Combined numerical and experimental biomechanical characterization of soft collagen hydrogel substrate.
Combined numerical and experimental biomechanical characterization of soft collagen hydrogel substrate.
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软胶原水凝胶底物的数值和实验生物力学表征。
DOI：
10.1007/s10856-016-5688-3
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发表时间：
2016-04
期刊：
影响因子：
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通讯作者：
Lacroix D
中科院分区：
文献类型：
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作者：
Castro AP;Laity P;Shariatzadeh M;Wittkowske C;Holland C;Lacroix D
这项工作提出了一个组合的实验-数值框架的生物力学特性的高度水合胶原蛋白水凝胶，即0.20，0.30和0.40%（重量）的胶原蛋白浓度。胶原蛋白是动物和人类细胞外基质中最丰富的蛋白质。其内在的生物相容性使胶原蛋白成为一种有前途的基质，用于将细胞包埋在模仿天然软组织的高度水合环境中。细胞行为受周围基质的机械性质的影响很大，但胶原蛋白水凝胶的生物力学表征迄今为止一直具有挑战性，因为它们呈现非线性孔隙粘弹性性质。结合胶原渗透性的相关文献数据，从流变学实验的刚度结果，多孔弹性有限元（FE）模型开发。文献中的实验侧限压缩试验和类似的有限元应力松弛曲线之间的比较表明，在整个测试中的密切协议。该框架允许确定胶原水凝胶的动态剪切模量在0.20%浓度的0.0097 ± 0.018 kPa和0.40%浓度的0.0601 ± 0.044 kPa之间。这种条件下的泊松比值分别在0.20%的0.495 - 0.485和0.40%的0.480 - 0.470的范围内，表明流变学足够敏感，可以检测胶原蛋白浓度的这些微小变化，因此可以将流变学结果与有限压缩试验联系起来。总之，这种集成的方法允许胶原蛋白水凝胶的准确的组成建模。该框架为相关水凝胶的表征和在更复杂的多尺度模型中使用胶原蛋白参数化奠定了基础。
This work presents a combined experimental–numerical framework for the biomechanical characterization of highly hydrated collagen hydrogels, namely with 0.20, 0.30 and 0.40 % (by weight) of collagen concentration. Collagen is the most abundant protein in the extracellular matrix of animals and humans. Its intrinsic biocompatibility makes collagen a promising substrate for embedding cells within a highly hydrated environment mimicking natural soft tissues. Cell behaviour is greatly influenced by the mechanical properties of the surrounding matrix, but the biomechanical characterization of collagen hydrogels has been challenging up to now, since they present non-linear poro-viscoelastic properties. Combining the stiffness outcomes from rheological experiments with relevant literature data on collagen permeability, poroelastic finite element (FE) models were developed. Comparison between experimental confined compression tests available in the literature and analogous FE stress relaxation curves showed a close agreement throughout the tests. This framework allowed establishing that the dynamic shear modulus of the collagen hydrogels is between 0.0097 ± 0.018 kPa for the 0.20 % concentration and 0.0601 ± 0.044 kPa for the 0.40 % concentration. The Poisson’s ratio values for such conditions lie within the range of 0.495–0.485 for 0.20 % and 0.480–0.470 for 0.40 %, respectively, showing that rheology is sensitive enough to detect these small changes in collagen concentration and thus allowing to link rheology results with the confined compression tests. In conclusion, this integrated approach allows for accurate constitutive modelling of collagen hydrogels. This framework sets the grounds for the characterization of related hydrogels and to the use of this collagen parameterization in more complex multiscale models.