Department of Orthopaedics, University Medical Center Utrecht, Utrecht University, GA Utrecht, 3508, The Netherlands.
Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, MB 5600, The Netherlands.
Sci Rep. 2018 Jan 19;8(1):1245. doi: 10.1038/s41598-018-19502-y.
Reinforcing hydrogels with micro-fibre scaffolds obtained by a Melt-Electrospinning Writing (MEW) process has demonstrated great promise for developing tissue engineered (TE) constructs with mechanical properties compatible to native tissues. However, the mechanical performance and reinforcement mechanism of the micro-fibre reinforced hydrogels is not yet fully understood. In this study, FE models, implementing material properties measured experimentally, were used to explore the reinforcement mechanism of fibre-hydrogel composites. First, a continuum FE model based on idealized scaffold geometry was used to capture reinforcement effects related to the suppression of lateral gel expansion by the scaffold, while a second micro-FE model based on micro-CT images of the real construct geometry during compaction captured the effects of load transfer through the scaffold interconnections. Results demonstrate that the reinforcement mechanism at higher scaffold volume fractions was dominated by the load carrying-ability of the fibre scaffold interconnections, which was much higher than expected based on testing scaffolds alone because the hydrogel provides resistance against buckling of the scaffold. We propose that the theoretical understanding presented in this work will assist the design of more effective composite constructs with potential applications in a wide range of TE conditions.
通过熔融电纺书写（MEW）工艺增强含有微纤维支架的水凝胶在开发具有与天然组织相匹配的机械性能的组织工程（TE）构建体方面显示出巨大的潜力。然而，微纤维增强水凝胶的机械性能和增强机制尚未得到充分理解。在这项研究中，使用实施了实验测量的材料特性的有限元模型来探索纤维-水凝胶复合材料的增强机制。首先，使用基于理想化支架几何形状的连续体有限元模型来捕获与支架抑制凝胶横向膨胀相关的增强效果，而基于实际构建体在压实过程中的微 CT 图像的第二个微有限元模型则捕获了通过支架互连传递负载的效果。结果表明，在较高支架体积分数下的增强机制主要由纤维支架互连的承载能力决定，这比仅根据测试支架预期的要高得多，因为水凝胶提供了对支架屈曲的阻力。我们提出，本工作中提出的理论理解将有助于设计更有效的复合构建体，这些构建体具有在广泛的 TE 条件下应用的潜力。
