It has been established that mechanical stimulation benefits tendon-bone (T-B) healing, and macrophage phenotype can be regulated by mechanical cues; moreover, the interaction between macrophages and mesenchymal stem cells (MSCs) plays a fundamental role in tissue repair. This study aimed to investigate the role of macrophage-mediated MSC chondrogenesis in load-induced T-B healing in depth. C57BL/6 mice rotator cuff (RC) repair model was established to explore the effects of mechanical stimulation on macrophage polarization, transforming growth factor (TGF)-β1 generation, and MSC chondrogenesis within T-B enthesis by immunofluorescence and enzyme-linked immunosorbent assay (ELISA). Macrophage depletion was performed by clodronate liposomes, and T-B healing quality was evaluated by histology and biomechanics. In vitro, bone marrow-derived macrophages (BMDMs) were stretched with CELLOAD-300 load system and macrophage polarization was identified by flow cytometry and quantitative real-time polymerase chain reaction (qRT-PCR). MSC chondrogenic differentiation was measured by histochemical analysis and qRT-PCR. ELISA and qRT-PCR were performed to screen the candidate molecules that mediated the pro-chondrogenic function of mechanical stimulated BMDMs.Aims
Methods
Bone is a dynamic tissue with a quarter of the trabecular and a fifth of the cortical bone being replaced continuously each year in a complex process that continues throughout an individual’s lifetime. Bone has an important role in homeostasis of minerals with non-stoichiometric hydroxyapatite bone mineral forming the inorganic phase of bone. Due to its crystal structure and chemistry, hydroxyapatite (HA) and related apatites have a remarkable ability to bind molecules. This review article describes the accretion of trace elements in bone mineral giving a historical perspective. Implanted HA particles of synthetic origin have proved to be an efficient recruiting moiety for systemically circulating drugs which can locally biomodulate the material and lead to a therapeutic effect. Bone mineral and apatite however also act as a waste dump for trace elements and drugs, which significantly affects the environment and human health. Cite this article:
As one of the heat-stable enterotoxins, Rat MSCs were used to test the effects of SEC2 on their proliferation and osteogenic differentiation potentials. A rat femoral fracture model was used to examine the effect of local administration of SEC2 on fracture healing using radiographic analyses, micro-CT analyses, biomechanical testing, and histological analyses.Objectives
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