Application and Research Progress of Carbonated Hydroxyapatite in Bone Tissue Regeneration.

Carbonated Hydroxyapatite (CHA) has attracted widespread attention in bone tissue regeneration due to its chemical composition and crystal structure, which are similar to natural bone tissue. This review summarizes the basic characteristics of CHA, preparation methods, and advances in its application in bone repair. First, the crystal structure, chemical composition, and the effect of carbonate doping on its physicochemical properties are discussed, focusing on how preparation techniques such as the wet chemical method, sol-gel method, and hydrothermal synthesis regulate CHA's properties. Second, the biological mechanisms of CHA in bone tissue regeneration are outlined, including its role in promoting osteoblast proliferation and differentiation, regulating the bone repair microenvironment, and mediating related signaling pathways (e.g., Wnt/β-catenin and bone morphogenetic protein (BMP)/Smad). Furthermore, the research progress of CHA in repairing cranial, alveolar, and long bone defects is systematically reviewed through animal models and clinical studies to evaluate its bone repair capacity and biocompatibility. In addition, the composite application of CHA with polymers and bioactive glass and its potential development in frontier technologies such as 3D printing and smart drug delivery are discussed. Finally, the challenges in mechanical properties, degradation rate, and preparation processes are analyzed, and the future application prospects of CHA as an intelligent, multifunctional bone repair material are envisaged. This review aims to provide theoretical support and research insights to optimize the design and application of CHA in bone tissue engineering.