Development of a method for evaluating the antimicrobial properties of silver coatings.

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K18586
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 57040:Regenerative dentistry and dental engineering-related
• Research Institution: Aichi Gakuin University
• Principal Investigator: Hori Miki 愛知学院大学, 歯学部, 講師 (40804422)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 抗菌 / 銀 / 大腸菌 / 発光タンパク質 / 酸化ストレス

Outline of Final Research Achievements

The influence of silver contact on bacterial cells has been reported to induce oxidative stress and membrane damage. To investigate the chemical species responsible for oxidative stress on bacterial cells, we employed the NBT (nitroblue tetrazolium) method to detect the presence of superoxide ions and the precipitation method to determine the presence of hydrogen peroxide. Morphological observations were conducted using transmission electron microscopy to assess the effects. The results revealed the partial generation of superoxide ions and hydrogen peroxide.
Furthermore, in pursuit of establishing Escherichia coli, which continuously produces luminescent proteins, we introduced the picALuc gene into the BL21 strain. Initially, a high luminescence of 35,000 relative luminescence units (RLU) was transiently observed. However, with successive passages, the luminescence intensity exponentially decreased, and the establishment of a stable strain remained a topic for further investigation.

Free Research Field

歯科理工学

Academic Significance and Societal Importance of the Research Achievements

銀の抗菌効果についてはこれまで多くの報告があったものの、そのメカニズムについては近年ようやく解明されてきている。銀の抗菌効果を利用した歯科用機器も多く、特にインプラント材料については感染予防が成功の鍵となるためこの抗菌効果が期待されている。しかし、これまでに銀の抗菌効果を菌体のストレスレベルで評価できる方法がない。現時点での研究成果では実用には到達できておらず、菌体で安定的に発光タンパク質を生成する株の樹立が課題として残っている段階である。