Toxicological Study Of Food Grade Nano-sized Iron Oxide On Female Mice

Nanomaterial additives can not only improve the taste and texture of food as well as their nutritional value,but also prolong the shelf life of food during the food processing.Therefore,the opportunities that people are involved in the exposure of additive nanomaterials have been increased due to the great potential of nanomaterials in the food additive industry and their positive roles in producing healthier and safer food.However,mountains of studies have shown that the unique properties of nanomaterials,such as surface modification,nano size and so on,will have some negative biological effects on human health and ecological environment.If the exposed nanomaterial additives do not decompose,metabolize or excrete successfully after digestion in human body,these nanomaterials may be transported by cells to organs such as spleen,liver and bone marrow and accumulated in these organs or finally further delivered to the organs like brain and kidneys.Therefore,it is of importance and urgency to establish the analysis,characterization and safety evaluation of nanomaterials in consumer goods,especially in foods that can be directly absorbed by the human body.In this paper,we firstly separated the nanomaterial additives such as iron oxide,titanium dioxide and silica particles in Yukasha chocolate beans and snow-flavored milk shellfish by solvent extraction.These separated nanomaterials were then characterized by electron microscope,Energy Disperse Spectroscopy(EDS)and X-ray Diffraction(XRD).The results showed that 20-100 nm of agglomerated iron oxide and titanium dioxide nanoparticles with irregular spherical shapes were involved in Lokasha chocolate bean,in which the iron oxide nanoparticles showed poor enrichment.While the original milk shellfish contained 100-300 nm of agglomerated silica nanoparticles.Based on these results,we tried to focus on the toxicologic study of food-grade iron oxide.The particle size,morphology,hydrated particle size,agglomeration state,chemical composition,surface potential and crystal form of food grade iron oxide authorized by European Commission were first characterized.Then food grade iron oxide was used as the model nanomaterial to evaluate its in vivo toxicity in female mice.We found that although iron oxide with food grade had no significant effects on the body weight,food intake and blood routine of mice,they may cause serious damage to the gastrointestinal structure of mice,especially duodenum,jejunum and ileum.For reproductive toxicity,the female mice treated with high-dose iron oxide exhibited shorter estrous cycle and decreased pregnancy rate,indicating that iron oxide with food-grade affected the mating and pregnancy of female mice,but had no significant effect on the growth and development of offspring.