Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
Tissue Eng Part C Methods. 2011 May;17(5):527-36. doi: 10.1089/ten.TEC.2010.0547. Epub 2011 Feb 3.
The present study describes the design and validation of a simple apparatus to apply simultaneous mechanical and fluidic stress to three-dimensional (3D) cell-seeded collagen hydrogels. Constructs were formed in wells in a silicone substrate that could be stretched cyclically, and were also fitted with inlet ports to apply fluid flow. Acid etching was used to retain adhesion of the gels to the walls of the well, and an acellular layer of collagen hydrogel was used to distribute flow evenly. Finite element modeling showed that 5% uniaxial strain applied to the entire silicone substrate resulted in ∼6.5% strain in each of the gel constructs. Permeability testing and flow observation showed that acellular hydrogels were fourfold more permeable than cardiac fibroblast-seeded gels, and that the fluid distributed evenly in the acellular layer before entering the cell-seeded gel. Viability testing and imaging demonstrated that cells remained viable with expected fibroblast morphology for the 120 h duration of the experiments. These results demonstrate that this simple bioreactor can be used to study the effects of mechanical strain and interstitial flow in 3D protein hydrogels. Such 3D tissue models have utility in studying cell and tissue responses to their mechanical environment.
本研究描述了一种简单装置的设计和验证，该装置可对三维（3D）细胞接种胶原水凝胶施加同时的机械和流体应力。构建体在硅酮基质的孔中形成，可进行周期性拉伸，并配有入口端口以施加流体流动。酸蚀用于保留水凝胶与孔壁的粘附，而无细胞胶原水凝胶层用于均匀分配流动。有限元模拟表明，施加于整个硅酮基质的 5%单轴应变导致每个凝胶构建体中的应变约为 6.5%。渗透性测试和流动观察表明，无细胞水凝胶比心脏成纤维细胞接种凝胶的渗透性高四倍，并且在进入细胞接种凝胶之前，流体在无细胞层中均匀分布。活力测试和成像表明，细胞在实验的 120 小时内保持活力，呈现预期的成纤维细胞形态。这些结果表明，这种简单的生物反应器可用于研究 3D 蛋白水凝胶中的机械应变和间质流动的影响。这种 3D 组织模型可用于研究细胞和组织对其机械环境的反应。
