Tissue Engineering and Biomaterials Division, National Institute of Genetic Engineering and Biotechnology, Tehran 14965/161, Iran.
Tissue Engineering and Biomaterials Division, National Institute of Genetic Engineering and Biotechnology, Tehran 14965/161, Iran; School of Mechanical Engineering, Iran University of Science and Technology, Tehran 16844, Iran.
Mater Sci Eng C Mater Biol Appl. 2014 May 1;38:299-305. doi: 10.1016/j.msec.2014.02.015. Epub 2014 Feb 15.
Owing to excellent thermal and mechanical properties, graphene-based nanomaterials have recently attracted intensive attention for a wide range of applications, including biosensors, bioseparation, drug release vehicle, and tissue engineering. In this study, the effects of graphene oxide nanosheet (GONS) content on the linear (tensile strength and strain) and nonlinear (hyperelastic coefficients) mechanical properties of poly(acrylic acid) (PAA)/gelatin (Gel) hydrogels are evaluated. The GONS with different content (0.1, 0.3, and 0.5 wt.%) is added into the prepared PAA/Gel hydrogels and composite hydrogels are subjected to a series of tensile and stress relaxation tests. Hyperelastic strain energy density functions (SEDFs) are calibrated using uniaxial experimental data. The potential ability of different hyperelastic constitutive equations (Neo-Hookean, Yeoh, and Mooney-Rivlin) to define the nonlinear mechanical behavior of hydrogels is verified by finite element (FE) simulations. The results show that the tensile strength (71%) and elongation at break (26%) of composite hydrogels are significantly increased by the addition of GONS (0.3 wt.%). The experimental data is well fitted with those predicted by the FE models. The Yeoh material model accurately defines the nonlinear behavior of hydrogels which can be used for further biomechanical simulations of hydrogels. This finding might have implications not only for the improvement of the mechanical properties of composite hydrogels but also for the fabrication of polymeric substrate materials suitable for tissue engineering applications.
由于具有优异的热学和力学性能，基于石墨烯的纳米材料在生物传感器、生物分离、药物释放载体和组织工程等广泛领域受到了广泛关注。在这项研究中，评估了氧化石墨烯纳米片（GONS）含量对聚（丙烯酸）（PAA）/明胶（Gel）水凝胶线性（拉伸强度和应变）和非线性（超弹性系数）力学性能的影响。将具有不同含量（0.1、0.3 和 0.5wt.%）的 GONS 添加到制备的 PAA/Gel 水凝胶中，并对复合水凝胶进行一系列拉伸和应力松弛测试。使用单轴实验数据对超弹性应变能密度函数（SEDF）进行标定。通过有限元（FE）模拟验证了不同超弹性本构方程（Neo-Hookean、Yeoh 和 Mooney-Rivlin）定义水凝胶非线性力学行为的潜在能力。结果表明，添加 GONS（0.3wt.%）可使复合水凝胶的拉伸强度（71%）和断裂伸长率（26%）显著提高。实验数据与 FE 模型预测的数据吻合较好。Yeoh 材料模型准确地定义了水凝胶的非线性行为，可用于水凝胶的进一步生物力学模拟。这一发现不仅对改善复合水凝胶的力学性能具有重要意义，而且对适用于组织工程应用的聚合物基底材料的制造也具有重要意义。
