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Dispersion status of single walled carbon nanotubes is a key determinant of their biological activities.
Wang L; Mishra A; Castranova V; Schwegler-Berry D; Chen B; Mercer RR; Rojanasakul Y
Toxicologist 2010 Mar; 114(1):169-170
Single walled carbon nanotubes (SWCNT) have wide applications, but raise an urgent concern regarding their potential toxicities. A major obstacle to the biological and toxicological evaluation of nanoparticles is their dispersion in biological samples or buffers. SWCNT tend to form large agglomerates in solutions which affect their bioactivities. Previous studies have shown that pulmonary exposure to dispersed SWCNT, caused a greater interstitial lung fibrosis in mice than the non-dispersed form. In this study, we further investigated the effect of nanoparticle dispersion on cellular activities in vitro using a natural lung surfactant (Survanta) as a dispersing agent. Human bronchial epithelial BEAS-2B cells and human lung fibroblast CRL-1490 cells were exposed to physiologically relevant concentrations of SWCNT (0.02-0.6 ug/cm2) with or without Survanta(150ug/ml) and their effects on cell viability, proliferation, and collagen production were determined by LDH assay, cell counting, and Western blot analysis, respectively. The results showed that: 1) Survanta was effective in dispersing micron-sized SWCNT agglomerates to nano-sized structures; 2) Survanta when used alone had no significant effect on the measured cellular activities; 3) Survanta-dispersed SWCNT exhibited a biphasic effect on cells inducing proliferation at low doses and causing toxicity at high doses, while non-dispersed SWCNT had no significant effects; 4) In lung fibroblasts, dispersed SWCNT upregulated collagen expression, whereas non-dispersed SWCNT had a lesser effect. These results are supported by in vivo data and suggest that dispersed SWCNT is more fibrogenic than non-dispersed SWCNT. Due to the rapidity and simplicity of the in vitro assay models described in this study, this model could potentially be used as a rapid screening tool for fibrogenicity and toxicity testing of nanoparticles.
Biological-effects; Cell-biology; Cell-damage; Cell-function; Cellular-reactions; Exposure-assessment; Exposure-levels; Exposure-methods; Health-hazards; Inhalation-studies; Microbiology; Microscopic-analysis; Molecular-biology; Molecular-structure; Risk-analysis; Statistical-analysis; Toxic-effects; Nanotechnology
Issue of Publication
The Toxicologist. Society of Toxicology 49th Annual Meeting and ToxExpo, March 7-11, 2010, Salt Lake City, Utah