New Lymphoid Tissue Study Findings Have Been Reported by Researchers at National Institute for Public Health and the Environment (Immunotoxicity of silver nanoparticles in an intravenous 28-day repeated-dose toxicity study in rats)
By a News Reporter-Staff News Editor at Health & Medicine Week -- Researchers detail new data in Lymphoid Tissue. According to news reporting originating from Bilthoven, Netherlands, by NewsRx correspondents, research stated, "Nanosilver is used in a variety of medical and consumer products because of its antibacterial activity. This wide application results in an increased human exposure."
Our news editors obtained a quote from the research from National Institute for Public Health and the Environment, "Knowledge on the systemic toxicity of nanosilver is, however, relatively scarce. In a previous study, the systemic toxicity of 20 nm silver nanoparticles (Ag-NP) was studied in a 28-day repeated-dose toxicity study in rats. Ag-NP were intravenously administered with a maximum dose of 6 mg/kg body weight (bw)/day. Several immune parameters were affected: reduced thymus weight, increased spleen weight and spleen cell number, a strongly reduced NK cell activity, and reduced IFN-gamma production were observed. Prompted by these affected immune parameters, we wished to assess exposure effects on the functional immune system. Therefore, in the present study the T-cell dependent antibody response (TDAR) to keyhole limpet hemocyanin (KLH) was measured in a similar 28-day intravenous repeated-dose toxicity study. In addition, a range of immunological parameters was measured. Data obtained using the benchmark dose (BMD) approach were analyzed by fitting dose-response models to the parameters measured. A reduction in KLH-specific IgG was seen, with a lowest 5% lower confidence bound of the BMD (BMDL) of 0.40 mg/kg bw/day. This suggests that Ag-NP induce suppression of the functional immune system. Other parameters sensitive to Ag-NP exposure were in line with our previous study: a reduced thymus weight with a BMDL of 0.76 mg/kg bw/day, and an increased spleen weight, spleen cell number, and spleen cell subsets, with BMDLs between 0.36 and 1.11 mg/kg bw/day. Because the effects on the spleen are not reflected by increased KLH-specific IgG, they, however, do not suggest immune stimulation. Intravenous Ag-NP administration in a 28-day repeated-dose toxicity study induces suppression of the functional immune system."
According to the news editors, the research concluded: "This finding underscores the importance to study the TDAR to evaluate immunotoxicity and not to rely solely on measuring immune cell subsets."
For more information on this research see: Immunotoxicity of silver nanoparticles in an intravenous 28-day repeated-dose toxicity study in rats. Particle and Fibre Toxicology, 2014;11():1-9. Particle and Fibre Toxicology can be contacted at: Biomed Central Ltd, 236 Grays Inn Rd, Floor 6, London WC1X 8HL, England. (BioMed Central - www.biomedcentral.com/; Particle and Fibre Toxicology - www.particleandfibretoxicology.com)
The news editors report that additional information may be obtained by contacting R.J. Vandebriel, Natl Inst Public Hlth & Environm, Center Hlth Protect, NL-3720 BA Bilthoven, Netherlands. Additional authors for this research include E.C.M. Tonk, L.J. de la Fonteyne-Blankestijn, E.R. Gremmer, H.W. Verharen, L.T. van der Ven, H. van Loveren and W.H. de Jong (see also Lymphoid Tissue).
Keywords for this news article include: Europe, Spleen, Bilthoven, Nanosilver, Netherlands, Nanoparticle, Nanotechnology, Lymphoid Tissue, Emerging Technologies, Hemic and Immune Systems
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