The Toxicologist - Society of Toxicology

2051 EFFECTS OF COPPER DOPED TITANIUM DIOXIDE
NANOPARTICLES IN VIVO: ROLE OF SOLUBLE METAL.
B. L. Serke 1 , N. Corson 1 , P. Mercer 1 , R. Gelein 1 , M. Sahu 2 , P. Biswas 2 , G.
Oberdörster 1 and A. Elder 1 . 1 Environmental Medicine, University of Rochester,
Rochester, NY and 2 Energy, Environmental and Chemical Engineering, Washington
University, St. Louis, St. Louis, MO.
The production and use of nanoparticles (NPs; 90% fluorescent cells within 1 hr for both -45mV silica particles
and carboxy- quantum dots), but confocal microscopy showed that nanoparticles
were bound to the plasma membrane and not taken up by the cells. The fluorescent
and flow cytometry results were similar for differentiated THP-1 cells
(>90% fluorescent cells within 1 hr for both -45mV silica particles and carboxyquantum
dots); however, confocal microscopy demonstrated that nanoparticles
were in fact taken up by the cells. This study provides an example of a situation in
which plasma membrane binding of nanoparticles did not lead to uptake (in the
monocytes). Methods that do not effectively distinguish between plasma membrane
bound nanoparticles and particles internalized within the cell can potentially
provide misleading results regarding nanoparticle uptake. [Supported in part by the
Center for NanoBio Sensors, University of Florida]
2054 THE TOXIC EFFECTS OF MESOPOROUS SILICA
NANOPARTICLES IN MACROPHAGES.
S. Lee 1 , H. Yun 2 and S. Kim 1 . 1 Pharmacology, Kyungpook National University,
Daegu, Republic of Korea and 2 Engineering Ceramics Research Group, Functional
Materials Division, Korea Institute of Materials Science (KIMS), changwon, Republic
of Korea.
Studies on nanoparticles designed for application in biology have grown significantly
over the last few decades. However, due to their small size, many nanoparticles
can enter cell organelles and disrupt normal cell functions. Thus, there are general
concerns regarding potential toxic effects of nanoparticles after administration.
Especially, mesoporous silica (MPS) nanoparticles offer advantage in drug delivery
systems, tissue engineering, labeling and bioseparation material technologies, and
transfection devices. We investigated the toxicity of MPS and underlying mechanism
of actions in murine macrophages. MPS significantly lowered cytotoxicity for
1 or 3 days as compared with colloidal silica nanoparticles using MTT assay. We
found that apoptotic cell death was reduced on MPS treatment than colloidal silica
due to reduction of p38, c-Jun N-terminal kinase (JNK), and caspase 3 activations
on MPS. In addition, inflammatory response such as IL-1β, TNF-α, and IL-6 cytokines
were also reduced by MPS through inhibition of NF-κB in peritoneal
macrophages. These results suggested that MPS nanoparticles has lower toxicity
and inflammatory response than colloidal silica by inhibition of p38, c-Jun N-terminal
kinase (JNK), caspase 3, and NF-κB.
2055 ZNO NANOPARTICLE NEUROTOXICITY REQUIRES
CELLULAR INFLUX OF PARTICLES.
A. M. Klim 1 , B. V. Madhukar 2 and P. Cobbett 1 . 1 Pharmacology and Toxicology,
Michigan State University, East Lansing, MI and 2 Pediatrics and Human
Development, Michigan State University, East Lansing, MI.
Recent increase in the use of nanoparticles in pharmaceutical and other industries
has raised concerns of their potential impact on human health. To assess the potential
neurotoxicity of engineered ZnO nanoparticles, their effect was tested on a neuroblastoma
(N1E-115) cell line. Toxicity was evaluated using the MTT assay which
measures activity of mitochondrial reductase enzymes and is used to measure cell
viability. Initial experiments demonstrated significant cell death following cell exposure
(24 hours) to ZnO nanoparticle at concentrations greater than 100nM.
Similar loss of cell viability was produced following cell exposure to ZnO nanoparticles
at 250nM for two hours. In later experiments, it was observed that ZnO