Development of new evaluation method for gas cavity formation behavior accompanying biocorrosion of Mg alloys

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H02116
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Medical engineering assessment
• Research Institution: National Institute for Materials Science
• Principal Investigator: YAMAMOTO AKIKO 国立研究開発法人物質・材料研究機構, 機能性材料研究拠点, 上席研究員 (20343882)
• Co-Investigator(Kenkyū-buntansha): 清水 良央 東北大学, 歯学研究科, 助教 (30302152)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 生体吸収性金属材料 / 水素発生 / 空孔形成 / リスク評価

Outline of Final Research Achievements

Biomedical application of magnesium (Mg) alloys for biodegradable metallic devices is widely investigated since they are easily corroded by reacting with water in the body fluid. Recently Mg alloy bone fixture devices are commercialized, but gas cavity formation in the surrounding tissue is reported in their clinical cases. Some of them resulted in the delay of fracture healing. Gas cavity formation may depend on the balance between the generating rate of H2 by a Mg alloy device degradation and its diffusion rate in the tissue. This balance can differ with implanting tissues, patients’ conditions, and animal species. It is difficult to predict the clinical results from the in vivo animal tests. In this study, we developed an in vitro model tissue system to observe the gas cavity formation behavior following the biocorrosion of a Mg alloy sample.

Free Research Field

生体材料学

Academic Significance and Societal Importance of the Research Achievements

Mg合金は、体液中の水と反応して容易に分解するため、生体吸収性金属材料としてステント・骨接合材等幅広い領域での医療応用が期待されている。これらのデバイスは、損傷部位の修復後には不要になるが、除去には再手術が必要であり、患者の肉体的・金銭的負担であった。Mg合金製デバイスの実用化は、このような負担の解消に有用である。本研究で開発した空孔形成挙動観察手法は、Mg合金の空孔形成挙動に影響を及ぼす生体内環境をin vitroにて再現可能であり、Mg合金製デバイスの適切な空孔形成リスク評価に適用可能であり、Mg合金製デバイス開発に貢献できる。