Optimization of TCP/HAP ratio for better properties of calcium phosphate scaffold via selective laser sintering

Calcium phosphate ceramics are considered as the most promising materials for bone tissue engineering due to their excellent biocompatibility and bioactivity. In the paper, porous calcium phosphate scaffolds were prepared via selective laser sintering with various weight ratios of TCP/HAP (0/100, 10/90, 30/70, 50/50, 70/30 and 100/0) powders. Furthermore the effect of phase composition on biological and mechanical properties of the scaffold was investigated. The results showed that both the fracture toughness and compressive strength increased with increasing content of TCP from 0 to 30 wt.%, and then dropped with a further increasing content of TCP. The scaffold made of TCP/HAP with a ratio of 30/70 exhibited the optimum fracture toughness (1.33 MPa m1/2) and compressive strength (18.35 MPa). After the scaffolds were soaked in SBF for 7 days, the apatite agglomerates formed on the surface of the scaffolds and the dissolution rate of the scaffolds increased with the increasing content of the TCP. In vitro cell culture indicated that a balance between biological stability and biodegradation rate was helpful for cell adherence and proliferation. It was concluded that the scaffold sintered with TCP/HAP(30/70) performed with optimum mechanical and biological properties.