Cytotoxicity of selected metal oxide nanoparticles（MNPs）（ZnO,CuO,Co 3 O 4 and TiO 2）was investigated in Escherichia coli both under light and dark conditions.Cytotoxicity experiments were conducted with spread pla...Cytotoxicity of selected metal oxide nanoparticles（MNPs）（ZnO,CuO,Co 3 O 4 and TiO 2）was investigated in Escherichia coli both under light and dark conditions.Cytotoxicity experiments were conducted with spread plate counting and the LC 50 values were calculated.We determined the mechanism of toxicity via measurements of oxidative stress,reduced glutathione,lipid peroxidation,and metal ions.The overall ranking of the LC 50 values was in the order of ZnO 〈 CuO 〈 Co 3 O 4 〈 TiO 2 under dark condition and ZnO 〈 CuO 〈 TiO 2 〈 Co 3 O 4 under light condition.ZnO MNPs were the most toxic among the tested nanoparticles.Our results indicate depletion of reduced glutathione level and elevation of malondialdehyde level correlated with the increase in oxidative stress.Released metal ions were found to have partial effect on the toxicity of MNPs to E.coli.In summary,the dynamic interactions of multiple mechanisms lead to the toxicity of the tested MNPs to E.coli.展开更多
Quantum dots （QD） nanoparticles have been widely used in biomedical and electronics fields, because of their novel optical properties. Consequently it confers enormous potential for human exposure and environmental ...Quantum dots （QD） nanoparticles have been widely used in biomedical and electronics fields, because of their novel optical properties. Consequently it confers enormous potential for human exposure and environmental release. To increase the biocompatibility of QDs, a variety of surface coatings or functional groups are added to increase their bioactivity and water solubility. Human adult low calcium high temperature （HaCaT） cells are the epithelial cells derived from adult human skin that exhibits normal differentiation capacity and a DNA fingerprint pattern that is unaffected by long-term cultivation, transformation, or the presence of multiple chromosomal alternations. Human keratinocytes, HaCaT cells were used to systematically evaluate the cytotoxicity of biocompatible QD made of CdSe metal core and ZnS shell with three different coatings and at three different wavelengths （530, 580 and 620 nm）. In terms of half- maximal inhibitory concentration, QSA-QDs with amine-polyethyleneglycol coating and QSH-QDs with amphiphilic polymer coating were not cytotoxic, while QEI-QDs with polyethylenimine coating were highly toxic to the HaCaT cells in comparison to a reference CulnS2/ZnS. QEI-QDs led to significant increase in reactive oxygen species, decrease in mitochondrial membrane potential and DNA damage in HaCaT cells. The mechanisms of toxicity of QEI-530 and QEI-580 can be attributed to the combination of intracellular reactive oxygen species production and loss of MMP. The QDs toxicity can be attributed to the polyethylemimine surface coating which was highly toxic to cells in comparison with amine-polyethyleneglycol, but not due to the release of cadmium ions.展开更多
基金NSF-SBIR grant # IIP-0823040NSF-CREST program with grant # HRD-0833178Strengthening the Environmental Science Ph.D program in instruction,grant # P031B090210-11
文摘Cytotoxicity of selected metal oxide nanoparticles（MNPs）（ZnO,CuO,Co 3 O 4 and TiO 2）was investigated in Escherichia coli both under light and dark conditions.Cytotoxicity experiments were conducted with spread plate counting and the LC 50 values were calculated.We determined the mechanism of toxicity via measurements of oxidative stress,reduced glutathione,lipid peroxidation,and metal ions.The overall ranking of the LC 50 values was in the order of ZnO 〈 CuO 〈 Co 3 O 4 〈 TiO 2 under dark condition and ZnO 〈 CuO 〈 TiO 2 〈 Co 3 O 4 under light condition.ZnO MNPs were the most toxic among the tested nanoparticles.Our results indicate depletion of reduced glutathione level and elevation of malondialdehyde level correlated with the increase in oxidative stress.Released metal ions were found to have partial effect on the toxicity of MNPs to E.coli.In summary,the dynamic interactions of multiple mechanisms lead to the toxicity of the tested MNPs to E.coli.
基金supported by NSF-SBIR grant #IIP-0823040 and NSF-CREST program with grant #HRD-0833178
文摘Quantum dots （QD） nanoparticles have been widely used in biomedical and electronics fields, because of their novel optical properties. Consequently it confers enormous potential for human exposure and environmental release. To increase the biocompatibility of QDs, a variety of surface coatings or functional groups are added to increase their bioactivity and water solubility. Human adult low calcium high temperature （HaCaT） cells are the epithelial cells derived from adult human skin that exhibits normal differentiation capacity and a DNA fingerprint pattern that is unaffected by long-term cultivation, transformation, or the presence of multiple chromosomal alternations. Human keratinocytes, HaCaT cells were used to systematically evaluate the cytotoxicity of biocompatible QD made of CdSe metal core and ZnS shell with three different coatings and at three different wavelengths （530, 580 and 620 nm）. In terms of half- maximal inhibitory concentration, QSA-QDs with amine-polyethyleneglycol coating and QSH-QDs with amphiphilic polymer coating were not cytotoxic, while QEI-QDs with polyethylenimine coating were highly toxic to the HaCaT cells in comparison to a reference CulnS2/ZnS. QEI-QDs led to significant increase in reactive oxygen species, decrease in mitochondrial membrane potential and DNA damage in HaCaT cells. The mechanisms of toxicity of QEI-530 and QEI-580 can be attributed to the combination of intracellular reactive oxygen species production and loss of MMP. The QDs toxicity can be attributed to the polyethylemimine surface coating which was highly toxic to cells in comparison with amine-polyethyleneglycol, but not due to the release of cadmium ions.
