Effects of Interactions between ZnO Nanoparticles and Saccharides on Biological Responses

Zinc oxide (ZnO) nanoparticles (NPs) are widely used as a Zn supplement, because Zn plays a role in many cellular and immune functions but public concern about their potentially undesirable effects on the human body is growing. When NPs are added in food matrices, interactions between NPs and food components occur, which can affect biological systems. In this study, interactions between ZnO NPs and saccharides were investigated by measuring changes in hydrodynamic radius, zeta potential and solubility and by quantifying amounts of adsorbed saccharides on NPs; acacia honey, sugar mixtures (containing equivalent amounts of fructose, glucose, sucrose and maltose) and monosaccharide solutions were used as model compounds. Biological responses of NPs dispersed in different saccharides were also evaluated in human intestinal cells and rats in terms of cytotoxicity, cellular uptake, intestinal transport and oral absorption. The results demonstrate that the hydrodynamic radii and zeta potentials of NPs were highly affected by saccharides. In addition, trace nutrients influenced NP/saccharide interactions and interactive effects between saccharides on the interactions were found. NPs in all saccharides increased inhibition of cell proliferation and enhanced cellular uptake. Oral absorption of NPs was highly enhanced by 5% glucose, which is in-line with intestinal transport result. These findings show that ZnO NPs interact with saccharides and these interactions affects biological responses.