Encapsulation of Living Bifidobacteria in Ultrathin PVOH Electrospun Fibers

Abstract

This study shows the application of the electrospinning technique as a viable method for the encapsulation and stabilization of bifidobacterial strains. Poly(vinyl alcohol) (PVOH) was used as the encapsulating material because it is generally recognized as safe (GRAS), has a high oxygen barrier when dry, and is water soluble, hence allowing easy recovery of the bacteria for viability testing. A coaxial setup was used for encapsulation, and the so-obtained electrospun fibers had a mean diameter of ca. 150 nm. Incorporation of B. animalis Bb12 led to a decrease in melting point and crystallinity of the PVOH fibers and to an increase in the polymer glass transition temperature. The viability tests, carried out at three different temperatures (room temperature and 4 and -20 degrees C) showed that B. animalis Bb12 encapsulated within the electrospun PVOH fibers remained viable for 40 days at room temperature and for 130 days at refrigeration temperature, whereas a significant viability decrease was observed in both cases when bacteria were not encapsulated (p = 0.015 and p = 0.002, respectively).

Evaluation of a Nisin-Eluting Nanofiber Scaffold To Treat Staphylococcus aureus-Induced Skin Infections in Mice

“…Dheraprasart et al (30), however, reported a slight increase in fiber diameter when gelatin solutions were electrospun with nisin, but the increase was not statistically significant. Various molecules and living organisms have been electrospun into a variety of natural and synthetic fibers, as well as blends thereof, including antibiotics, growth factors, antimicrobial peptides, and silver nanoparticles, as well as living bacteria (31,(36)(37)(38)(39)(40)(41)(42). Addition of molecules to a solution before electrospinning may alter the conductivity, surface tension, and possibly the viscosity of the solution and thus influence the morphology and diameter of fibers formed during electrospinning.…”

Release and antibacterial activity of allyl isothiocyanate/β-cyclodextrin complex encapsulated in electrospun nanofibers

“…PVA as a nanofiber matrix was chosen since PVA is a suitable polymer type for food packaging applications shown in the literature by incorporating different molecules or bacteria into PVA films [30] and fibers [5,31] due to its high tensile strength, flexibility, high oxygen and barrier properties. Free AITC and inclusion complex of AITC with ␤-CD (AITC/␤-CD-IC) (Fig.…”

Nanofibrous solid dosage form of living bacteria prepared by electrospinning

“…Salalha et al [24] showed that Escherichia coli and Staphylococcus albus remained viable after electrospinning process and retained their viability in polyvinyl alcohol (PVA) matrix for at least 3 months when the bacteria-containing electrospun webs were stored at -20 and -55°C. Lopez-Rubio et al [25] incorporated living probiotic bacteria (B. animalis Bb12) into PVA nanofibers applying co-electrospinning and the cells remained viable after 40 days at room temperature and 130 days at 4 and -20°C under refrigeration. Henceforth they encapsulated B. animalis Bb12 into protein-and carbohydrate-based microcapsules using electrospraying [26].…”