Design and Fabrication of Bone Scaffolds With Regular and Irregular Voronoi Architectures: A Comparative Study

Abstract

Bone diseases and consequent defects present a significant challenge in the orthopedics. Synthetic scaffolds mimic bone porose structures and can be substituted in bone defects. In this study, we designed and evaluated four scaffold models with different architectures (regular Voronoi (Rv), irregular Voronoi (Iv), Star (S), and Vintiles (V) structures). Additionally, the scaffolds were designed with four different porosities (50%, 60%, 70%, and 80%), and 16 scaffold models were designed and manufactured using the three-dimensional (3D) printing (3DP) method. The models were fabricated using two photosensitive resins (50% PLA-Pro resin and 50% P-CROWN [zirconia and ceramic]). Thus, the models’ mechanical properties were tested using compression tests. The results showed porosity plays an essential role in scaffold mechanical behavior. Moreover, the architecture was effective in the mechanical performance of the models. The elastic modulus of the models was 4–30 MPa, which is close to trabecular bone mechanical properties. The S-50 model showed a maximum stress of 17.75 MPa, which was 20 times higher than the S-80 model. Similar results were visible in other groups of scaffolds. In all four groups, 50% and 80% porosity scaffolds showed the highest and lowest mechanical strength, respectively. The results of this study showed that the Voronoi structure mimics bone morphology with a stochastic porosity and demonstrated a mechanical property similar to the scaffold with regular structures, which confirms its compatibility with bone tissue engineering. The outcomes of this study shed more light on scaffold design and fabrication for bone defects.