Cyclic mechanical stretch pre‐stimulated bone marrow mesenchymal stem cells promote the healing of infected bone defect in a mouse model

Abstract

Cyclic mechanical stretch (CMS) is an effective method to accelerate mesenchymal stem cells (MSCs) differentiation. Here, CMS pre‐stimulated bone marrow MSCs (CMS‐BMSCs) was investigated, characterized and evaluated the therapeutic potential of CMS‐BMSCs on the treatment of infected bone defect in mouse model. BMSCs were obtained from C57BL/6J mice and then subjected to CMS. The osteogenic differentiation capacity of BMSCs was evaluated by alkaline phosphatase (ALP) assay, Alizarin Red staining, qRT‐PCR, and Western blot. The pre‐stimulated BMSCs were transplanted into infected bone defect mice, osteogenesis, antibacterial effects, and inflammatory responses were examined. CMS significantly increased ALP activity and the expression of osteoblastic genes (col1a1, runx2, and bmp7) and enhanced osteogenic differentiation and nrf2 expression of BMSCs. Transplantation of CMS pre‐stimulated BMSCs promoted the healing of infected bone defect in mice, enhanced antibacterial effects, and reduced inflammatory responses in the mid‐sagittal section of the fracture callus. CMS pre‐stimulated BMSCs enhance the healing of infected bone defects in a mouse model, suggesting a potential therapeutic strategy for treating infected bone defects.