Direct Ink Writing (DIW) has demonstrated great potential as a versatile method to 3D print multifunctional structures. In this work, we report the implementation of hydrogel meta-structures using DIW at room temperature, which seamlessly integrate large specific surface areas, interconnected porous characteristics, mechanical toughness, biocompatibility, and water absorption and retention capabilities. Robust but hydrophobic polymers and weakly crosslinked nature-origin hydrogels form a balance in the self-supporting ink, allowing us to directly print complex meta-structures without sacrificial materials and heating extrusion. Mechanically, the mixed bending or stretching of symmetrical re-entrant cellular lattices and the unique curvature patterns are combined to provide little lateral expansion and large compressive energy absorbance when external forces are applied on the printed meta-structures. In addition, we have successfully demonstrated ear, aortic valve conduits and hierarchical architectures. We anticipate that the reported 3D meta-structured hydrogel would offer a new strategy to develop functional biomaterials for tissue engineering applications in the future.

直接墨水书写 (DIW) 作为 3D 打印多功能结构的通用方法已展现出巨大的潜力。在这项工作中，我们报告了在室温下使用 DIW 实现水凝胶元结构，该结构无缝地集成了大比表面积、互连多孔特性、机械韧性、生物相容性以及吸水和保留能力。坚固但疏水的聚合物和弱交联的天然水凝胶在自支撑墨水中形成平衡，使我们能够直接打印复杂的元结构，而无需牺牲材料和加热挤压。在机械方面，对称凹入细胞晶格的混合弯曲或拉伸与独特的曲率图案相结合，当外力施加在印刷的元结构上时，可提供较小的横向膨胀和较大的压缩能量吸收。此外，我们还成功演示了耳朵、主动脉瓣导管和分层架构。我们预计所报道的 3D 元结构水凝胶将为未来开发用于组织工程应用的功能性生物材料提供新策略。