Dual functional antibacterial nanofiber membranes: Polyhexamethylene biguanide-integrated alginate-chitosan-dye...

Polyamide 56 (PA56) nanofiber membranes were functionalized with alginate (AG), chitosan (CS), reactive dyes (RG19, RR141), and poly(hexamethylene biguanide) (PHMB) to develop multifunctional antimicrobial membranes for single-use applications. The resulting membranes, PA56-AG-CS-RG19-PHMB and PA56-AG-CS-RR141-PHMB, achieved high antibacterial efficiencies of 97.12 % and 90.65 %, respectively, against Escherichia coli, demonstrating potent bacterial inhibition. The antimicrobial performance results from a synergistic dual mechanism. Chitosan disrupts bacterial adhesion and biofilm formation through electrostatic interactions, while PHMB compromises membrane integrity and interferes with intracellular processes. This combined action enhances bactericidal efficacy. The functionalization strategy also maintained excellent biocompatibility, with minimal cytotoxicity observed in L929 fibroblasts. Optimized concentrations of AG and CS were systematically evaluated to ensure balanced antibacterial performance and mechanical stability. These membranes, designed for single-use, exhibited significantly reduced antibacterial activity upon reuse, supporting their intended application. Overall, the integration of chemical and physical antimicrobial strategies within a nanofiber matrix presents a novel and effective approach. This strategy enables the development of next-generation materials suitable for real-world single-use biomedical applications, including wound dressings, food packaging, and protective textiles.