Extracellular cadmium in the bronchoalveolar space of long-term tobacco smokers with and without COPD and its association with inflammation

Britt-Marie Sundblad,1,* Jie Ji,1,* Bettina Levänen,1 Klara Midander,2 Anneli Julander,2 Kjell Larsson,1 Lena Palmberg,1 Anders Lindén1 1Unit for Lung and Airway Research, 2Unit for Occupational and Environmental Dermatology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden *These authors contributed equally to this work Abstract: Tobacco contains cadmium, and this metal has been attributed a causative role in pulmonary emphysema among smokers, although extracellular cadmium has not to date been quantified in the bronchoalveolar space of tobacco smokers with or without COPD. We determined whether cadmium is enhanced in the bronchoalveolar space of long-term tobacco smokers with or without COPD in vivo, its association with inflammation, and its effect on chemokine release in macrophage-like cells in vitro. Bronchoalveolar lavage (BAL), sputum, and blood samples were collected from current, long-term smokers with and without COPD and from healthy nonsmokers. Cadmium concentrations were determined in cell-free BAL fluid using inductively coupled plasma mass spectrometry. Blood monocyte-derived macrophages were exposed to cadmium chloride in vitro. Depending upon the type of sample, molecular markers of inflammation were quantified either as protein (enzyme-linked immunosorbent assay) or as mRNA (real-time polymerase chain reaction). Cadmium concentrations were markedly increased in cell-free BAL fluid of smokers compared to that of nonsmokers (n=19–29; P<0.001), irrespective of COPD. In these smokers, the measured cadmium displayed positive correlations with macrophage TNF-α mRNA in BAL, neutrophil and CD8+ cell concentrations in blood, and finally with IL-6, IL-8, and MMP-9 protein in sputum (n=10–20; P<0.05). The cadmium chloride exposure caused a concentration-dependent increase in extracellular IL-8 protein in monocyte-derived macrophages in vitro. In conclusion, extracellular cadmium is enhanced in the bronchoalveolar space of long-term smokers and displays pro-inflammatory features. Its pathogenic role in tobacco-induced disease deserves further evaluation. Keywords: cigarette, metal, obstruction, macrophage, neutrophi

Exposure media a critical factor for controlling dissolution of CuO nanoparticles

Dissolution is an important property that influences nanoparticle abundance and biological responses, and often becomes a critical factor in determining the safety of nanoparticles. In our study, the dissolution behavior of commercial (c-CuO) and synthesized CuO (s-CuO) nanoparticles, of size 31?�?4 nm and 7?�?1 nm, respectively, in a range of simulated aqueous media (artificial sea water, artificial lysosomal fluid, simulated body fluid, and 1 mM NaNO3) was assessed. The study demonstrated significant differences in the dissolution behavior of the nanoparticles based on the exposure concentration and exposure media. In biological media, both c-CuO and s-CuO demonstrated more than 80% dissolution within 12 to 24 h as compared to less than 15% dissolution in environmental media over the 7-day period. Due to the inherent size difference between c-CuO and s-CuO nanoparticles, the rate of dissolution was found to be higher in the case of s-CuO nanoparticles. To validate the role of dissolution, the microbial response of CuO nanoparticles and its ionic species was evaluated on E. coli. This study highlights the interplay between particulate and ionic form and experimentally validates how the suspension media acts as a critical factor governing the solubility of nanoparticles.by Swaroop Chakraborty , Ashwathi Nair, ManasPaliwal, Agnieszka Dybowska and Superb K.Misr

The role of mechanically activated area on tribocorrosion of CoCrMo

Co-Cr-Mo alloys are among the most used alloys for orthopedic implants because of their excellent corrosion resistance, mechanical properties, biocompatibility. Although there is extensive literature on corrosion properties of Co-Cr-Mo alloys, fewer articles are focused on the synergistic effect of corrosion and wear in a simulated physiological solution. It is generally assumed that the current density measured during wear conditions for passive materials comes from the active area. However, there are no clear data supporting this statement. The current article correlates electrochemical measurements with the active area generated during sliding wear tests. Open circuit potential and current measurements, potentiodynamic scans, electrochemical impedance spectroscopy were carried out on samples under static and sliding wear conditions. These measurements showed the importance of the active area, where the current coming from the surface not being abraded is negligible. Finally, by combining the sliding wear and electrochemical tests, the synergistic effect of wear and corrosion was characterized for this alloy, documenting the metal carbide's detachment from the cobalt alloy matrix, which leads to a significant increase of total wear volume. © 2013 The Minerals, Metals & Materials Society and ASM International.Peer Reviewe