Most current hydrogels have weak mechanical properties and unordered structures, which limits their applications. However, soft tissues with highly ordered hierarchical nanocomposite structures exhibit anisotropic mechanical performance and function to adapt the complex environments. Therefore, the introduction of an ordered nanocomposite structure into hydrogel is an effective strategy to endow the hydrogel with superb mechanical strength and excellent anisotropic functions. Here, we develop a method to create anisotropic hydrogels with significantly enhanced mechanical and tribological properties. Based on mussel adhesion chemistry, polydopamine (PDA) was used as a mediator to control the formation of Fe₃O₄ nanoparticles on the surface of montmorillonite (MMT). Subsequently, the obtained PDA-Fe₃O₄-MMT nanohybrids in the polyvinyl alcohol/polyacrylic acid (PVA/PAA) hydrogel matrix were aligned to form an ordered structure using magnetic-induced technology and then frozen in hydrogel form by freezing-thawing and annealing methods. The resulting hydrogels showed an anisotropic microstructure and exhibited outstanding mechanical properties with a tensile strength of 10.65 MPa, toughness of 52.2 MJ/m³, and compressive strength of 4.86 MPa, which is higher than that of the corresponding isotropic hydrogel. More interestingly, the friction coefficient of hydrogel is significantly reduced to as low as 0.038 due to the presence of ordered structure. This work not only improves magnetic induction technology for the preparation of anisotropic hydrogels but also provides a simple and effective method to obtain hydrogels with anisotropic structure, high mechanical strength, and anisotropic properties for potential application in tissue engineering.

目前大多数水凝胶具有较弱的机械性能和无序结构，这限制了它们的应用。然而，具有高度有序分层纳米复合结构的软组织表现出各向异性的机械性能和适应复杂环境的功能。因此，将有序的纳米复合结构引入水凝胶中是赋予水凝胶极好的机械强度和优异的各向异性功能的有效策略。在这里，我们开发了一种方法来制造具有显着增强的机械和摩擦学性能的各向异性水凝胶。基于贻贝粘附化学，聚多巴胺（PDA）被用作介质来控制 Fe ₃ O ₄的形成蒙脱石（MMT）表面的纳米颗粒。随后，获得的 PDA-Fe ₃ O ₄ -MMT 纳米杂化物在聚乙烯醇/聚丙烯酸 (PVA/PAA) 水凝胶基质中使用磁诱导技术排列形成有序结构，然后通过冻融和冷冻以水凝胶形式冷冻。退火方法。所得水凝胶显示出各向异性的微观结构，并表现出优异的机械性能，拉伸强度为 10.65 MPa，韧性为 52.2 MJ/m ³，抗压强度为 4.86 MPa，高于相应的各向同性水凝胶。更有趣的是，由于有序结构的存在，水凝胶的摩擦系数显着降低至 0.038。这项工作不仅改进了制备各向异性水凝胶的磁感应技术，而且为获得具有各向异性结构、高机械强度和各向异性特性的水凝胶在组织工程中的潜在应用提供了一种简单有效的方法。