Mechanical and biological properties of 3D printed bionic porous Gyroid structure implant.

To investigate the mechanical properties and bone integration capability of bionic gradient porosity Gyroid-structured porous implants. We fabricated porous implants using selective laser melting and large particle sandblasting acid etching techniques, and conducted systematic evaluations through mechanical testing and animal experiments. Mechanical tests demonstrated that the elastic modulus of uniform porosity and gradient porosity Gyroid-structured implants were similar after SLA processing, while the yield strength and compressive strength of gradient porosity Gyroid-structured implants were significantly lower than those of uniform porosity structures. However, all mechanical properties of gradient porosity Gyroid-structured implants matched those of human cancellous bone. Histological examination revealed that at 4 weeks post-implantation, the apical region of gradient Gyroid-structured implants exhibited more new tissue formation compared to uniform porosity Gyroid-structured implants, with no significant difference observed in the neck region. At 8 weeks, bone tissue ingrowth was significantly greater in the neck and apical regions of gradient Gyroid-structured implants compared to uniform porosity Gyroid-structured implants. Additionally, no abnormal inflammatory responses were observed on either type of implant surface. Gradient porosity Gyroid-structured implants demonstrated excellent mechanical properties and enhanced bone integration capabilities, providing a reference for the design of novel implants.