Bone Regeneration with a Collagen Model Polypeptides/Alpha-Tricalcium Phosphate Sponge in a Canine Tibia Defect Model Author names

Introduction: We evaluated the effects of synthesized collagen model polypeptides consisting of a proline-hydroxyproline-glycine (poly(PHG)) sequence combined with porous alpha-tricalcium phosphate (α-TCP) particles on bone formation in a canine tibia defect model. Materials and Methods: The porous α-TCP particles were mixed with a poly(PHG) solution, and the obtained sponge was then cross-linked and characterized by X-ray diffraction and scanning electron microscopy (SEM). Tibia defects were analyzed in 12 healthy beagles using micro-computed tomography and histological evaluation. Results: At 2 and 4 weeks, the volume density of new bone was higher in the poly(PHG)/α-TCP group than poly(PHG) alone group (p < 0.05); however, there was no difference at 8 weeks (p > 0.05). Histological evaluation at 4 weeks after implantation revealed that the poly(PHG) had degraded and newly formed bone was present on the surface of the α-TCP particles. At 8 weeks, continuous cortical bone formation with a Haversian structure covered the top of the bone defects in both groups. Conclusion: This study demonstrates that the composite created using porous α-TCP particles and poly(PHG) is sufficiently adaptable for treating bone defects.