Artificial bioactive materials have received increasing attention worldwide in clinical orthopedics to repair bone defects that are caused by trauma, infections or tumors, especially dedicated to the multifunctional composite effect of materials. In this study, a weakly alkaline, biomimetic and osteogenic, three-dimensional composite scaffold (3DS) with hydroxyapatite (HAp) and nano magnesium oxide (MgO) embedded in fiber (F) of silkworm cocoon and silk fibroin (SF) is evaluated comprehensively for its bone repair potential in vivo and in vitro experiments, particularly focusing on the combined effect between HAp and MgO. Magnesium ions (Mg²⁺) has long been proven to promote bone tissue regeneration, and HAp is provided with osteoconductive properties. Interestingly, the weak alkaline microenvironment from MgO may also be crucial to promote Sprague-Dawley (SD) rat bone mesenchymal stem cells (BMSCs) proliferation, osteogenic differentiation and alkaline phosphatase (ALP) activities. This SF/F/HAp/nano MgO (SFFHM) 3DS with superior biocompatibility and biodegradability has better mechanical properties, BMSCs proliferation ability, osteogenic activity and differentiation potential compared with the scaffolds adding HAp or MgO alone or neither. Similarly, corresponding meaningful results are also demonstrated in a model of distal lateral femoral defect in SD rat. Therefore, we provide a promising 3D composite scaffold for promoting bone regeneration applications in bone tissue engineering.

人工生物活性材料已在全世界范围内日益受到临床骨科的关注，以修复由外伤，感染或肿瘤引起的骨缺损，特别是致力于材料的多功能复合作用。在这项研究中，综合评估了弱碱性，仿生和成骨的三维复合支架（3DS），其中将羟基磷灰石（HAp）和纳米氧化镁（MgO）嵌入蚕茧和丝素蛋白（SF）的纤维（F）中。由于其在体内和体外实验中具有的骨修复潜力，尤其着重于HAp和MgO之间的联合作用。镁离子（Mg ²⁺）长期以来被证明可促进骨组织再生，并且HAp具有骨传导特性。有趣的是，来自MgO的弱碱性微环境对于促进Sprague-Dawley（SD）大鼠骨骼间充质干细胞（BMSC）增殖，成骨细胞分化和碱性磷酸酶（ALP）活性也可能至关重要。与仅添加HAp或MgO或不添加HAp或MgO的支架相比，这种具有优异生物相容性和生物降解性的SF / F / HAp /纳米MgO（SFFHM）3DS具有更好的机械性能，BMSCs增殖能力，成骨活性和分化潜能。类似地，在SD大鼠的股骨远端外侧缺损模型中也证明了相应的有意义的结果。因此，