Conventional hydrogels often suffer from weak and fragile natures, limiting their uses in mechanically demanding areas. By contrast, spider silk hold impressive strength and toughness owing to its hierarchical structure. Inspired by spider dragline fiber, the boundaries of conventional hydrogels are broken by introducing hierarchical structures in chitosan fibrous hydrogels (FHCS) via a top‐down multidimensional engineering strategy. Each level of hierarchical structure is introduced in different approaches: macroscopic fibers are fabricated via electrospinning; microscopic fibrillar structures are introduced based on “sea‐islands” phase separation structure; chitosan anhydrous crystallites at the molecular level are induced by hydrogen bonding reconstruction. Through this strategy, the resulting hierarchical FHCS exhibits extreme mechanical properties (fracture strength: 47.0 ± 2.4 MPa; Young's modulus: 5.6 ± 2.4 MPa; fracture toughness: 12.3 ± 1.5 MJ m−3), simulating the mechanical properties of cartilage tissue. FHCS also shows good biocompatibility, biodegradability, and modulation on cell spreading and phenotypes via mechanotransduction pathway. Overall, FHCS emerges as a promising material in the mechanically demanding areas of biomedical fields. Besides, the top‐down multidimensional engineering strategy provides fresh perspectives for creating hierarchical materials.

中文翻译：

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通过自上而下的多维工程策略，受 Spider Silk 启发的具有极强稳定性的分层纤维水凝胶


传统的水凝胶通常具有脆弱和脆弱的特点，限制了它们在机械要求苛刻的领域的使用。相比之下，蜘蛛丝由于其分层结构而具有令人印象深刻的强度和韧性。受蜘蛛式拉铲纤维的启发，通过自上而下的多维工程策略在壳聚糖纤维水凝胶 （FHCS） 中引入分层结构，打破了传统水凝胶的界限。每个层次结构都以不同的方式引入：宏观纤维是通过静电纺丝制造的;基于“海岛”相分离结构引入了微观纤维结构;壳聚糖无水微晶在分子水平上是通过氢键重建诱导的。通过这种策略，得到的分层 FHCS 表现出极高的机械性能（断裂强度：47.0 ± 2.4 MPa;杨氏模量：5.6 ± 2.4 MPa;断裂韧性：12.3 ± 1.5 MJ m-3），模拟软骨组织的机械性能。FHCS 还通过机械转导途径显示出良好的生物相容性、生物降解性以及对细胞扩散和表型的调节。总体而言，FHCS 在生物医学领域的机械要求领域成为一种很有前途的材料。此外，自上而下的多维工程策略为创建分层材料提供了新的视角。