Bacteria on nanotopographic metals

• Project/Area Number: 15H05547
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Structural/Functional materials
• Research Institution: Kyoto University
• Principal Investigator: Hakamada Masataka 京都大学, エネルギー科学研究科, 准教授 (30462849)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥24,570,000 (Direct Cost: ¥18,900,000、Indirect Cost: ¥5,670,000); Fiscal Year 2017: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000); Fiscal Year 2016: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000); Fiscal Year 2015: ¥18,980,000 (Direct Cost: ¥14,600,000、Indirect Cost: ¥4,380,000)
• Keywords: ナノポーラス / 金 / 抗菌 / 抗菌性 / ナノ材料

Outline of Final Research Achievements

The origin of high antibacterial properties of nanoporous gold is examined by comparison with flat gold. The tests of antibacterial properties against Escherichia coli (E. coli) and Staphylococcus epidermidis under various relative humidity suggest that the direct contact between nanoporous gold substrate and bacteria is necessary for killing bacteria. This is different from conventional antibacterial metals and alloys which emits diffusive species such as reactive oxygen species and metallic ions. The measurement of elastic modulus of E. coli cultured on gold substrates revealed that the E. coli on nanoporous gold was more stiffened than that on flat gold, which is contrary to the expectation. Atomic simulation and gene expression analyses suggested that the antibacterial mechanism of nanoporous gold is not merely due to the mechanical fracture of cell membrane but originated from complex and subtle conformational change in component such as peptidoglycan and ion channels.

Research Products

• [Journal Article] Antimicrobial mechanisms due to hyperpolarization induced by nanoporous Au (2018)
  • Author(s): Naoki Miyazawa, Masataka Hakamada and Mamoru Mabuchi
  • Journal Title: Scientific Reports Volume: 8 Issue: 1 Pages: 3870-3870
  • DOI: 10.1038/s41598-018-22261-5
  • NAID: 120006502569
  • Peer Reviewed / Open Access
• [Journal Article] Antibacterial activity of nanoporous gold against Escherichia coli and Staphylococcus epidermidis (2017)
  • Author(s): Masataka Hakamada, Seiji Taniguchi and Mamoru Mabuchi
  • Journal Title: Journal of Materials Research Volume: 印刷中
  • NAID: 120006596492
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] ナノ構造金属と細菌・細胞 (2017)
  • Author(s): 袴田昌高、馬渕守
  • Organizer: 日本金属学会2017年春期（第160回）講演大会
  • Place of Presentation: 八王子
  • Year and Date: 2017-03-16
• [Presentation] 抗菌性ナノポーラス金がイオンチャネルに及ぼす影響の分子動力学計算 (2017)
  • Author(s): 宮澤直己、袴田昌高、馬渕守
  • Organizer: 日本金属学会2017年秋期（第161回）講演大会
• [Presentation] 抗菌性ナノポーラス金と細菌細胞壁の相互作用の原子・電子シミュレーション (2016)
  • Author(s): 宮澤直己、袴田昌高、馬渕守
  • Organizer: 日本金属学会2016年秋期（第159回）講演大会
  • Place of Presentation: 豊中
  • Year and Date: 2016-09-23
• [Presentation] ナノポーラス金の抗菌性評価とメカニズム解明 (2016)
  • Author(s): 龍田星奈、袴田昌高、馬渕守
  • Organizer: 日本金属学会2016年秋期（第159回）講演大会
  • Place of Presentation: 豊中
  • Year and Date: 2016-09-23
• [Presentation] ナノポーラス金属と細菌・細胞 (2016)
  • Author(s): 袴田昌高、加藤直樹、龍田星奈、新宮淳平、馬渕守
  • Organizer: 日本金属学会2016年秋期（第159回）講演大会
  • Place of Presentation: 豊中
  • Year and Date: 2016-09-22
• [Presentation] ナノポーラス金の抗菌特性 (2015)
  • Author(s): 袴田昌高、谷口清二、馬渕守
  • Organizer: 日本金属学会2015年秋期（第157回）大会
  • Place of Presentation: 九州大学伊都キャンパス、福岡県博多市
  • Year and Date: 2015-09-18
• [Presentation] Antibacterial properties of nanoporous gold (2015)
  • Author(s): Masataka Hakamada and Mamoru Mabuchi
  • Organizer: 9th International Conference on Porous Metals and Metallic Foams
  • Place of Presentation: バルセロナ、スペイン
  • Year and Date: 2015-08-31
  • Int'l Joint Research