The architecture and surface modifications have been regarded as effective methods to enhance the biological response of biomaterials in bone tissue engineering. The porous architecture of the implantation was essential conditions for bone regeneration. Meanwhile, the design of biomimetic hydroxyapatite (HAp) coating on porous scaffolds was demonstrated to strengthen the bioactivity and stimulate osteogenesis. However, bioactive bio-ceramics such as β-tricalcium phosphate (β-TCP) and calcium silicate (CS) with superior apatite-forming ability were reported to present better osteogenic activity than that of HAp. Hence in this study, 3D-printed interconnected porous bioactive ceramics β-TCP/CS scaffold was fabricated and the biomimetic HAp apatite coating were constructed in situ via hydrothermal reaction, and the effects of HAp apatite layer on the fate of mouse bone mesenchymal stem cells (mBMSCs) and the potential mechanisms were explored. The results indicated that HAp apatite coating enhanced cell proliferation, alkaline phosphatase (ALP) activity, and osteogenic gene expression. Furthermore, PI3K/AKT/mTOR signaling pathway is proved to have an important impact on cellular functions. The present results demonstrated that the key molecules of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT) and mammalian target of rapamycin (mTOR) were activated after the biomimetic hydroxyapatite coating were constructed on the 3D-printed ceramic scaffolds. Besides, the activated influence on the protein expression of Runx2 and BMP2 could be suppressed after the treatment of inhibitor HY-10358. In vivo studies showed that the constructed HAp coating promoted bone formation and strengthen the bone quality. These results suggest that biomimetic HAp coating constructed on the 3D-printed bioactive composite scaffolds could strengthen the bioactivity and the obtained biomimetic multi-structured scaffolds might be a potential alternative bone graft for bone regeneration.

结构和表面修饰被认为是增强骨组织工程中生物材料生物响应的有效方法。植入物的多孔结构是骨再生的必要条件。同时，在多孔支架上设计的仿生羟基磷灰石（HAp）涂层被证明可以增强生物活性并刺激成骨。然而，据报道，具有优异磷灰石形成能力的生物活性生物陶瓷，如 β-磷酸三钙 (β-TCP) 和硅酸钙 (CS) 具有比 HAp 更好的成骨活性。因此，在本研究中，制造了 3D 打印的互连多孔生物活性陶瓷 β-TCP/CS 支架，并原位构建了仿生 HAp 磷灰石涂层。通过水热反应，探讨了HAp磷灰石层对小鼠骨间充质干细胞（mBMSCs）命运的影响及其潜在机制。结果表明，HAp 磷灰石涂层增强了细胞增殖、碱性磷酸酶 (ALP) 活性和成骨基因表达。此外，PI3K/AKT/mTOR信号通路被证明对细胞功能具有重要影响。目前的结果表明，在 3D 打印陶瓷支架上构建仿生羟基磷灰石涂层后，磷脂酰肌醇 3-激酶 (PI3K)、蛋白激酶 B (AKT) 和哺乳动物雷帕霉素靶蛋白 (mTOR) 的关键分子被激活。此外，抑制剂 HY-10358 处理后可抑制对 Runx2 和 BMP2 蛋白表达的激活影响。体内研究表明，构建的 HAp 涂层促进骨形成并增强骨质量。这些结果表明，在 3D 打印的生物活性复合支架上构建的仿生 HAp 涂层可以增强生物活性，所获得的仿生多结构支架可能是骨再生的潜在替代骨移植物。