Biomimetic Rotated Lamellar Plywood Motifs by Additive Manufacturing of Metal Alloy Scaffolds for Bone Tissue Engineering.

Additive manufacturing presents opportunities to treat bone defects using biomimetic tissue scaffolds. Past investigations have explored modulating scaffold mechanical properties through varying materials and geometric motifs. Herein, we applied the rotated plywood structure of bone tissue to a 3D printed scaffold with the goal of improving mechanical performance compared to an orthogonal mesh design commonly used in tissue scaffold applications. The scaffolds were subjected to uniaxial compression followed by scanning electron microscopy and microcomputer tomography. The uniaxial compression test was characterized through elastic modulus (mean 1.32 GPa biomimetic, 0.196 GPa orthogonal, p < 0.001), ultimate compressive strength (mean 16.546 MPa biomimetic, 6.309 MPa orthogonal design, p < 0.001), and ultimate compressive strain values (4.867% biomimetic, 9.000% orthogonal, p < 0.005). Correlation of microfracture imaging to bulk scaffold mode of failure suggest that utilizing the biomimetic plywood design not only improved mechanical performance, but also reduced asymmetrtic buckling, plastic deformation, and fracture propagation similar to bone tissue.