Beckett Laura E, Lewis Jackson T, Tonge Theresa K, Korley LaShanda T J
University of Delaware, Department of Materials Science and Engineering, 127 The Green, Newark, Delaware 19716, United States.
W. L. Gore & Associates, Inc., 501 Vieves Way, Elkton, Maryland 21921, United States.
ACS Biomater Sci Eng. 2020 Oct 12;6(10):5453-5473. doi: 10.1021/acsbiomaterials.0c00911. Epub 2020 Sep 25.
Reinforcing mechanically weak hydrogels with fibers is a promising route to obtain strong and tough materials for biomedical applications while retaining a favorable cell environment. The resulting hierarchical structure recreates structural elements of natural tissues such as articular cartilage, with fiber diameters ranging from the nano- to microscale. Through control of properties such as the fiber diameter, orientation, and porosity, it is possible to design materials which display the nonlinear, synergistic mechanical behavior observed in natural tissues. In order to fully exploit these advantages, it is necessary to understand the structure-property relationships in fiber-reinforced hydrogels. However, there are currently limited models which capture their complex mechanical properties. The majority of reported fiber-reinforced hydrogels contain fibers obtained by electrospinning, which allows for limited spatial control over the fiber scaffold and limits the scope for systematic mechanical testing studies. Nevertheless, new manufacturing techniques such as melt electrowriting and bioprinting have emerged, which allow for increased control over fiber deposition and the potential for future investigations on the effect of specific structural features on mechanical properties. In this review, we therefore explore the mechanics of fiber-reinforced hydrogels, and the evolution of their design and manufacture from replicating specific features of biological tissues to more complex structures, by taking advantage of design principles from both tough hydrogels and fiber-reinforced composites. By highlighting the overlap between these fields, it is possible to identify the remaining challenges and opportunities for the development of effective biomedical devices.
用纤维增强机械性能较弱的水凝胶是一种很有前景的途径，可用于获得坚固且坚韧的材料，用于生物医学应用，同时保持良好的细胞环境。由此产生的分级结构重现了天然组织（如关节软骨）的结构元素，纤维直径范围从纳米级到微米级。通过控制纤维直径、取向和孔隙率等特性，可以设计出具有天然组织中观察到的非线性协同力学行为的材料。为了充分利用这些优势，有必要了解纤维增强水凝胶中的结构 - 性能关系。然而，目前能够捕捉其复杂力学性能的模型有限。大多数报道的纤维增强水凝胶包含通过静电纺丝获得的纤维，这对纤维支架的空间控制有限，并限制了系统力学测试研究的范围。尽管如此，诸如熔体静电纺丝和生物打印等新的制造技术已经出现，这使得对纤维沉积的控制增加，并为未来研究特定结构特征对力学性能的影响提供了潜力。因此，在本综述中，我们利用坚韧水凝胶和纤维增强复合材料的设计原理，探讨纤维增强水凝胶的力学，以及其从复制生物组织的特定特征到更复杂结构的设计和制造的演变。通过强调这些领域之间的重叠，可以确定有效生物医学装置开发中仍然存在的挑战和机遇。
