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Bacterial adhesion and colonization on stainless steel (SSL) based surgical instruments, hospital equipment, orthopedic implants, water purification and food processing units are a major problem. Imparting rechargeable antibacterial properties to SSL offers the prospect of a reusable and clean surface. In this study, the SSL surface was functionalized with a hydantoin-based antibacterial polymer that prevents bacterial adhesion and colonization. A new hydantoin monomer with three halogen binding sites, (Z)-N-((4-(2,5-dioxoimidazolidin-4-ylidene)methyl)phenyl)methacrylamide (DMPM), was synthesized, characterized and copolymerized with a commercially available 3-(methacryloyloxy)propyltrimethoxysilane monomer to develop the antibacterial polymer. The SSL surface was treated with piranha solution and the copolymer was covalently immobilized on the surface. The modified surface was examined for its antibacterial and anti-biofilm activity. The modified surface exhibited total kill (6 log reduction) of bacteria such as S. aureus and E. coli in 10 and 12 min respectively. The anti-biofilm activity of the modified surface was evaluated using a combination of fluorescence-based metabolic activity and scanning electron microscopy imaging suggested the comprehensive damage of S. aureus and E. coli biofilm architecture.

N-Halamine-based antibacterial polymers play a significant role in controlling microbe-associated surface contamination. Hydantoin-containing polymers are usually synthesized by tethering polymerizable moieties to 5,5′-dialkyl hydantoin. However, such approaches sacrifice the imide hydrogen in the molecule, thereby restricting the halogen capture only to the amide nitrogen. In this paper, we report the synthesis of a novel polymerizable hydantoin monomer containing one more amide group in addition to the amide and imide groups already present in hydantoin to maximize the halogen capture and hence its antibacterial activity. The synthesized monomer was copolymerized with methyl methacrylate (MMA) and styrene. The monomer and its copolymers were characterized using 1H and 13C NMR, HRMS, FTIR, XPS, TGA, DTA and GPC. The oxidative chlorine content of the copolymers ranged from 0.9% to 1.21%. The polymers were spin coated onto glass surfaces to study their antimicrobial potential. The polymer-coated glass surfaces exposed to both Gram positive S. aureus and Gram negative E. coli bacteria using standard protocols showed total kill of the bacteria within 15 minutes of exposure. These new hydantoin polymers showed highly superior antibacterial activities compared to many such polymers reported so far in the literature.