Effects of pore distribution and chemistry on physical, mechanical, and biological properties of tricalcium phosphate scaffolds by binder-jet 3D printing

Porous tricalcium phosphate (TCP) scaffolds are becoming more and more important for treating musculoskeletal diseases. With the maturation of 3D printing (3DP) technology in the past two decades, porous TCP scaffolds can also be easily prepared with complex design and high dimensional accuracy. However, the mechanical and biological properties of porous TCP scaffolds prepared by 3D printing still need improvements. In this study, novel 3D printed TCP and MgO/ZnO-TCP scaffolds were prepared by an binder-jet 3D printer. Scaffolds had a dense core and porous surface feature with a designed pore size of 500 μm and a designed porosity of 18%. After printing, scaffolds were sintered in a muffle furnace at 1250 °C. The presence of MgO and ZnO increased the surface area of TCP from 1.18 ± 0.01 m2/g to 2.65 ± 0.02 m2/g, the bulk density from 37.89 ± 0.83% to 50.82 ± 1.10%, and the compressive strength from 17.94 ± 1.65 MPa to 27.46 ± 2.63 MPa. Enhanced osteoblast proliferation was shown in doped 3D printed TCP scaffolds compared to the pure 3DP TCP. In addition, the use of 3D printing as well as dense core and porous surface design enhanced the surface roughness and osteoblast proliferation of TCP scaffolds. This novel 3D printed MgO/ZnO-TCP scaffold shows enhanced mechanical and biological properties, which is promising for orthopedic and dental applications.