ObjectiveTo review the recent research progress of the regulatory mechanisms of osteoclast (OC) formation and functions. MethodsThe related literature on OC formation, activation, and functions was reviewed, analyzed, and summarized. ResultsMacrophage colony stimulating factor and receptor activator of nuclear factor-κB ligand are essential cytokines which regulate all aspects of OC formation and functions. In additional to mediating bone resorption, OCs also partici pate in regulation of osteoblast formation and immune responses. ConclusionThe researches on the regulation of OC formation and functions have further revealed the destruction mechanisms of various kinds of bone diseases, which will facil itate to find more suitable biological targets for cl inical therapy.
ObjectiveTo review the role and mechanism of protein factors in bone remodeling, and provides theoretical basis for further elucidating the pathogenesis and clinical treatment of bone-related diseases. MethodsThe relevant research results at home and abroad in recent years were extensively consulted, analyzed, and summarized. ResultsBone remodeling is an important physiological process to maintain bone homeostasis. Protein, as an important stimulator in bone remodeling, regulates the balance between bone resorption and bone formation. ConclusionAt present, the research on the mechanism of protein in bone remodeling is insufficient. Therefore, it is necessary to further study the specific time, process, and interaction network of protein in bone remodeling, and to confirm its mechanism in bone remodeling, so as to reveal and treat the pathogenesis of bone-related diseases.
The stiffness of an ideal fracture internal fixation implant should have a time-varying performance, so that the fracture can generate reasonable mechanical stimulation at different healing stages, and biodegradable materials meet this performance. A topology optimization design method for composite structures of fracture internal fixation implants with time-varying stiffness is proposed, considering the time-dependent degradation process of materials. Using relative density and degradation residual rate to describe the distribution and degradation state of two materials with different degradation rates and elastic modulus, a coupled mathematical model of degradation simulation mechanical analysis was established. Biomaterial composite structures were designed based on variable density method to exhibit time-varying stiffness characteristics. Taking the bone plate used for the treatment of tibial fractures as an example, a composite structure bone plate with time-varying stiffness characteristics was designed using the proposed method. The optimization results showed that material 1 with high stiffness formed a columnar support structure, while material 2 with low stiffness was distributed at the degradation boundary and inside. Using a bone remodeling simulation model, the optimized bone plates were evaluated. After 11 months of remodeling, the average elastic modulus of callus using degradable time-varying stiffness plates, titanium alloy plates, and stainless steel plates were 8 634 MPa, 8 521 MPa, and 8 412 MPa, respectively, indicating that the use of degradable time-varying stiffness plates would result in better remodeling effects on the callus.