Electrosprayed microparticles from inulin and poly(vinyl) alcohol for colon targeted delivery of prebiotics

Recent studies have highlighted the prebiotic effect of inulin through the selective promotion of colon-residing bacteria, modulation of the composition of the gut microbiome, and consequent generation of beneficial effects on gastrointestinal inflammation, diabetes, and cancer. However, as a water-soluble polysaccharide, the prebiotic effect of inulin is limited by low delivery efficiency and short retention time within the colon. In this study, inulin microparticles (MPs) were produced by the electrospray method, and their material properties and bioavailability were evaluated. Inulin was electrosprayed with poly(vinyl) alcohol (PVA) (MW = 89,000–98,000 g/mol) to improve its processability and mucoadhesive properties. MPs produced at PVA:Inulin mass ratio 1:3 were of diameter 0.42 ± 0.46 μm. FTIR and confocal laser scanning microscopy confirmed the presence and colocalization of the PVA and inulin in the particles. MP suspensions exhibited a time dependent viscoelastic rheological response that trended with time toward the response of the inulin suspension. Additionally, MP suspensions exhibited greater viscosity and shear thinning behavior than their individual components and two-component mixtures. The gut retention of inulin in mice was prolonged when delivered in these MP suspensions relative to inulin suspensions and PVA-inulin two-component mixtures. The increased retention is hypothesized to be a result of the effect of PVA on rheological and mucoadhesive properties. The increased retention of inulin leads to improved availability of inulin for gut microbiota which can support applications in drug delivery and foods.