Monolithic copper-doped carbonated apatite synthesized at low-temperature exhibits in vitro antibacterial effect and in vivo bone regenerative properties

Copper (Cu) is a promising dopant for synthetic bone substitutes due to its antibacterial and pro-angiogenic properties. In this study, we synthesized monolithic carbonated apatite (CO₃Ap) doped with Cu²⁺ ions using a low-temperature dissolution-precipitation approach, avoiding high-temperature processing and phase decomposition. The resulting Cu-CO₃Ap scaffolds retained a single-phase apatitic structure and exhibited compositional homogeneity, low crystallinity, and interconnected porosity. The highest Cu content (4.45 ± 0.56 mass %) achieved ∼95 % in vitro bacterial growth inhibition against Staphylococcus epidermidis. In vivo implantation in rabbit femoral defects demonstrated comparable bone regeneration between undoped and Cu-doped CO₃Ap groups, confirming biocompatibility and osteoconductivity. These findings suggest that low-temperature Cu incorporation into CO₃Ap enables the development of antibacterial bone scaffolds without compromising regenerative potential.