Decoration of Nano-Spikes on Polymeric Surfaces with Quaternized N-Chloramines for Enhanced Antibacterial Activity

Contact-active antibacterial surfaces are increasingly recognized as effective strategies for mitigating bacteria-related infections. Traditionally, physical contact-active antibacterial surfaces have been employed in biomedical implants, while chemical contact-active antibacterial surfaces are more commonly applied to hospital equipment, high-touch surfaces, and the food industry. In this study, we report the design of an innovative polymeric surface that integrates contact-active chemical and physical antibacterial mechanisms within a single platform. Specifically, we combined a chemical biocide─contact-active quaternized N-chloramine─with a nanotopographical killing mechanism inspired by the natural antibacterial properties of insect wings. Our fabrication process successfully replicates the nanoscale features of these natural surfaces on a polymer, incorporating nano spikes functionalized with an alkynyl handle. This handle facilitates a click chemistry reaction with the antibacterial agent N-chloramine. The resulting hybrid surface, denoted as P_nCl, was evaluated against Escherichia coli and Methicillin-resistant Staphylococcus aureus (MRSA). Compared to the control surfaces P_n and P_Cl, P_nCl demonstrated superior antibacterial activity, achieving a 100% reduction in E. coli populations within 15 min of contact and complete eradication of MRSA within 60 min. This study underscores the potential of combining a nonleaching, contact-active chemical biocide (N-chloramine) with biocidal nanotopography on a single surface, offering a promising avenue for the development of advanced antimicrobial materials.