Preparation and Characterization of Digital Coral Hydroxyapatite Artificial Bone Scaffolds Based on 3D Printing

Selective laser sintering (SLS) rapid prototyping (RP) technology enables the fabrication of the specific geometries required for tissue engineering. In this study, digital coral hydroxyapatite (DCHA) scaffolds based on a previously created three-dimensional (3D) computer-aided design (CAD) model were fabricated by SLS-RP technology, which involved sintering a mixture powder of the coral hydroxyapatite (CHA) particles and L-polylactic acid (L-PLA) with different mass ratios. The machining accuracy was evaluated, and the structure and properties of the scaffolds were investigated through dynamic mechanical analysis (DMA), mercury porosimetry, scanning electron microscopy (SEM) and cell culture. The results showed that DCHA scaffolds can be 3D printed from a digital CAD model and that the scaffolds maintain the porous structure of the original coral, whose surface is rough. The machining accuracy of the scaffolds was +0.1 cm. As the proportion of CHA particles increased, the hydrophilicity, porosity and density of the scaffolds gradually increased, while the compressive strength gradually decreased. In addition, the DCHA scaffolds had no negative effect on the cell viability and proliferation. All the results reported in this study suggest that DCHA scaffolds may have potential clinical applications as scaffolds for bone tissue engineering.