Hybrid Electrospun Fibers for Rapid Delivery of Lactobacillus paragasseri K7 and Lactoferrin as Live Biotherapeutics and Postbiotics

K7 (LK7) and the bioactive glycoprotein lactoferrin (LF) with applications targeting vaginal health. Electrospinning was used to encapsulate LK7 and LF into poly-(ethylene oxide) (PEO)-based nanofibers supported on polypropylene fabric. Three formulationsPEO/LF, PEO/lactobacilli (LB) (with LK7), and PEO/LF/LBwere characterized for their physicochemical properties, fiber morphology (SEM), chemical composition (FTIR, XPS), and antioxidant activity (2,2'-azino-bis-(3-ethylbenz-thiazoline-6-sulfonic acid) (ABTS) assay). SEM analysis confirmed successful nanofiber formation, though LK7 remained on the fiber surface due to its size. FTIR and XPS analyses verified the incorporation of functional groups and elements associated with LF and LK7. The antioxidant assays showed that both LF and LK7 exhibited strong radical scavenging activity in formulations and it decreased slightly after electrospinning. Among the electrospun samples, the PEO/LF/LB formulation demonstrated the highest antioxidant potential. The viability and release studies revealed that 0.38-0.45% of LK7 survived during the electrospinning process and that the bacterial cells were released rapidly within 1 min of PBS exposure. Storage at 8 or 20 °C under 65% humidity reduced the viability (cfu) further, likely due to a transition to a viable but nonculturable (VBNC) state. Despite the low survival rates, the immediate release profile and antimicrobial potential of the materials support their suitability for short-term therapeutic applications such as vaginal tampons or wound dressings. This study highlights the potential of nozzle-free electrospinning for developing delivery systems for live biotherapeutics and postbiotics and suggests future work to optimize viability or expand into postbiotic applications.