Authors: T. Knight, S.S. Wise, M.D. Mason, J.P. Wise_Sr. and A-K. Ng
Affilation: University of Southern Maine, United States
Pages: 674 - 677
Keywords: nanotoxicology, gold nanoparticles, immunotoxicology
This study aims at developing cell-based assays to assess the potential cytotoxic and proinflammatory effects of nanomaterials, using 15 nm gold nanoparticles as a model. In a MTT cytotoxicity assay, significant cytotoxicity was found in RAW264.7 murine macrophages and Jurkat human T cells by gold nanoparticles (10μg/cm2 culture area; 24 hr treatment) but not in WHTBF-6 human lung fibroblasts and the RAJI human B cells. In a flow cytometry assay, the ability for the RAW264.7 macrophages to phagocytose fluorescent latex beads was found not significantly inhibited by a similar treatment. In an ELISA for cytokines, the same treatment resulted in an increase in TNF-α production by RAW264.7 and human peripheral blood mononuclear cells. Using an immunoblot assay, phosphorylation of MAP kinase family proteins was investigated, and this assay has yielded inconsistent results. Overall, the results demonstrate that the MTT assay, flow cytometric phagocytosis assay and ELISA for cytokines represent cell-based assays suitable for preliminary assessment of biological effects of nanomaterials. A more efficient (i.e. higher throughput) assay for MAP kinase signaling molecules should be considered. Our results also indicate that 15nm gold particles have differential cytotoxic effects on different cell types but consistent induction effect on the proinflammatory cytokine TNF-α.