Contact-Killing Antibacterial Polystyrene Polymerized Using a Quaternized Cationic Initiator
Akiko Jitsuhiro, Tomoki Maeda, Akiko Ogawa, Sayuri Yamada, Yuki Konoeda, Hiroki Maruyama, Fuyuaki Endo, Midori Kitagawa, Keishi Tanimoto, Atsushi Hotta, Toshikazu Tsuji
Abstract
High Resolution Image Download MS PowerPoint Slide Contact-killing antibacterial materials are attracting attention owing to their ability for sustained antibacterial activity. However, contact-killing antibacterial polystyrene (PS) has not been extensively studied because its chemically stable structure impedes chemical modification. In this study, we developed an antibacterial PS sheet with a contact-killing surface using PS synthesized from 2,2′-azobis-[2-(1,3-dimethyl-4,5-dihydro-1 H -imidazol-3-ium-2-yl)]propane triflate (ADIP) as a radical initiator with cationic moieties. The PS sheet synthesized with ADIP (ADIP-PS) exhibited antibacterial activity in contrast to PS synthesized with other azo radical initiators. Surface ζ-potential measurements revealed that only ADIP-PS had a cationic surface, which contributed to its contact-killing antibacterial activity. The ADIP-PS sheets also exhibited antibacterial activity after washing. In contrast, PS sheets containing silver, a typical leachable antibacterial agent, lost all antibacterial activity after the same washing treatment. The antibacterial ADIP-PS sheet demonstrated strong broad-spectrum activity against both Gram-positive and Gram-negative bacteria, including drug-resistant bacteria. Cytotoxicity tests using L929 cells showed that the ADIP-PS sheets were noncytotoxic. This contact-killing antibacterial PS synthesized with ADIP thus demonstrated good prospects as an easily producible antimicrobial material.