogenous scaffolding
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DOI：
10.1016/j.actbio.2011.05.034
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发表时间：
2011-09-01
影响因子：
9.7
通讯作者：
Germain, Lucie
中科院分区：
文献类型：
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作者：
Gauvin, Robert;Parenteau-Bareil, Remi;Germain, Lucie
机械强度和细胞外基质（ECM）的产生是设计用于修复和替换经受应力和应变的结缔组织的工程组织的基本特征。在这项研究中，动态机械刺激（DMS）进行了研究，作为一种方法，以提高工程组织的机械性能，而不使用外源性支架，称为自组装方法。该方法完全基于使用人细胞而没有任何外源性支架，允许生产由细胞和由真皮成纤维细胞体外合成的ECM组分组成的组织片。设计了一个生物反应器腔室，以向工程化组织施加循环应变，以确定动态培养是否对其机械性能和ECM组织产生影响。将成纤维细胞在抗坏血酸存在下培养35天以促进ECM产生并允许形成组织片。该片材在定制的锚定系统上生长，允许在生物反应器中容易地操作和固定组织。35天后，将组织在静态培养（SC）中保持3天，或使其经受10%应变的静态机械刺激，或在1Hz下具有10%单轴循环应变的占空比的动态DMS。ECM的特征在于组织学，免疫荧光标记和蛋白质印迹。静态和动态的机械刺激诱导对齐的评估细胞骨架蛋白和ECM成分平行于施加的应变的轴，并增加ECM含量的组织相比，SC。拉伸力学性能的测量结果表明，机械刺激显着增加的极限拉伸强度和拉伸模量的工程组织相比，非刺激的控制。此外，我们表明，循环应变显着增加这些参数相比，静态加载刺激和机械刺激有助于建立自组装组织片的结构和机械性能的各向异性。(C)2011 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Mechanical strength and the production of extracellular matrix (ECM) are essential characteristics for engineered tissues designed to repair and replace connective tissues that are subject to stress and strain. In this study, dynamic mechanical stimulation (DMS) was investigated as a method to improve the mechanical properties of engineered tissues produced without the use of an exogenous scaffold, referred to as the self-assembly approach. This method, based exclusively on the use of human cells without any exogenous scaffolding, allows for the production of a tissue sheet comprised of cells and ECM components synthesized by dermal fibroblasts in vitro. A bioreactor chamber was designed to apply cyclic strain to engineered tissues in order to determine if dynamic culture had an impact on their mechanical properties and ECM organization. Fibroblasts were cultured in the presence of ascorbic acid for 35 days to promote ECM production and allow the formation of a tissue sheet. This sheet was grown on a custom-built anchoring system allowing for easy manipulation and fixation of the tissue in the bioreactor. Following the 35 day period, tissues were maintained for 3 days in static culture (SC), or subjected either to a static mechanical stimulation of 10% strain, or a dynamic DMS with a duty cycle of 10% uniaxial cyclic strain at 1 Hz. ECM was characterized by histology, immunofluorescence labeling and Western blotting. Both static and dynamic mechanical stimulation induced the alignment of assessed cytoskeletal proteins and ECM components parallel to the axis of applied strain and increased the ECM content of the tissues compared to SC. Measurement of the tensile mechanical properties revealed that mechanical stimulation significantly increases both the ultimate tensile strength and tensile modulus of the engineered tissues when compared to the non-stimulated control. Moreover, we demonstrated that cyclic strain significantly increases these parameters when compared to a static-loading stimulation and that mechanical stimulation contributes to the establishment of anisotropy in the structural and mechanical properties of self-assembled tissue sheets. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.