Ginseng ameliorates pulmonary toxicity induced by silicon dioxide nanoparticles in rats

Objective:To investigate the protective and therapeutic role of ginseng against silicon dioxide nanoparticles(SiO2NPs)-induced toxicity in the lungs.Methods:Sixty male rats were divided into five groups(n=12/group);group 1 was used as a control,group 2 received ginseng,group 3 was treated with SiO2NPs,and group 4 was pretreated with ginseng one week before SiO2NPs,while group 5 was given SiO2NPs one week before supplementation with ginseng.Animals were treated with both ginseng and SiO2NPs orally for five weeks.Real-time PCR was used to measure gene expression.Besides,DNA damage and cell cycle changes were determined by comet assay and flow cytometry,respectively.Histological study was also done to assess the effect of ginseng on SiO2NPs-induced toxicity.Results:SiO2NPs increased lipid peroxidation and decreased the activities of antioxidant enzymes.SiO2NPs induced apoptosis in lung tissues as revealed by upregulation of Bax and caspase 3 and downregulation of Bcl-2 as well as the induction of DNA damage.SiO2NPs also caused inflammation as indicated by upregulation of the inflammation-related genes[interleukin 1 beta(IL-1β),tumor necrosis factor-alpha(TNF-α),nuclear factor kappa B(NF-κB),cyclooxygenase 2(COX2),and transforming growth factor-beta 1(TGFβ1)]as well as cell cycle arrest in the G0/G1 phase of lung cells.Moreover,histopathological examination proved the biochemical and molecular perturbations that occurred due to SiO2NPs toxicity.However,ginseng alleviated SiO2NPs-induced toxicity in rat lung.Conclusions:Ginseng has a potent preventive and therapeutic effect and could be used in the treatment of SiO2NPs-induced pulmonary toxicity.

Toxicity of silicon dioxide nanoparticles with varying sizes on the cornea and protein corona as a strategy for therapy

The human cornea is exposed directly to particulate matter （PM） in polluted air. This exposure can cause eye discomfort and corneal injury. Ultrafine PM （diameter ~100 nm） is thought to be particularly harmful to health, but there is limited research investigating its toxicity to the eye. In this study, we evaluated toxiciW differences among 30-, 40-, 100- and 150-nm silicon dioxide nanoparticles （Si02 NPs） on the cornea. A 24-hour in vitro exposure of primary human corneal epithelial cells （hCECs） to ultrafine （30 and 40 nm） SiO2 NPs produced toxicity, as evidenced by cell membrane damage, reduced cell viability, increased cell death and mitochondrial dysfunction. In vivo exposure to the same nanoparticles produced observable corneal injury. These effects were more severe with ultrafine than with fine （100 and 150 nm） Si02 NPs. Common antioxidant compounds, e.g., glutathione, did not protect the cornea from SiO2 NP-induced damage. However, foetal bovine serum （FBS） did significantly reduce toxicity, likely by forming a protective protein corona around the nanoparticles. This finding suggests that FBS （or its derivatives） may be a useful clinical therapy for corneal toxicity caused by ultrafine particulates.

Synthesis and characterization of Fe_3O_4@SiO_2 magnetic composite nanoparticles by a one-pot process

Fe3O4@SiO2 core–shell composite nanoparticles were successfully prepared by a one-pot process. Tetraethyl-orthosilicate was used as a surfactant to synthesize Fe3O4@SiO2 core–shell structures from prepared Fe3O4 nanoparticles. The properties of the Fe3O4 and Fe3O4@SiO2 composite nanoparticles were studied by X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy, and Fourier transform infrared spectroscopy. The prepared Fe3O4 particles were approximately 12 nm in size, and the thickness of the SiO2 coating was approximately 4 nm. The magnetic properties were studied by vibrating sample magnetometry. The results show that the maximum saturation magnetization of the Fe3O4@SiO2 powder（34.85 A·m^2·kg^–1） was markedly lower than that of the Fe3O4 powder（79.55 A·m^2·kg^–1）, which demonstrates that Fe3O4 was successfully wrapped by SiO2. The Fe3O4@SiO2 composite nanoparticles have broad prospects in biomedical applications; thus, our next study will apply them in magnetic resonance imaging.