Lane Brooks A, Harmon Katrina A, Goodwin Richard L, Yost Michael J, Shazly Tarek, Eberth John F
University of South Carolina, Biomedical Engineering Program, Columbia, SC, USA.
University of South Carolina, Biomedical Sciences, Greenville, SC, USA.
Med Eng Phys. 2018 Mar;53:39-48. doi: 10.1016/j.medengphy.2018.01.003. Epub 2018 Feb 1.
Collagen hydrogels have been used ubiquitously as engineering biomaterials with a biphasic network of fibrillar collagen and aqueous-filled voids that contribute to a complex, compressible, and nonlinear mechanical behavior - not well captured within the infinitesimal strain theory. In this study, type-I collagen, processed from a bovine corium, was fabricated into disks at 2, 3, and 4% (w/w) and exposed to 0, 10, 10, and 10 microjoules of ultraviolet light or enzymatic degradation via matrix metalloproteinase-2. Fully hydrated gels were subjected to unconfined, aqueous, compression testing with experimental data modeled within a continuum mechanics framework by employing the uncommon Blatz-Ko material model for porous elastic materials and a nonlinear form of the Poisson's ratio. From the Generalized form, the Special Blatz-Ko, compressible Neo-Hookean, and incompressible Mooney-Rivlin models were derived and the best-fit material parameters reported for each. The average root-mean-squared (RMS) error for the General (RMS = 0.13 ± 0.07) and Special Blatz-Ko (RMS = 0.13 ± 0.07) were lower than the Neo-Hookean (RMS = 0.23 ± 0.10) and Mooney-Rivlin (RMS = 0.18 ± 0.08) models. We conclude that, with a single fitted-parameter, the Special Blatz-Ko sufficiently captured the salient features of collagen hydrogel compression over most examined formulations and treatments.
胶原水凝胶作为工程生物材料已被广泛应用，它具有由纤维状胶原和充满水的空隙组成的双相网络，这种网络导致了复杂、可压缩和非线性的力学行为，而这种行为在小应变理论中无法很好地描述。在本研究中，从牛真皮中提取的I型胶原被制成2%、3%和4%（w/w）的圆盘，并分别暴露于0、10、20和30微焦耳的紫外线下，或通过基质金属蛋白酶-2进行酶降解。将完全水合的凝胶进行无侧限的水下压缩测试，并通过采用用于多孔弹性材料的不常见的布拉茨-科材料模型和泊松比的非线性形式，在连续介质力学框架内对实验数据进行建模。从广义形式中，推导出了特殊布拉茨-科、可压缩新胡克和不可压缩穆尼-里夫林模型，并报告了每个模型的最佳拟合材料参数。广义模型（均方根误差RMS = 0.13±0.07）和特殊布拉茨-科模型（RMS = 0.13±0.07）的平均均方根误差低于新胡克模型（RMS = 0.23±0.10）和穆尼-里夫林模型（RMS = 0.18±0.08）。我们得出结论，对于大多数研究的配方和处理，特殊布拉茨-科模型只需一个拟合参数就能充分捕捉胶原水凝胶压缩的显著特征。
