Gao Xing, Kuśmierczyk Piotr, Shi Zhijun, Liu Changqing, Yang Guang, Sevostianov Igor, Silberschmidt Vadim V
Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Leicestershire LE11 3TU, Loughborough, UK.
Department of Mathematics, Aberystwyth University, Aberystwyth, UK.
J Mech Behav Biomed Mater. 2016 Jun;59:90-98. doi: 10.1016/j.jmbbm.2015.12.021. Epub 2015 Dec 29.
Biological hydrogels, e.g. bacterial cellulose (BC) hydrogel, attracted increasing interest in recent decades since they show a good potential for biomedical engineering as replacements of real tissues thanks mainly to their good biocompatibility and fibrous structure. To select potential candidates for such applications, a comprehensive understanding of their performance under application-relevant conditions is needed. Most hydrogels demonstrate time-dependent behaviour due to the contribution of their liquid phase and reorientation of fibres in a process of their deformation. To quantify such time-dependent behaviour is crucial due to their exposure to complicated loading conditions in body environment. Some hydrogel-based biomaterials with a multi-layered fibrous structure demonstrate a promise as artificial skin and blood vessels. To characterise and model time-dependent behaviour of these multi-layered hydrogels along their through-thickness direction is thereby of vital importance. Hence, a holistic study combining mechanical testing and micro-morphological observations of BC hydrogel with analytical modelling of its relaxation behaviour based on fraction-exponential operators was performed. The results show a good potential to use a fraction-exponential model to describe such behaviour of multi-layered hydrogels, especially at stages of stress decay at low forces and of stress equilibrium at high forces.
生物水凝胶，例如细菌纤维素（BC）水凝胶，在近几十年来引起了越来越多的关注，因为它们在生物医学工程中显示出作为真实组织替代品的良好潜力，这主要归功于它们良好的生物相容性和纤维结构。为了选择此类应用的潜在候选材料，需要全面了解它们在与应用相关条件下的性能。大多数水凝胶由于其液相的贡献以及在变形过程中纤维的重新取向而表现出时间依赖性行为。由于它们在人体环境中会受到复杂的加载条件，因此量化这种时间依赖性行为至关重要。一些具有多层纤维结构的水凝胶基生物材料有望用作人造皮肤和血管。因此，对这些多层水凝胶沿其厚度方向的时间依赖性行为进行表征和建模至关重要。因此，进行了一项全面的研究，将BC水凝胶的力学测试和微观形态观察与其基于分数指数算子的松弛行为分析建模相结合。结果表明，使用分数指数模型来描述多层水凝胶的这种行为具有良好的潜力，特别是在低力下的应力衰减阶段和高力下的应力平衡阶段。
