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

## TL;DR

This paper explores using electrospun fibers to deliver a probiotic and lactoferrin for vaginal health, showing rapid release and antioxidant properties.

## Contribution

The study introduces a nozzle-free electrospinning method for encapsulating live bacteria and bioactive compounds into nanofibers for therapeutic applications.

## Key findings

- PEO/LF/LB formulation showed the highest antioxidant activity among tested samples.
- LK7 bacteria were rapidly released within 1 minute of PBS exposure.
- Storage conditions reduced bacterial viability, likely causing a viable but nonculturable state.

## Abstract

This study explores the development of electrospun nanofibrous
materials as delivery systems for the probiotic strain Lactobacillus
paragasseri 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.