Mechanical, in vitro and in vivo characterization of 3D-printed photo crosslinking acrylic/nano ZnO biocomposites for bone tissue engineering

Bone is a highly vascularized tissue and self-repairing organ. However, the bone tissue may not be able to heal itself, especially when the injury size is higher than the critical size of the bone defect. Bone tissue engineering (BTE) is a well-recognized and successful approach to enhancing the remodeling process of diseased bone tissue. In this study, initial attention is focused on investigating the mechanical response of nanocomposites-based scaffolds. Photo crosslinking acrylic (PCA) resin and different weight percentages of nanoparticles of zinc oxide (nZnO) were used to make the nanocomposites using stereolithography (SLA) as a 3D printing technology. Here, the influence of nZnO on the mechanical response of the specimens was investigated under tension, compression and bending conditions. The results of these tests suggest that samples containing 1 wt% of nZnO exhibit the highest strength values under the various loading conditions used. Porous scaffolds, with a honeycomb pore shape, were then manufactured using 1 wt% of nZnO. In vitro bioactivity, in vivo biocompatibility, FTIR analysis, scanning electron microscope (SEM) morphological, X-ray radiological, and histopathological analysis were performed. Finally, it is suggested that the high osteogenesis of the 3D-printed porous scaffolds investigated makes it a promising and effective candidate for bone infection treatment.