Ultra-lightweight ceramic scaffolds with simultaneous improvement of pore interconnectivity and mechanical strength

The high porosity and interconnectivity of scaffolds are critical for nutrient transmission in bone tis-sue engineering but usually lead to poor mechanical properties. Herein, a novel method that combines acid etching (AE) with selective laser sintering (SLS) and reaction bonding (RB) of Al particles is pro-posed to realize highly improved porosity, interconnectivity, mechanical strength, and in vitro bioactivity in 3D Al2O3 scaffolds. By controlling the oxidation and etching behaviors of Al particles, a tunable hol-low spherical feature can be obtained, which brings about the distinction in compressive response and fracture path. The prevention of microcrack propagation on the in situ formed hollow spheres results in unique near elastic buckling rather than traditional brittle fracture, allowing an unparalleled compressive strength of 3.72 +/- 0.17 MPa at a high porosity of 87.7% +/- 0.4% and pore interconnectivity of 94.7% +/- 0.4%. Furthermore, scaffolds with an optimized pore structure and superhydrophilic surface show excellent cell proliferation and adhesion properties. Our findings offer a promising strategy for the coexistence of out-standing mechanical and biological properties, with great potential for tissue engineering applications.(c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.