Zinc oxide nanoparticles encapsulated in polysaccharides alginate/gum acacia and iron oxide nanomatrices show enhanced biocompatibility and permeability to intestinal barrier

Zinc oxide is often used as a dietary supplement because zinc is an important dietary and trace element that contributes immensely to the body's functions. Iron and zinc deficiencies are the most common in the world. They often combine with phytate, which interferes with iron and zinc absorption. Nanoscale moieties improve the bioavailability of zinc and iron but also pose an unknown threat to human health. To render them biocompatible, we encapsulated ZnONPs in alginate/gum-acacia (SAGA ZnONPs) hydrocolloids and further conjugated them with iron oxide. The nanomatrices are stable and less than 100 nm in size as determined by transmission electron microscopy and biocompatible with human intestinal Caco-2 cells. Fe/SAGA ZnONPs release higher zinc at acidic pH (stomach) than in intestinal pH. We determined the effect of alginate/gum /iron oxide ZnONPs matrices on various digestive processes using the intestinal cells (Caco-2) on permeable support. Uptake efficiencies of Zn/Fe using Fe/SAGA ZnONPs are higher than bare ZnONPs. Our results demonstrated that alginate and gum acacia are promising polysaccharides for ZnONPs to protect them against harsh digestive milieu. Further conjugation with iron oxide is shown to be an efficient delivery system.