Safety Assessment Of Sliver Nanoparticles In Food Packaging Materials On Human Epithelial Colorectal Adenocarcinoma (Caco-2) Cells

Sliver nanoparticles (Ag NPs) show outstanding antibacterial properties.Ag NPs are increasingly used in food, which raise the concern about their potentialtoxicity to human. Ag NPs may inhibit the segregation of chromosomes. genetoxicity, including DNA damage and chromosomal aberratins, has been observed inhuman glioblastoma cells treated with Ag NPs. However, the mechanism of Ag NPson human epithelial colorectal adenocarcinoma (Caco-2) cells in vitro and theirdetailed molecular mechanisms still remain unclear. In order to investigate thecytotoxicity of Ag NPs, human colon epithelial (Caco-2) cells were studied as thesubject cells，Zinc oxide nanoparticles（ZnO NPs） was used as the positive control.The cytotoxicity and oxidative damage of three kinds of sliver particles on Caco-2cells were explored. The main contents are as follows：（1）Scanning electron microscope and nano size analyzer were used tocharacterize the morphology and particle size distribution of three kinds of silverparticles.The results showed that the shape of three kinds of silver particles wasapproximately spherical. The size of one kind of silver particle was not the same,andthe particle size distribution of silver particles approached normal distribution. Theiraverage particle size was35.48nm,76.29nm and265.2nm, respectively. Accordingto the definition of nanomaterials, the first two silver particles was nano silver, thethird kind of silver particles was micron silver.（2） In order to investigate the cytotoxicity of Ag NPs（35.48nm）, humancolon epithelial (Caco-2) cells were studied as the subject cells. ZnO NPs （26.21nm）was used as the positive control. The cells without nanomaterials were regardedas the blank control. AO/EB double staining and WST-1method was used toinvestigate the preliminary cytotoxicity. Using the method of oxidative stressdetection, the release of ROS、SOD、GSH was measured to explore the oxidativedamage of Caco-2cells induced by Ag NPs. The results showed that Ag NPs（35.48nm）at the concentration of0-50μg/mL had no significant effect on the Caco-2cellsactivity. Caco-2cells were not damaged for oxidative stress. The cytotoxicity of Ag NPs at the concentration of75μg/mL on and100μg/mL have time-depended anddose-depended toxicity. And Caco-2cells were damaged for oxidative stress.（3） In order to investigate the cytotoxicity of Ag NPs（76.29nm）, humancolon epithelial (Caco-2) cells were studied as the subject cells. ZnO NPs （90.81nm）was used as the positive control. The cells without nanomaterials were regardedas the blank control. AO/EB double staining and CCK-8method was used toinvestigate the preliminary cytotoxicity. Using the method of oxidative stressdetection, the release of ROS、SOD、GSH was used to explore the oxidative damageof Caco-2cells induced by Ag NPs. The results showed that Ag NPs (0-200μg/mL;76.29nm) had no significant effect on the Caco-2cells activity. Caco-2cells werenot damaged for oxidative stress, but the cells antioxidant capacity significantlyenhanced. With the addition of nano-silver concentration, cellular antioxidantweakened.（4） In order to investigate the food safety of Ag NPs, the cytotoxicity ofsliver particles（265.2nm）was studied as the supplement and control. Human colonepithelial (Caco-2) cells were studied as the subject cells. The cells without sliverparticles were regarded as the blank control. AO/EB double staining and MTTmethod was used to investigate the preliminary cytotoxicity. Using the method ofoxidative stress detection, the release of ROS、SOD、GSH was used to explore theoxidative damage of Caco-2cells induced by Ag NPs. The results showed that sliverparticles（0-200μg/mL;265.2nm）had no significant effect on the activity of Caco-2cells. A sliver particles (0-50μg/mL) had no damaged for oxidative stress. at theconcentration of75μg/mL and100μg/mL sliver particles, Caco-2cells weredamaged for oxidative stress. And the redox equilibrium in Caco-2cells was broken.