Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2008-3-13
pubmed:abstractText
Ultrafine or fine titanium dioxide (TiO(2)) particles are widely used in the production of white pigments, for sunscreens, and in cleanup techniques. However, currently knowledge is deficient concerning cellular responses to these particles. The study evaluated and compared the biological activity of ultrafine and fine TiO(2) particles in RAW 264.7 macrophages according to an oxidative stress paradigm. In vitro exposure of macrophages to ultrafine or fine TiO(2) in the range of 0.5-200 microg/ml did not significantly alter cell viability. However, ultrafine TiO(2) enhanced intracellular generation of reactive oxygen species (ROS) to a greater extent than fine TiO(2) at each exposure concentration. Ultrafine TiO(2) induced ERK1/2 activation in a concentration-dependent manner, while the fine TiO(2)-induced changes were minimal. Phosphorylation of ERK1/2 occurred following 10 min exposure to higher concentrations of ultrafine TiO(2) (> or = 25 microg/ml). Similarly, ultrafine TiO(2) exposure significantly enhanced tumor necrosis factor (TNF)-alpha and macrophage inflammatory protein (MIP)-2 secretion in a concentration-dependent manner, and its potency was higher than fine TiO(2). These findings suggest that when exposure concentration is based upon equivalent mass, ultrafine TiO(2) exerts greater biological activity as measured by ROS generation, ERK 1/2 activation, and proinflammatory mediator secretion in RAW 264.7 macrophages than fine TiO(2).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1528-7394
pubmed:author
pubmed:issnType
Print
pubmed:volume
71
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
478-85
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Comparison of the biological activity between ultrafine and fine titanium dioxide particles in RAW 264.7 cells associated with oxidative stress.
pubmed:affiliation
Department of Physiology, Ewha Medical Research Center, School of Medicine, Ewha Womans University, Seoul, South Korea. jihee@ewha.ac.kr
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't