Bone formation with functionalized 3D printed poly-ε-caprolactone scaffold with plasma-rich-fibrin implanted in critical-sized calvaria defect of rat

Abstract Background/purpose Space-making is one of the essential factors for bone regeneration in severe bony defect. To test the hypothesis that an appropriately designed scaffold may be beneficial for the bone formation in defect, the new bone formed in the critical-size calvarial defect of rat was examined after implanted with a 3D-printed poly-ɛ-caprolactone (PCL) scaffold, retaining with and without plasma rich fibrin (PRF). Materials and methods Thirty-two rats were divided into four groups (control, PCL, PRF, and PCL-plus-PRF). A custom-made 3D-printed PCL scaffold, 900 μm in pore size, retaining with and without PRF, was implanted into a critical-sized calvarial defect, 6 mm in diameter. Animals were sacrificed at week-4 or 8 after implantation for assessing the new bone formation by dental radiography, micro-computed tomography (μ-CT), and histology. Results By radiography and μ-CT, significantly greater mineralization areas/volumes were observed in defects with 3D-printed scaffold groups compared to that without the scaffold in both two-time points. However, no advantage was found by adding PRF. Histology showed that bone tissues grew into the central zone of the critical defect when 3D-printed PCL scaffold was present. In contrast, for the groups without the scaffolds, new bones were formed mostly along defect borders, and the central zones of the defects were collapsed and healed with thin connective tissue. Conclusion Our results suggest that the use of a 900 μm pore size 3D-printed PCL scaffold may have the potential in facilitating the new bone formation.