Irastorza Ramiro M, Drouin Bernard, Blangino Eugenia, Mantovani Diego
Instituto de Física de Líquidos y Sistemas Biológicos, CONICET-CCT La Plata, B1900BTE La Plata, Buenos Aires, Argentina ; Instituto de Ingeniería y Agronomía, Universidad Nacional Arturo Jauretche, 1888 Florencio Varela, Buenos Aires, Argentina.
Laboratory for Biomaterials and Bioengineering, Canada Research Chair I, Laval University, Quebec City, QC, Canada G1V 0A6.
ScientificWorldJournal. 2015;2015:859416. doi: 10.1155/2015/859416. Epub 2015 Mar 5.
Small diameter tissue-engineered arteries improve their mechanical and functional properties when they are mechanically stimulated. Applying a suitable stress and/or strain with or without a cycle to the scaffolds and cells during the culturing process resides in our ability to generate a suitable mechanical model. Collagen gel is one of the most used scaffolds in vascular tissue engineering, mainly because it is the principal constituent of the extracellular matrix for vascular cells in human. The mechanical modeling of such a material is not a trivial task, mainly for its viscoelastic nature. Computational and experimental methods for developing a suitable model for collagen gels are of primary importance for the field. In this research, we focused on mechanical properties of collagen gels under unconfined compression. First, mechanical viscoelastic models are discussed and framed in the control system theory. Second, models are fitted using system identification. Several models are evaluated and two nonlinear models are proposed: Mooney-Rivlin inspired and Hammerstein models. The results suggest that Mooney-Rivlin and Hammerstein models succeed in describing the mechanical behavior of collagen gels for cyclic tests on scaffolds (with best fitting parameters 58.3% and 75.8%, resp.). When Akaike criterion is used, the best is the Mooney-Rivlin inspired model.
小直径组织工程动脉在受到机械刺激时，其力学和功能特性会得到改善。在培养过程中，对支架和细胞施加合适的应力和/或应变（有无循环均可）取决于我们生成合适力学模型的能力。胶原凝胶是血管组织工程中最常用的支架之一，主要是因为它是人体血管细胞外基质的主要成分。对这种材料进行力学建模并非易事，主要是由于其粘弹性性质。开发适用于胶原凝胶的模型的计算和实验方法对该领域至关重要。在本研究中，我们聚焦于胶原凝胶在无侧限压缩下的力学性能。首先，在控制系统理论中讨论并构建力学粘弹性模型。其次，使用系统辨识对模型进行拟合。对多个模型进行评估，并提出了两个非线性模型：受穆尼-里夫林启发的模型和哈默斯坦模型。结果表明，穆尼-里夫林模型和哈默斯坦模型成功地描述了胶原凝胶在支架循环测试中的力学行为（最佳拟合参数分别为58.3%和75.8%）。当使用赤池准则时，最佳模型是受穆尼-里夫林启发的模型。
