Recombinant antimicrobial mussel adhesive protein-integrated PVA nanofibers with stable and long-lasting antibacterial activity

Conventional antibacterial systems often suffer from limited durability due to the leaching of active components and concerns associated with the inorganic antibacterial agents. Hence, there is growing interest in developing advanced antibacterial platforms that can integrate surface functionality, non-antibiotic mechanisms, and the long-term stability. Herein, we report recombinant antimicrobial mussel adhesive protein (AMAP) was incorporated into a poly(vinyl alcohol) (PVA) matrix, and electrospun to form nanofiber webs with an average diameter of ∼ 330 nm. The as-spun nanofibers were subsequently rendered water-insoluble via thermal treatment, followed by systematic characterization of their structural evolution, surface properties, wettability, and their antibacterial performance. The AMAP-incorporated nanofibers exhibited significantly enhanced structural integrity compared to pristine PVA, maintaining their morphology even after prolonged water immersion treatment. The surface wettability underwent a pronounced transition from moderately hydrophobic (71.7°) to highly hydrophilic (16.2°) upon thermal treatment. This transition also contributed to a bacterial reduction rate of 96.0% against S. aureus ( S. aureus ), and 92.9% against Escherichia coli ( E. coli ), while retaining 91.3% and 87.5% antibacterial activity against S. aureus and E. coli , respectively, after 30 days of storage under the ambient conditions. These results demonstrate that the AMAP incorporation, combined with thermal processing, enables simultaneous structural stabilization and surface functionalization through amphiphilic intermolecular interactions with the PVA matrix, providing an effective strategy for sustained antibacterial performance without antibiotics or inorganic agents.