Multi-material 3D printing technologies that resolve features at different lengths down to the microscale open new avenues for regenerative medicine, particularly in the engineering of tissue interfaces. Herein, extrusion printing of a bone-biomimetic ceramic ink and melt electrowriting (MEW) of spatially organized polymeric microfibres are integrated for the biofabrication of an osteochondral plug, with a mechanically reinforced bone-to-cartilage interface. A printable physiological temperature-setting bioceramic, based on α-tricalcium phosphate, nanohydroxyapatite and a custom-synthesized biodegradable and crosslinkable poloxamer, was developed as bone support. The mild setting reaction of the bone ink enabled us to print directly within melt electrowritten polycaprolactone meshes, preserving their micro-architecture. Ceramic-integrated MEW meshes protruded into the cartilage region of the composite plug, and were embedded with mechanically soft gelatin-based hydrogels, laden with articular cartilage chondroprogenitor cells. Such interlocking design enhanced the hydrogel-to-ceramic adhesion strength >6.5-fold, compared with non-interlocking fibre architectures, enabling structural stability during handling and surgical implantation in osteochondral defects ex vivo. Furthermore, the MEW meshes endowed the chondral compartment with compressive properties approaching those of native cartilage (20-fold reinforcement versus pristine hydrogel). The osteal and chondral compartment supported osteogenesis and cartilage matrix deposition in vitro, and the neo-synthesized cartilage matrix further contributed to the mechanical reinforcement at the ceramic-hydrogel interface. This multi-material, multi-scale 3D printing approach provides a promising strategy for engineering advanced composite constructs for the regeneration of musculoskeletal and connective tissue interfaces.

中文翻译：

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结合多尺度3D打印技术来设计增强型水凝胶-陶瓷界面。

多材料3D打印技术可解决不同长度的特征，直至微观尺度，为再生医学开辟了新途径，尤其是在组织界面工程方面。本文中，仿生骨陶瓷油墨的挤出印刷和空间组织的聚合物微纤维的熔体电写（MEW）集成在一起，用于具有机械增强的骨-软骨界面的骨软骨栓塞的生物制造。基于α-磷酸三钙，纳米羟基磷灰石和定制合成的可生物降解和可交联的泊洛沙姆的可印刷的生理温度定型生物陶瓷被开发为骨载体。骨墨水的轻微凝固反应使我们能够直接在熔融的电沉积聚己内酯网孔内进行打印，从而保留了它们的微结构。陶瓷集成的MEW网格突出到复合材料栓塞的软骨区域，并嵌入有机械性软明胶基水凝胶，其中装有关节软骨软骨细胞。与非互锁纤维结构相比，这种互锁设计将水凝胶与陶瓷的粘合强度提高了> 6.5倍，从而在离体骨软骨缺损的处理和手术植入过程中实现了结构稳定性。此外，MEW网格赋予软骨隔室以接近天然软骨的压缩特性（20倍增强剂与原始水凝胶的结合）。骨和软骨腔在体外支持成骨和软骨基质沉积，新合成的软骨基质进一步促进了陶瓷-水凝胶界面的机械增强。这种多材料，多尺度的3D打印方法为工程设计先进的复合材料结构（用于骨骼肌肉和结缔组织界面的再生）提供了一种有前途的策略。