Immediate to short-term inflammatory response to biomaterial implanted in calvarium of mice

Scaffolds made of biodegradable materials play a very important role in repairing bone defects. Our study was conducted with the aim of investigating inflammation, vascular changes, and tissue necrosis after the placement of 3D printed scaffolds composed of beta-tricalcium phosphate (TCP-13) on the calvarial bone defect of mice. Eight samples of scalp tissue in mice were examined in four groups (one-week control, two-week control, one-week experiment, and two-week experiment). Mice with routine bone defects were selected as the control group and mice with bone defects with 13-TCP scaffolds were selected as the experimental group (TCP). The groups were evaluated in terms of inflammatory cells, osteoblast and osteoclast cells, vascular changes, and the number of resorption pit and empty lacuna. The results demonstrated a decrease in inflammatory cells and an increase in osteoclast and osteoblast cells in bone defect sites placed with TCP-13 scaffolds (p<0.05). The results of histological staining showed pit resorption and further vascularization in the place of TCP-13 scaffolds, but these changes were not statistically significant (p>0.05). Examining the number of empty lacunae in the bone defect site showed that TCP-13 could significantly reduce the number of these lacunae in the bone defect sites placed with TCP-13 scaffolds (p<0.05). 3D printed scaffolds composed of TCP-13 that were implanted in bone defect sites were effective in reducing the inflammatory responses, emptying lacunae and increasing bone regeneration.