Bone tissue engineering (BTE) has proven to be a promising strategy for bone defect repair. Due to its excellent biological properties, gelatin methacrylate (GelMA) hydrogels have been used as bioinks for 3D bioprinting in some BTE studies to produce scaffolds for bone regeneration. However, applications for load-bearing defects are limited by poor mechanical properties and a lack of bioactivity. In this study, 3D printing technology was used to create nano-attapulgite (nano-ATP)/GelMA composite hydrogels loaded into mouse bone mesenchymal stem cells (BMSCs) and mouse umbilical vein endothelial cells (MUVECs). The bioprintability, physicochemical properties, and mechanical properties were all thoroughly evaluated. Our findings showed that nano-ATP groups outperform the control group in terms of printability, indicating that nano-ATP is beneficial for printability. Additionally, after incorporation with nano-ATP, the mechanical strength of the composite hydrogels was significantly improved, resulting in adequate mechanical properties for bone regeneration. The presence of nano-ATP in the scaffolds has also been studied for cell-material interactions. The findings show that cells within the scaffold not only have high viability but also a clear proclivity to promote osteogenic differentiation of BMSCs. Besides, the MUVECs-loaded composite hydrogels demonstrated increased angiogenic activity. A cranial defect model was also developed to evaluate the bone repair capability of scaffolds loaded with rat BMSCs. According to histological analysis, cell-laden nano-ATP composite hydrogels can effectively improve bone regeneration and promote angiogenesis. This study demonstrated the potential of nano-ATP for bone tissue engineering, which should also increase the clinical practicality of nano-ATP.

骨组织工程（BTE）已被证明是一种很有前途的骨缺损修复策略。由于其优异的生物学特性，甲基丙烯酸明胶 (GelMA) 水凝胶已在一些 BTE 研究中用作 3D 生物打印的生物墨水，以生产用于骨再生的支架。然而，承载缺陷的应用受到机械性能差和缺乏生物活性的限制。在这项研究中，3D 打印技术被用于制造纳米凹凸棒石 (nano-ATP)/GelMA 复合水凝胶，加载到小鼠骨间充质干细胞 (BMSCs) 和小鼠脐静脉内皮细胞 (MUVECs) 中。对生物印刷性、物理化学性质和机械性能进行了全面评估。我们的研究结果表明，纳米 ATP 组在可印刷性方面优于对照组，表明纳米 ATP 对可印刷性有益。此外，在掺入纳米 ATP 后，复合水凝胶的机械强度显着提高，从而为骨再生提供了足够的机械性能。还研究了支架中存在的纳米 ATP 的细胞-材料相互作用。研究结果表明，支架内的细胞不仅具有高活力，而且具有明显的促进骨髓间充质干细胞成骨分化的倾向。此外，负载 MUVECs 的复合水凝胶表现出增加的血管生成活性。还开发了颅骨缺损模型来评估装载大鼠 BMSC 的支架的骨修复能力。根据组织学分析，载有细胞的纳米ATP复合水凝胶可有效改善骨再生，促进血管生成。