Three-Dimensional Printing of Calcium Carbonate/Hydroxyapatite Scaffolds at Low Temperature for Bone Tissue Engineering

Three-dimensional (3D) printing technology has been applied to fabricate bone tissue engineering scaffolds for a wide range of materials with precisely control over scaffold structures. Coral is a potential bone repair and bone replacement material. Due to the natural source limitation of coral, we developed a fabrication protocol for 3D printing of calcium carbonate (CaCO₃) nanoparticles for coral replacement in the application of bone tissue engineering. Up to 80% of CaCO₃ nanoparticles can be printed with high resolution using poly-l-lactide as a blender. The scaffolds were subjected to a controlled hydrothermal process for incomplete conversion of carbonate to phosphate to produce CaCO₃ scaffold covered by hydroxyapatite (HA) to modify the biocompatibility and degradation of CaCO₃/HA scaffolds. X-ray diffraction and Fourier transform infrared spectroscopy showed that HA was converted and attached to the surface of the scaffold, and the surface morphology and microstructure were studied using a scanning electron microscope. To confirm the bone regeneration performance of the scaffold, cell proliferation and osteogenic differentiation of MC3T3 cells on the scaffold were evaluated. In addition, in vivo experiments showed that CaCO₃/HA scaffolds can promote bone growth and repairing process and has high potential in bone tissue engineering. ClinicalTrials.gov ID: SH9H-2020-A603.