Electrospun Zein/hydroxypropyl methylcellulose/silver citrate nanofibres with enhanced thermal and morphological stability for wound healing.

Wound dressing is a critical in wound healing, yet natural electrospun nanofibres often lack thermal and morphological stability, limiting clinical utility. To address this, Zein nanofibrous mats with silver citrate nanorods (AgCit) were fabricated by electrospinning, crosslinked with citric acid (catalysed by sodium hypophosphite), and reinforced with hydroxypropyl methylcellulose (HPMC). FE-SEM revealed bead-free fibres at 5 mM AgCit, 40 wt% Zein, and 0.5 wt% HPMC, with an average diameter of 930 ± 5.5 nm. Morphological stability was achieved by HPMC reinforcement and AgCit, which prevent fibre collapse under aqueous immersion, while crosslinking was insufficient. Thermal stability was enhanced by citrate-Zein interactions and compact chain packing induced by HPMC, as confirmed by DSC (Tg1 above 100 °C) and TGA (reduced degradation rates). These strategies provided dual advantages: resilience under physiological conditions and improved durability during processing. Cell assays demonstrated cytocompatibility, proliferation, and migration, with AgCit supporting wound closure. Time-kill curves showed a 90.67 ± 0.49% and 92 ± 0.96% of antibacterial efficiency against E. coli and S. aureus, respectively within 9 h. The mechanism involves hydrogen bonding and chain entanglement between Zein and HPMC, reinforced by citrate crosslinking, while AgCit contributes antibacterial activity and HPMC provides antioxidant effect.