Human alveolar epithelial cell responses to core-shell superparamagnetic iron oxide nanoparticles (SPIONs).

Superparamagnetic iron oxide nanoparticles (SPIONs) have been prepared and coated with positively (-NH3(+)) and negatively (-COO(-)) charged shells. These NPs, as well as their "bare" precursor, which actually contain surface hydroxyl groups, have been characterized in vitro, and their influence on a human epithelial cell line has been assessed in terms of cell metabolic activity, cellular membrane lysis, mitochondrial activity, and reactive oxygen species production. Their physicochemical characterizations and protein-nanoparticle interactions have been determined using dynamic light scattering, high-resolution transmission electron microscopy, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) spectrometry, and Coomassie Blue fast staining.

Coating carbon nanotubes with a polystyrene-based polymer protects against pulmonary toxicity.

Background: carbon nanotubes (CNT) can have adverse effects on health. Therefore, minimizing the risk associated with CNT exposure is of crucial importance. The aim of this work was to evaluate if coating multi-walled CNT (MWCNT) with polymers could modify their toxicity, thus representing a useful strategy to decrease adverse health effects of CNT.

Adverse effects of industrial multiwalled carbon nanotubes on human pulmonary cells.

The aim of this study was to evaluate adverse effects of multiwalled carbon nanotubes (MWCNT), produced for industrial purposes, on the human epithelial cell line A549. MWCNT were dispersed in dipalmitoyl lecithin (DPL), a component of pulmonary surfactant, and the effects of dispersion in DPL were compared to those in two other media: ethanol (EtOH) and phosphate-buffered saline (PBS). Effects of MWCNT were also compared to those of two asbestos fibers (chrysotile and crocidolite) and carbon black (CB) nanoparticles, not only in A549 cells but also in mesothelial cells (MeT5A human cell line), used as an asbestos-sensitive cell type.

Biological effects of particles from the paris subway system.

Particulate matter (PM) from atmospheric pollution can easily deposit in the lungs and induce recruitment of inflammatory cells, a source of inflammatory cytokines, oxidants, and matrix metalloproteases (MMPs), which are important players in lung structural homeostasis. In many large cities, the subway system is a potent source of PM emission, but little is known about the biological effects of PM from this source. We performed a comprehensive study to evaluate the biological effects of PM sampled at two sites (RER and Metro) in the Paris subway system.

Reversible redox- and zinc-dependent dimerization of the Escherichia coli fur protein.

Fur is a bacterial regulator using iron as a cofactor to bind to specific DNA sequences. This protein exists in solution as several oligomeric states, of which the dimer is generally assumed to be the biologically relevant one. We describe the equilibria that exist between dimeric Escherichia coli Fur and higher oligomers.