Enhanced healing of rat calvarial defects with 3D printed calcium-deficient hydroxyapatite/collagen/bone morphogenetic protein 2 scaffolds

In this paper, we mainly to evaluate the newly formed bone using the Calcium deficient hydroxyapatite (CDHA)/collagen-based bio-ceramic scaffold as Bone Morphogenetic Protein-2 (BMP-2) carrier in rat calvarial criticalsized bone defect. In the real-time PCR analysis, the CDHA/collagen scaffold loaded rhBMP-2 group showed significantly enhanced results of bone-related gene expression (p < 0.05). In the in vivo study, the micro-CT showed that the main bone formation parameters of percent bone volume and trabecular number of the two experiment groups (CDHA/Collagen (CDHA) group, BV/TV: 14.21 +/- 3.20, Tb.N: 2.37 +/- 0.50; CDHA/Collagen/rhBMP-2(BMP) group, BV/TV: 14.51 +/- 3.12, Tb.N: 2.75 +/- 0.65) were significantly higher than those of the control (Blank, BV/TV: 3.25 +/- 1.25, Tb.N: 0.57 +/- 0.20) group (p < 0.05). Although there was no significant difference between the two experimental groups, the BMP group results were slightly higher than those of the CDHA group (p > 0.05). Moreover, the histological results also supported the micro-CT results. The scaffold of CDHA/collagen seems to be a suitable bio-ceramic carrier loaded rhBMP-2, and appears to enhance new bone formation and bone regeneration in bone defect after implantation.