Evaluation of bone regeneration by porous alpha-tricalcium phosphate/atelocollagen sponge composite in rat calvarial defects

Abstract

Purpose

Both atelocollagen and alpha-tricalcium phosphate (α-TCP) particles are widely applied as bone graft materials. In this study, we combined atelocollagen and porous α-TCP particles to form an α-TCP/atelocollagen composite sponge (α-TCP/CS), and we evaluated its effects on bone regeneration in rat calvarial defects.

Materials and methods

α-TCP granules were mixed with a collagen solution. The mixture was poured into plastic molds and then frozen to −80 °C and freeze-dried for 24 h. The composites were then cross-linked in vacuo at 140 °C for 24 h. The obtained composites were characterized by XRD and SEM and observed using micro-CT and histological analysis.

Results

In vivo micro-CT images at 2, 4, and 6 weeks after surgery showed that in the α-TCP/CS group, the bone volume, bone mineral density, and bone mineral content were higher than those in the groups with only atelocollagen and without scaffolds at 6 weeks after surgery. Histological analysis showed that α-TCP was completely absorbed, and new bone that was continuous along the original bone was observed.

Conclusion

This study demonstrated that composite sponges created using porous α-TCP particles and atelocollagen were sufficiently adaptable for treating bone defects.

Keywords:

• Porous α-tricalcium phosphate
• Collagen sponge composite
• Bone tissue engineering
• Rat calvarial defects

Acknowledgments

The authors express their sincere gratitude to Taihei Chemical Industrial Co., Ltd. (Osaka, Japan), for providing the α-TCP particles. The authors also thank Ratoc System Engineering Co., Ltd. (Tokyo, Japan).