Article

Effects of copy center particles on the lungs: A toxicological characterization using a Balb/c mouse model

Center for Nanotechnology and Nanotoxicology, Department of Environmental Health, Harvard School of Public Health , Boston, MA , USA , and.
Inhalation Toxicology (Impact Factor: 2.34). 07/2013; 25(9). DOI: 10.3109/08958378.2013.806614
Source: PubMed

ABSTRACT Abstract Context: Printers and photocopiers release respirable particles into the air. Engineered nanomaterials (ENMs) have been recently incorporated into toner formulations but their potential toxicological effects have not been well studied. Objective: To evaluate the biological responses to copier-emitted particles in the lungs using a mouse model. Methods: Particulate matter (PM) from a university copy center was sampled and fractionated into three distinct sizes, two of which (PM0.1 and PM0.1-2.5) were evaluated in this study. The particles were extracted and dispersed in deionized water and RPMI/10% FBS. Hydrodynamic diameter and zeta potential were evaluated by dynamic light scattering. The toxicological potential of these particles was studied using 8-week-old male Balb/c mice. Mice were intratracheally instilled with 0.2, 0.6, 2.0 mg/kg bw of either the PM0.1 and PM0.1-2.5 size fractions. Fe2O3 and welding fumes were used as comparative materials, while RPMI/10% FBS was used as the vehicle control. Bronchoalveolar lavage (BAL) was performed 24 hours post-instillation. The BAL fluid was analyzed for total and differential cell counts, and biochemical markers of injury and inflammation. Results: Particle size- and dose-dependent pulmonary effects were found. Specifically, mice instilled with PM0.1 (2.0 mg/kg bw) had significant increases in neutrophil number, lactate dehydrogenase and albumin compared to vehicle control. Likewise, pro-inflammatory cytokines were elevated in mice exposed to PM0.1 (2.0 mg/kg bw) compared to other groups. Conclusion: Our results indicate that exposure to copier-emitted nanoparticles may induce lung injury and inflammation. Further exposure assessment and toxicological investigations are necessary to address this emerging environmental health pollutant.

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    • "Size-selective PM sampling was performed using the Harvard Compact Cascade Impactor (CCI), which collects particles onto impaction substrates in three stages corresponding to PM 0.1 , PM 0.1–2.5 and PM 2.5–10 size fractions (Demokritou et al., 2004). After collecting the size-fractionated PM samples, the impaction substrates were removed from the CCI and the particles were extracted using an aqueous suspension methodology (Bello et al., 2013; Chang et al., 2013; Pirela et al., 2013). "
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    • "Other recently published studies assessing the toxicological potential of ceria, titania, zinc oxide, copper oxide and iron oxide have confirmed increased inflammation, reactive oxygen species generation, neutrophilia and neurotoxicity in exposed rodents and human cell lines (Kumar & Nagesha, 2013; Landsiedel et al., 2014; Shrivastava et al., 2013). It is also worth noting that particle sizeand dose-dependent pulmonary effects were found in mice instilled with two size fractions of copier-emitted PM (PM 0.1 and PM 0.1–2.5 ) (Pirela et al., 2013). These copier emissions have a similar chemical fingerprint as those from PEPs; thus, it may be possible that this complex chemical makeup may render the PEPs deleterious to the lung to those who are exposed to them. "
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    ABSTRACT: It is well established that printers emit nanoparticles during their operation. To-date, however, the physicochemical and toxicological characterization of “real world” printer emitted nanoparticles (PEPs) remains incomplete, hampering proper risk assessment efforts. Here we investigate our earlier hypothesis that engineered nanomaterials (ENM) are used in toners and ENM are released during printing (consumer use). Furthermore, we conduct a detailed physicochemical and morphological characterization of PEPs in support of ongoing toxicological assessment work. A comprehensive suite of state of the art analytical methods and tools was employed on 11 toners from major printer manufacturers and their PEPs in a chamber design. We document a number of ENM incorporated into toner formulations (e.g., silica, alumina, titania, iron oxide, zinc oxide, copper oxide, cerium oxide, carbon black) released during printing. All evaluated toners contained large amounts of organic carbon (OC, 42-89%), metals/metal oxides (1-33%), and some elemental carbon (EC, 0.33-12%). The PEPs contained 50-90% OC, 0.001-0.5% EC and 1-3% metals. While the chemistry of the PEPs generally reflected that of their toners, considerable differences are documented. We conclude that: (i) Routine incorporation of ENM in toners classifies them as nano-enabled products (NEPs); (ii) These ENM become airborne during printing; (iii) The chemistry of PEPs is complex and it reflects that of the toner and paper. This work highlights the importance of understanding life-cycle (LC) implications of NEPs and assessing real world exposures and associated toxicological properties rather than focusing on “raw” materials used in the synthesis of an NEP.
    Nanotoxicology 10/2014; DOI:10.3109/17435390.2014.976602 · 7.34 Impact Factor
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    • "Size-selective PM sampling was performed using the Harvard Compact Cascade Impactor (CCI), which collects particles onto impaction substrates in three stages corresponding to PM 0.1 , PM 0.1–2.5 and PM 2.5–10 size fractions (Demokritou et al., 2004). After collecting the size-fractionated PM samples, the impaction substrates were removed from the CCI and the particles were extracted using an aqueous suspension methodology (Bello et al., 2013; Chang et al., 2013; Pirela et al., 2013). "
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    ABSTRACT: The printer is one of the most common office equipment. Recently, it was reported that toner formulations for printing equipment constitute nano-enabled products (NEPs) and contain engineered nanomaterials (ENMs) that become airborne during printing. To date, insufficient research has been performed to understand the potential toxicological properties of printer-emitted particles (PEPs) with several studies using bulk toner particles as test particles. These studies demonstrated the ability of toner particles to cause chronic inflammation and fibrosis in animal models. However, the toxicological implications of inhalation exposures to ENMs emitted from laser printing equipment remain largely unknown. The present study investigates the toxicological effects of PEPs using an in vitro alveolar-capillary co-culture model with Human Small Airway Epithelial Cells (SAEC) and Human Microvascular Endothelial Cells (HMVEC). Our data demonstrate that direct exposure of SAEC to low concentrations of PEPs (0.5 and 1.0 mg/mL) caused morphological changes of actin remodeling and gap formations within the endothelial monolayer. Furthermore, increased production of reactive oxygen species (ROS) and angiogenesis were observed in the HMVEC. Analysis of cytokine and chemokine levels demonstrates that interleukin (IL)-6 and MCP-1 may play a major role in the cellular communication observed between SAEC and HMVEC and the resultant responses in HMVEC. These data indicate that PEPs at low, non-cytotoxic exposure levels are bioactive and affect cellular responses in an alveolar-capillary co-culture model, which raises concerns for potential adverse health effects.
    Nanotoxicology 10/2014; DOI:10.3109/17435390.2014.976603 · 7.34 Impact Factor
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