Biocompatibility, mechanical strength, three?dimensional complex geometries and interconnected multiscale porosity are current problematic of scaffolds design for applications in bone tissue engineering. Hydroxyapatite (HA) ceramic scaffolds are commonly used as bone graft substitutes because of a chemical composition close to that of the mineral bone inducing high biocompatibility. Design of such scaffolds is a challenge to improve biological properties and extend the applications of HA ceramics in the field of bone tissue engineering (BTE) requiring the use of 3D printing technology and more specifically stereolithography (SLA), i.e. vat photopolymerisation.

The main objective of this study was to elaborate bioceramic scaffolds mimicking human bone architecture especially trabecular bone by additive manufacturing. Particular attention has been paid to the processing and the in vitro properties of 3D bioceramic scaffolds.

Several samples of human tibial bones of 1 cm3 were collected during surgery and scanned by X-Ray microtomography, with a resolution of about 15µm, to generate 3D model database. The 3D model was then sliced and printed with an SLA device. Processing parameters (laser power, laser pass number and layer thickness) were investigating using an experimental design in order to understand their influence on the shaped part (overpolymerisation, thinness of the walls,…). Comparative study between the 3D model and the green part was performed by image analysis in order to determine the accuracy of the construct and to determine the better parameters for 3D printing.

Green parts were sintered with different thermal cycles to optimize the sintering with regard to the full density, the thinness of the walls and the targeted micro-porosity necessary for cell development. Finally, cell culture was performed on bone substrates to investigate proliferation, adhesion and attachment of human bone cells.

This study shows that 3D HA-based bioceramic scaffolds mimicking human bone architecture for BTE could be efficiently developed by additive manufacturing.