Bone tissue reactions to apatite-based materials: influence of material composition and morphology

2019 Fiscal Year Final Research Report

• Project/Area Number: 19K21383
• Project/Area Number (Other): 18H06295 (2018)
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund (2019); Single-year Grants (2018)
• Review Section: 0907:Oral science and related fields
• Research Institution: Kyushu University
• Principal Investigator: Kishida Ryo 九州大学, 歯学研究院, 助教 (90823211)
• Project Period (FY): 2018-08-24 – 2020-03-31
• Keywords: 炭酸アパタイト / 骨補填材 / 骨伝導性 / 骨置換性 / ハニカム

Outline of Final Research Achievements

The present study investigated bone tissue reactions of honeycomb scaffolds composed of hydroxyapatite (HAp) and carbonate apatite (CO3Ap) through in vitro (using osteoblastic cell lines) and in vivo (implanted in femoral bone defects) evaluations. In vitro experiments showed approximately the twice expression of early marker of osteoblastic differentiation for CO3Ap cases with respect to the HAp cases. In vivo experiments showed that CO3Ap cases were superior to HAp cases in terms of bone maturation with concomitant material resorption (at 12 weeks postsurgery).
The present study also investigated influence of macropore size of CO3Ap honeycomb scaffolds on new bone formation (in vivo evaluation). The comparative study between 100, 200, and 300 μm of macropore sizes showed remarkable new bone formation for 300 μm cases (at 4 weeks postsurgery).

Free Research Field

生体材料

Academic Significance and Societal Importance of the Research Achievements

超高齢社会を迎えた我が国では健康寿命の延伸が課題となっており、大腿骨近位部骨折をはじめとする高齢者の運動器障害リスクに対応するための機能性材料開発が求められている。本研究では、自家骨移植など侵襲性の高い治療法への依存から脱却しうる人工骨材料として、骨の無機成分と同様の炭酸アパタイトを組成とするハニカム構造体を提案し、古くから臨床応用されてきた水酸アパタイトとの比較を行い、生体反応評価を通して炭酸アパタイトの有用性を示すことができた。