Nanofiber-induced hierarchically-porous magnesium phosphate bone cements accelerate bone regeneration by inhibiting Notch signaling

• Published in: Bioactive materials Vol. 37; pp. 459 - 476
• Main Authors: Chen, Jingteng, Yu, Ling, Gao, Tian, Dong, Xiangyang, Li, Shiyu, Liu, Yinchu, Yang, Jian, Xia, Kezhou, Yu, Yaru, Li, Yingshuo, Wang, Sen, Fan, ZhengFu, Deng, Hongbing, Guo, Weichun
• Format: Journal Article
• Language: English
• Published: China Elsevier B.V 01.07.2024; KeAi Publishing Communications Ltd; KeAi Publishing; KeAi Communications Co., Ltd
• Subjects: Biocompatibility; Biodegradability; Biodegradation; Bone cements; Bone growth; Bone implants; Bone marrow; Bone matrix; Bone regeneration; Calvaria; Cbfa-1 protein; Cell proliferation; Cement; Critical-sized bone defects; Defects; Differentiation (biology); Extracellular matrix; Magnesium; Magnesium oxide; Magnesium phosphate; Magnesium phosphate bone cement; Mechanical properties; Nanofibers; Notch signaling pathway; Nutrients; Osteogenesis; Permeability; Polymethyl methacrylate; Porosity; Pseudopodia; Regeneration; Regeneration (physiology); Signal transduction; Silk fibroin; Silk fibroin nanofibers; Spectrum analysis; Stem cells; Superconductors (materials); Tissue engineering; Vascularization; Wnt protein; Critical-sized bone defects; Magnesium phosphate bone cement; Notch signaling pathway; Bone regeneration; Silk fibroin nanofibers
• ISSN: 2452-199X; 2097-1192; 2452-199X
• DOI: 10.1016/j.bioactmat.2024.03.021

Magnesium phosphate bone cements (MPC) have been recognized as a viable alternative for bone defect repair due to their high mechanical strength and biodegradability. However, their poor porosity and permeability limit osteogenic cell ingrowth and vascularization, which is critical for bone regeneration. In the current study, we constructed a novel hierarchically-porous magnesium phosphate bone cement by incorporating extracellular matrix (ECM)-mimicking electrospun silk fibroin (SF) nanofibers. The SF-embedded MPC (SM) exhibited a heterogeneous and hierarchical structure, which effectively facilitated the rapid infiltration of oxygen and nutrients as well as cell ingrowth. Besides, the SF fibers improved the mechanical properties of MPC and neutralized the highly alkaline environment caused by excess magnesium oxide. Bone marrow stem cells (BMSCs) adhered excellently on SM, as illustrated by formation of more pseudopodia. CCK8 assay showed that SM promoted early proliferation of BMSCs. Our study also verified that SM increased the expression of OPN, RUNX2 and BMP2, suggesting enhanced osteogenic differentiation of BMSCs. We screened for osteogenesis-related pathways, including FAK signaing, Wnt signaling and Notch signaling, and found that SM aided in the process of bone regeneration by suppressing the Notch signaling pathway, proved by the downregulation of NICD1, Hes1 and Hey2. In addition, using a bone defect model of rat calvaria, the study revealed that SM exhibited enhanced osteogenesis, bone ingrowth and vascularization compared with MPC alone. No adverse effect was found after implantation of SM in vivo. Overall, our novel SM exhibited promising prospects for the treatment of critical-sized bone defects. •The addition of silk fibroin (SF) nanofibers to magnesium phosphate bone cement (MPC) resulted in enhanced mechanical properties, neutralized the strongly alkaline environment, and more importantly, created a heterogeneous and hierarchical pore structure.•The SF-embedded MPC (SM) promoted the adhesion, proliferation, and osteogenic differentiation of bone marrow stem cells in vitro.•SM aided the process of bone regeneration by suppressing the Notch signaling pathway.•SM exhibited enhanced osteogenesis, bone ingrowth and vascularization in vivo compared with MPC alone.