LAUSR

Carbonate apatite‐coated calcium carbonate (CO3Ap/CaCO3) was fabricated through a dissolution–precipitation reaction using CaCO3 granules as a precursor to accelerate bone replacement based on superior osteoconductivity of the CO3Ap shell, along with Ca2+ release from the CaCO3 core and quicker resorption of the CaCO3 core. In the present study, CaCO3, 10% CO3Ap/CaCO3, 30% CO3Ap/CaCO3, and CO3Ap granules were fabricated and examined histologically to evaluate their potential as bone substitutes. Larger contents of CaCO3 in the granules resulted in higher Ca2+ release and promoted cell proliferation of murine preosteoblasts at 6 days compared with CO3Ap. Interestingly, in a rabbit femur defect model, 10% CO3Ap/CaCO3 induced significantly higher new bone formation and higher material resorption compared with CO3Ap at 8 weeks. Nevertheless, CO3Ap showed a superior osteoconductive potential compared with 10% CO3Ap/CaCO3 at 8 weeks. All tested granules were most likely resorbed by cell mediation including multinucleated giant cell functions. Therefore, we conclude that CO3Ap/CaCO3 has a positive potential for bone tissue engineering based on well‐controlled calcium release, bone formation, and material resorption.