Decoration of Nano-Spikes on Polymeric Surfaces with Quaternized <i>N-</i> 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 <i>N</i>-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 <i>N</i>-chloramine. The resulting hybrid surface, denoted as <i>P</i>_nCl, was evaluated against <i>Escherichia coli</i> and <i>Methicillin-resistant</i> <i>Staphylococcus aureus</i> (MRSA). Compared to the control surfaces <i>P</i>_n and <i>P</i>_Cl, <i>P</i>_nCl demonstrated superior antibacterial activity, achieving a 100% reduction in <i>E. coli</i> 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 (<i>N</i>-chloramine) with biocidal nanotopography on a single surface, offering a promising avenue for the development of advanced antimicrobial materials.