The Interactions Between ZnO Nanoparticles(NPs) And Nutrients Influence The Toxicity Of ZnO NPs On Cells

Zinc oxide nanoparticles(ZnO NPs)have been widely used in food,cosmetics,medicine,or many other fields due to its excellent chemical and physical properties.ZnO NPs can enter the human body through many routes including inhalation,skin penetration or ingestion,and then deposit in the alveoli and digestive tract or enter the blood circulation system to transport to various organs.Therefore,it is important to assess the potential health effects of ZnO NPs to ensure the safe use of them.However,most studies only shown the toxic effects of single NPs without considering the interaction of nutrients and NPs.This study explored the effects of ZnO NPs on cells in combination with the interaction between ZnO NPs and nutrients in order to provide a theoretical basis for the safe use of ZnO NPs.The main contents were summarized as below:1.The morphology,hydrodynamic size and zeta potential of ZnO NPs(NM110)were characterized by scanning electron microscopy(SEM)and malvern laser particle analyzer.Then,we chose human umbilical vein endothelial cells(HUVECs)as the cell model,and analyzed the cytotoxicity,oxidative stress and inflammation.The results indicated that the presence of ZnO NPs did not significantly affect the toxicity induced by PA or LPS.In addition,the accumulation of Zn ions after ZnO NP exposure was not significantly affected by the presence of sodium palmitate(PA)or lipopolysaccharide(LPS).We concluded that there was no interantion between ZnO NPs and PA or LPS on toxicity to HUVECs in vitro.2.The two kinds of ZnO NPs were characterized by using X-ray diffraction(XRD),raman spectroscopy,and transmission electron microscope(TEM).The interaction between ZnO NPs and PA was evaluated by using dynamic light scattering(DLS),UV-Vis spectra,and atomic absorption spectroscopy(AAS).Then,we chose Caco-2 cells as the cell model,and analyzed the cytotoxicity,oxidative stress and inflammation.The characterization results showed that the presence of PA significantly changed the UV-Vis absorption spectra,hydrodynamic size and Zeta potential of two different sizes of ZnO NPs indicating that there is an interaction between PA and ZnO NPs.AAS result showed that the interaction decreased the solubility of ZnO NPs in water and cell culture medium.In addition,presence of PA did not significantly affect all of these endpoints,and ANOVA analysis indicated no interaction between concentrations of ZnO NPs and the presence of PA.It is concluded that PA as a saturated fatty acid may influence the colloidal stability of ZnO NPs but did not affect the toxicity of ZnO NPs to Caco-2 cells.3.Atomic force microscope was employed to visualize the changes of topography of ZnO NPs to the incubation with bovine serum albumin(BSA)or palmitate(PA)-BSA.The colloidal aspects of ZnO NPs were analyzed by using dynamic light scattering(DLS)technology.Then,we chose THP-1 macrophages as the cell model,and analyzed the cytotoxicity,oxidative stress,inflammation,intracellular Zn ions and the expression of genes associated with ER stress and apoptosis after exposure of ZnO NPs±BSA/PA-BSA.AFM results showed the increase of NP heights after pre-incubation with BSA or PA-BSA,but PA-BSA more effectively altered the colloidal aspects of NPs.Pre-incubation with BSA alleciated ZnO NP induced cytotoxicity,and transmission electron microscopy confirmed fewer intrastructural changes.Pre-incubation with BSA and PA-BSA altered the pattern of intracellular Zn ions and ROS production.Co-exposure to PA-BSA and ZnO NPs induced a relatively higher ER stress marker DDIT3 and apoptosis gene CASP12 compared with the exposure.In summary,thes results showed that pre-incubation with BSA was more effective compared with PA-BSA to alleviate the toxicity of ZnO NPs to THP-1 macrophages.