3D-printed β-TCP/Ti6Al4V composite scaffolds for bone regeneration: Process parameter optimization and evaluation

A β-TCP/Ti6Al4V composite scaffold with interconnected macro porous architecture was fabricated using Direct Ink Writing (DIW). Pluronic F-127 and de-ionized water was used as binder and solvent for ink preparation. The present work was carried out to study the rheological behavior of the composite bioceramic ink and to investigate DIW process parameters such as Ti6Al4V proportion, infill percentage and extrusion pressure. The Box-Behnken response surface methodology, ANOVA, sensitivity, desirability approach are used for the experimental, statistical and numerical optimization of the parameters suitable for DIW. The output responses such as dimensional error of the fabricated scaffold from the original dimensions and compressive strength are considered for multi-objective optimization. The result defined that the optimal values are solid loading 55 %v/v (40 %v/v of β-TCP, 15 %v/v of Ti6Al4V) and 45 %v/v of Pluronic gel, 98 % infill rate and 6.36 bar pressure. The dimensional error and compressive strength of the scaffold printed at the optimized conditions are found as 1.88 % and 19 MPa with macro and micro pores suitable for bone regeneration with satisfactory biocompatibility assed via MTT assay.