Increased inflammation and altered macrophage chemotactic responses caused by two ultrafine particle types

Abstract

Background:Ultrafine particles have been hypothesised to be an important contributing factor in the toxicity and adverse health effects of particulate air pollution (PM10) and nanoparticles are used increasingly in industrial processes.Aims:To compare the ability of ultrafine and fine particles of titanium dioxide and carbon black to induce inflammation, cause epithelial injury, and affect the alveolar macrophage clearance functions of phagocytosis and chemotaxis in vivo.Methods:Rats were instilled with fine and ultrafine carbon black and titanium dioxide. Inflammation was quantified by bronchoalveolar lavage; the ability of the macrophages to phagoytose indictor fluorescent beads and to migrate towards aC5a were determined.Results:Ultrafine particles induced more PMN recruitment, epithelial damage, and cytotoxicity than their fine counterparts, exposed at equal mass. Both ultrafine and fine particles significantly impaired the phagocytic ability of alveolar macrophages. Only ultrafine particle treatment significantly enhanced the sensitivity of alveolar macrophages to chemotact towards C5a.Conclusions:Ultrafine particles of two very different materials induced inflammation and epithelial damage to a greater extent than their fine counterparts. In general, the effect of ultrafine carbon black was greater than ultrafine titanium dioxide, suggesting that there are differences in the likely harmfulness of different types of ultrafine particle. Epithelial injury and toxicity were associated with the development of inflammation after exposure to ultrafines. Increased sensitivity to a C5a chemotactic gradient could make the ultrafine exposed macrophages more likely to be retained in the lungs, so allowing dose to accumulate.

In vitro cytotoxicity and genotoxicity studies of titanium dioxide (TiO2) nanoparticles in Chinese hamster lung fibroblast cells

“…In the present study, hamster lung fibroblast cells were chosen to investigate the toxicity of TiO 2 particles because the lung is the primary target organ of TiO 2 particle toxicity (Baan et al, 2006;Rothen-Rutishauser et al, 2006), using concentrations that were relevant to those that induced toxicity in earlier in vivo studies. For example, lung epithelial injury and toxicity were identified in rats after exposure to 1000 mg/L of ultrafine TiO 2 (29 nm), and DNA damage was detected in the blood cells of the mice treated with P25 (300 mg/L) for 5 d (Renwick et al, 2004;Trouiller et al, 2009;Warheit et al, 2007). It is noteworthy that the response of rats to insoluble-particle "lung overload" is stereotyped and unique to that species.…”

“…The photocatalytic activity and cytotoxicity of the anatase nano-TiO 2 are higher than that of the rutile form (Kakinoki et al, 2004;Sayes et al, 2006). Similarly, several studies suggested that lung inflammation and consequently cancer in rats could be induced after inhalation and intratracheal instillation of TiO 2 nanoparticles, with stronger inflammogenic activity in comparison with its micron-sized counterpart (Donaldson et al, 2002;Falck et al, 2009;Renwick et al, 2004).…”

A systematic review of the physical and chemical characteristics of pollutants from biomass burning and combustion of fossil fuels and health effects in Brazil

“…It has the capacity to absorb radiation and is the principle factor in the reduction of visibility caused by air pollution 114 . Experimental and epidemiological studies show that exposure to ultrafine particles of BC are associated with increases in inflammatory cells, reduced alveolar macrophage activity and cardiovascular disease 115,116 .…”

Effect of Polycyclic Aromatic Hydrocarbons and Carbon Black Particles on Pro-Inflammatory Cytokine Secretion: Impact of PAH Coating Onto Particles

“…Indeed, ultrafine particles (aerodynamic diameter <100 nm) are responsible for a greater impact upon inflammation and macrophage function as compared to that evinced by fine particles (diameter 100 nm-2.5 µm) (Renwick et al, 2001(Renwick et al, , 2004. Thus, it is absolutely necessary to take into account the size of particles, onto which PAH are adsorbed, in order to obtain a more complete evaluation of potential immunotoxic effects.…”