3D printing magnesium-doped wollastonite/β-TCP bioceramics scaffolds with high strength and adjustable degradation

Mechanical strength of bioceramic scaffolds is a problem to treat the load bearing bone defects. We developed the Mg-doping wollastonite (CSi-Mg)-based scaffolds with high strength via 3D printing technology. The effect of pore size, β-tricalcium phosphate (β-TCP) content (x%), and heating schedule on the strength of scaffolds were investigated systematically. Incorporation of β-TCP could readily adjust the sintering properties of the CSi-Mg scaffolds and the scaffolds with high (20-30%) and low (10-20%) β-TCP possess much high strength (80-100 MPa or 120-140 MPa) after undergoing one- or two-step sintering. Meanwhile, the CSi-Mg/TCPx (x = 10, 20) with medium-pore (∼320 μm) had over 100 MPa in compression and ∼52% in porosity. In particular, the composite scaffolds maintained appreciable strength (over 50 MPa) after immersion in Tris buffer for a long time stage (6 weeks). These findings demonstrate that the CSi-Mg/TCPx scaffolds are promising for treating some challengeable bone defects, especially for load-bearing bone repair.