Potential for immune sensitization following dermal exposure to indium tin oxide.
Meade-BJ; Lukomska-E; Brock-K; Long-CM; Anderson-K; Anderson-S
Toxicologist 2013 Mar; 132(1):90
Pulmonary disease including pulmonary fibrosis, emphysema and pulmonary alveolar proteinosis has been observed in workers in the indium industry. The mechanisms underlying this disease and its natural history have not been fully elucidated. Among other findings, following inhalation exposure to Indium-tin Oxide (ITO) animal studies have revealed hyperplasia of mediastinal lymph nodes and granulomas of mediastinal nodes and bronchus-associated lymphoid tissue. These studies were undertaken to investigate the potential for ITO to induce immune sensitization using the mouse Local Lymph Node Assay. Furthermore studies were conducted following exposure to both intact and abraded skin to begin to evaluate the potential for dermal penetration of the nanoparticles. BALB/c mice (5 animals/per group for both intact and abraded skin groups) were exposed to either vehicle (dimethyl sulfoxide), increasing concentrations 2.5%-10% ITO (90:10 indium oxide/tin oxide, particle size <50 nm) or positive control (30% alpha-hexylcinnamaldehyde). A dose response was observed in both groups reaching statistical significance and a SI of 4 in the 5% intact dose group (EC3 value of 2.6). Students t-test showed no statistical differences when responses were compared between intact and breach skin exposures at the same dose levels. These studies demonstrate the potential for ITO to induce sensitization following dermal exposure and suggest that the particles may have similar bioavailability through intact and abraded skin.
Toxicology; Laboratory-animals; Laboratory-techniques; Exposure-assessment; Exposure-levels; Pulmonary-function; Pulmonary-system-disorders; Lung-function; Dose-response; Lung-disorders; Lung-irritants; Respiratory-system-disorders; Sensitization; Bioassays; Immune-reaction; Skin-exposure; Nanotechnology; Tin-oxides; Tissue-culture; Oxides
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The Toxicologist. Society of Toxicology 52nd Annual Meeting and ToxExpo, March 10-14, 2013, San Antonio, Texas