Effect of vacuum plasma treatment duration on physicochemical, mechanical, and biocompatibility properties of bacteriophage-incorporated PVA/duck egg white nanofibers

Chronic wound infections caused by multidrug-resistant (MDR) Pseudomonas aeruginosa, pose a critical challenge in the clinical area, particularly for burn victims and immunocompromised patients where conventional antibiotic therapies continue to fail. This study reports the development of vacuum oxygen (O2) plasma treated electrospun nanofibers composed of polyvinyl alcohol (PVA), duck egg white (DEW), and P. aeruginosa-specific bacteriophage vB_PaP_DMTU_1 (10⁹ PFU mL⁻¹). By varying plasma exposure (1, 3, 5, and 10 min) at a fixed discharge power of 144 W (0.6 A), we precisely tuned surface chemistry to enhance wound dressing performance. Results demonstrate that short exposure durations (1–3 min) introduce oxygen-containing polar groups, significantly improving crystallinity (up to 46.7%), wettability (water contact angle from 99° to 49°), and total surface energy. These shifts resulted in a 72% increase in tensile strength, with a water vapor transmission rate (1981–2074 g m⁻² 24 h⁻¹) within the ideal clinical range for moist environment for wound healing. Crucially, these optimized conditions preserved phage viability achieving potent disruption of biofilm with large inhibition zones (41–50 mm) against MDR P. aeruginosa. In contrast, prolonged exposure (≥5 min) led to inactivation of phages, via capsid disruption. The nanofibers demonstrated superior biocompatibility, with minimal haemolytic activity (96% at 24 h). This study demonstrates that controlled vacuum O2 plasma treatment for 1–3 minutes produces mechanically robust, phage-active, and biocompatible PVA/DEW nanofibers offering an antibiotic-free strategy for combating P. aeruginosa in chronic and burn wound infections.