Significant cell toxicity was only evident for the 10 nm citrate coated and the 10 nm PVP coated AgNPs after 24 h for their highest doses. No significant alterations of the mitochondrial activity of the BEAS 2B cells were observed for any of the lower doses or the other AgNPs. The interference of the AgNPs with the AB assay was tested in an acellular system and found to be non significant. http://www.selleckchem.com/products/mek162.html The LDH assay is a cytotoxicity assay that measures membrane damage by quantifying the amount Inhibitors,Modulators,Libraries of LDH released from the cytoplasm. BEAS 2B cells were exposed to AgNPs for 4 and 24 h. No significant toxicity was observed after 4 h for any of the AgNPs. However, significant tox icity was observed after 24 h for the 10 Inhibitors,Modulators,Libraries nm citrate coated and the 10 nm PVP coated AgNPs at the highest dose.

None of the lar ger sized AgNPs altered the cell viability. Some AgNPs have been shown to interact with the LDH Inhibitors,Modulators,Libraries assay via enzyme inhibition or binding. To investigate this issue we incubated AgNPs with cell ly sates and detected the LDH activity after 0, 4 and 24 h. The reduction in enzyme activity was most pronounced for the 10 nm AgNPs, especially for the citrate coated particles, and occurred in a Inhibitors,Modulators,Libraries time and dose dependent manner. The enzyme inhibition is likely correlated with the Ag release since Ag ions have been shown to inhibit the catalytic activity of LDH enzyme. Therefore, LDH results should be interpreted with caution and the possibility of false nega tive results be considered, especially for particles with low stability that release Ag ions.

AgNPs induce DNA damage in human lung cells The potential of AgNPs to induce DNA damage was in vestigated with two different assays alkaline comet assay that gives indication on the overall Inhibitors,Modulators,Libraries DNA damage and H2AX foci for mation, which is mainly a marker of DNA double strand breaks. The alkaline comet assay was used to determine the DNA damage associated with exposure to non cytotoxic concentrations of AgNPs in BEAS 2B cells. No significant increase in the percentage of DNA in the comet tail was observed after 4 h exposure to any of the AgNPs. However, a statistically significant increase in overall DNA damage was observed after 24 h for all AgNPs, independent of size and coating. The H2AX foci formation was assessed by immuno cytochemistry in BEAS 2B cells under the same condi tions as for the comet assay, i. e.

4 and 24 h exposure to 10 ugmL AgNPs. All fluorescent stainings were negative No cellular ROS increase upon exposure to AgNPs The kinetics of intracellular Oligomycin A purchase ROS formation after expos ure of BEAS 2B cells to AgNPs was measured using the dichlorodihydrofluorescein diacetate assay. The DCFH DA probe can detect cytosolic radicals such as hydroxyl, peroxyl, alkoxyl, nitrate and carbonate, but is not able to pass organelle membranes. None of the AgNPs induced any significant ROS increase after 24 h, at doses up to 20 ugmL.