Metal load assessment in patient pulmonary lavages: towards a comprehensive mineralogical analysis including the nano-sized fraction

Abstract

Mineralogical analyses of clinical samples have been proved useful to identify causal relationship between exposure to airborne particles and pulmonary diseases. The most striking example is asbestosis where the assessment of asbestos bodies in patient lung samples has allowed defining values specific of pathologies. However this type of analyses only considers the micro-sized fraction of the particles, neglecting the specific impact of nano-sized particles which have been otherwise shown to be reactive and able to induce biological effects.Similarly, in nanotoxicology, the mineralogical analysis of pulmonary fluids could be used as an indicator of exposure to inhaled nanoparticles and could help investigations on the relationship between exposure to these nanoparticles and lung diseases. We designed this study first to demonstrate the technical feasibility of this approach, then to get a clear picture of the metals present, and in what form, in patient lungs and finally to determine if indeed it is worth investigating separately the micro, sub-micro and nano fractions. Broncho-alveolar lavages were recovered from 100 patients suffering from interstitial lung diseases. A protocol was specifically developed to isolate 3 fractions containing respectively microparticles, submicroparticles and nanoparticles with ions. The metal content in each fraction was qualitatively and quantitatively characterized. Results showed significant differences between the 3 fractions in terms of metal load confirming that the separate analysis of the fractions is relevant. It also means that the assessment of the micro-sized fraction alone, as commonly done in clinical practice, only gives a partial view of the mineralogical analysis.

Nano to micron-sized particle detection in patients' lungs and its pathological significance

“…This is partly explained by the technical challenges associated to these analyses 4 . To fill this gap, we specifically developed an innovative experimental protocol to isolate micron-sized particles from submicron/nano-sized particles, in order to separately analyze these fractions 5,6 . To illustrate the pathological relevance of mineralogical analyses, we investigated relationships between metal loads in patient BAL and clinical data with a particular emphasis on sarcoidosis 6 .…”

“…In this context, we performed an exploratory clinical study where we qualitatively and quantitatively assessed the metal load in 100 BAL from patients who suffered from interstitial lung diseases (ILD) and were in need of this invasive procedure for clinical purposes 6 . The aim of the present paper is to determine if correlations can be found between metal loads and clinical data, allowing getting new insights in the etiology of some respiratory diseases.…”

Deep Airway Inflammation and Respiratory Disorders in Nanocomposite Workers

“…In the context of non-invasive sampling of the deep airways [ 16 , 17 ], EBC is one of the few means of non-invasive monitoring of individuals exposed to nanoparticles, and several lung injury biomarkers have been measured successfully and non-invasively in EBC of individuals exposed to nanoparticles. EBC is composed mainly of water (99.9%) and contains only a small proportion of water-soluble and insoluble compounds, which presumably originate from the airway lining fluid in the form of aerosolized particles generated during the re-opening of distal airways [ 18 ].…”

Elemental fingerprint of human amniotic fluids and relationship with potential sources of maternal exposure

“…Particles were extracted based on a size-fractionation protocol consisting of a centrifugation on a glycerol cushion, for more details please see references [8,10]. Briefly, to extract the fraction containing the nanoparticles, samples were vortexed, 1 mL was taken and added with 0.5 mL dispersion buffer consisting of 50 mM Tris-base, 0.1% w/v sodium dodecyl sulfate, 150 mM NaCl, 0.5% w/v Na-deoxycholate, 5M urea, 2M thiourea and 0.8% v/v Triton X-100.…”

“…The assessment of the internal dose is a first step toward the characterization of persistent nanoparticles in tissues and the understanding of this potential source of adverse effects. With methodologies we specifically developed for that purpose, we have previously applied successfully this approach to the analysis of the nanoparticle burden in broncho-alveolar lavages [8][9][10].…”