Antibiofilm Coatings via VAT Polymerization: Fabrication and Biofilm Inhibition Assessment

Tuesday, October 21, 2025: 1:10 PM
Prof. Hideyuki Kanematsu , BEL Inc., Sakai, Osaka, Japan, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
Ms. Sakura Tsutsui , Suzuka National College of Technology, Suzuka, Japan
Ms. Nonno Nishizuka , Suzuka National College of Technology, Suzuka, Japan
Prof. Hidekazu Miura , Suzuka University of Medical Science, Suzuka, Japan
Prof. Akiko Ogawa , National Institute of Technology, Suzuka College, Suzuka, Japan
Prof. Takeshi Kogo , Suzuka National College of Technology, Suzuka, Japan
Prof. Nobumitsu Hirai , National Institute of Technology, Suzuka College, Suzuka, Japan
Prof. Tsunemasa Saiki , University of Fukuchiyama, Fukuchiyama, Kyoto, Japan
Dr. Akira Otsu , Hyogo Prefectural Institute of Technology, Kobe, Japan
Dr. Akihiro Hirayama , Hyogo Prefectural Institute of Technology, Kobe, Japan
Prof. Risa Kawai , Nara Women's University, Nara, Japan
Prof. Katsuhiko Tsunashima , National Institute of Technology, Wakayama College, Gobo, Japan
Dr. Michiko Yoshitake , BEL Inc., Sakai, Osaka, Japan
Prof. Takayoshi Nakano , Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
Biofilms are structured microbial communities of bacteria and extracellular polymeric substances (EPS) forming on material surfaces in aqueous environments. These slime-like layers can lead to material degradation, equipment failure, and hygiene concerns in industrial and medical applications. As bacterial adhesion and biofilm formation are often closely linked to the surface properties of materials, surface engineering strategies have emerged as a promising approach to biofilm suppression.

In this study, light-curable acrylic resins were modified with antimicrobial additives and fabricated into surface coatings using VAT polymerization—a method known for its high resolution and precision. Two biofilm-inhibiting agents were investigated: silver particles and quaternary ammonium-based ionic liquids. Both are known to exhibit antimicrobial activity via different mechanisms. Silver ions interact with bacterial membranes, disrupting metabolic functions, while ionic liquids impair membrane integrity and are thought to alter microbial adhesion behavior.

Biofilm inhibition was evaluated using crystal violet staining and optical density measurements. Raman spectroscopy was also employed to explore the structural behavior of the composite materials. Notably, coatings containing ionic liquids demonstrated enhanced antimicrobial performance and improved surface compatibility, suggesting that these additives contribute positively to biofilm resistance. Although the exact dispersion mechanisms within the resin matrix remain challenging to observe directly, spectroscopic variations suggest a meaningful relationship between molecular-level distribution and biofilm suppression efficiency. These findings highlight the potential of combining antimicrobial agents with VAT polymerization techniques to develop advanced, hygienic surface coatings. The results provide insight into designing next-generation functional materials for biofilm control in critical healthcare and food processing environments.

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