Clarification of the biodegradation of carbon nanotubes for safe use by design

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H02742
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Nanomaterials chemistry
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Zhang Minfang 国立研究開発法人産業技術総合研究所, 材料・化学領域, 主任研究員 (60518330)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: カーボンナノチューブ / カーボンナノ材料 / 生分解 / 免疫細胞 / 動物実験

Outline of Final Research Achievements

The great concern about the risk of carbon nanotubes (CNTs) for practical application is related to their extremely stable structures, which are difficult to be biodegraded. Recently, it has been reported that CNTs may be degraded by enzymes and immune cells, and the debate on the stability of CNTs in living body is rapidly increasing. However, many detail issues are still remained especially no quantitative studies were performed. In this study, a method for measuring the amount of CNT in cells and living tissues by using near infrared absorption technique have been developed, and used to quantitatively evaluate the biodegradation of CNT in vitro and in vivo. In addition, the size dependence of the biodegradability of CNTs was clarified. CNTs with small diameters were more easily degraded than those with larger diameters.

Free Research Field

カーボンナノ材料

Academic Significance and Societal Importance of the Research Achievements

CNT産業の創出に伴って、CNTが環境へ暴露し、動物や人体に吸収されて免疫組織に蓄積する可能性があり、健康への有害な影響への懸念がある。本研究では、CNTの近赤外光吸収特性を活かして、細胞内や生体組織内のCNT定量測定方法を開発した。この技術は、今研究のCNT生分解性の解明に利用できるだけではなく、CNTの安全性評価やCNTのナノメディシンへの応用研究にも役に立つ。また、CNTの生分解特性のサイズ依存性の解明は、CNTの構造特性からCNTの生分解性の予測が可能になり、特定の用途に適したCNTのタイプの選定ができ、安全性を確保したCNTの実用化に貢献される。