Effect of Zn Content on 3D Gel-Printed Porous Mg–Zn Scaffolds for Bone Engineering

This study successfully prepared porous magnesium–zinc (Mg–xZn, x: mass ratio of Zn) scaffolds by the 3D gel-printing method. The effect of adding a large percentage of Zn content on porous Mg–xZn scaffolds was also investigated to comprehensively evaluate the effect of Zn on magnesium alloys. The viscosity of slurry decreases with the increase in Zn content. The optimum solid content of slurry suitable for printing is about 60%. The compressive strength of pure Mg, 0.9Mg–0.1Zn, 0.7Mg–0.3Zn, and 0.5Mg–0.5Zn porous scaffolds were 6.29 MPa, 13.03 MPa, 7.69 MPa, and 6.61 MPa, respectively, meeting the requirements of cancellous bone (0.1–16 MPa). In vitro degradation results showed that the degradation rate of Mg scaffolds can be slowed down by adding the appropriate amount of Zn. The fine and dispersed second-phase precipitation can improve the comprehensive properties of Mg–Zn alloy. This study facilitates a comprehensive evaluation of the effect of Zn content on 3D gel-printed magnesium scaffolds.