Inhaled Nanoparticles Accumulate at Sites of Vascular Disease.
Level 4 - case-series / case-control
Mechanistic human experimental exposure and surgical tissue evaluation combined with animal disease models.
PubMed 28443337 · doi:10.1021/acsnano.6b08551
What was done
Healthy human volunteers inhaled 5 nm and 30 nm gold nanoparticles, followed by repeated blood and urine sampling from 15 minutes to 3 months post-exposure. In parallel, mice were exposed to pulmonary gold nanoparticles (2–200 nm) to evaluate systemic translocation and accumulation in vascular lesions of fat-fed apolipoprotein E-deficient models. Patients at risk of stroke also inhaled gold particles prior to carotid surgery, and excised carotid artery specimens were examined for nanoparticle uptake using high-resolution inductively coupled mass spectrometry and Raman microscopy.
What was found
In healthy humans, inhaled gold was detected in blood and urine within 15 minutes to 24 hours and persisted up to 3 months, with greater systemic levels observed for 5 nm compared to 30 nm particles. In mice, pulmonary translocation was markedly greater for particles under 10 nm, showing preferential accumulation in inflamed atherosclerotic lesions. In patients, inhaled gold particles were directly identified within surgical carotid artery disease specimens. Specific sample sizes, particle concentrations, and exact quantitative tissue measurements were not reported in the abstract.
Why it matters
This study demonstrates a direct pathway by which inhaled fine nanoparticles can cross the pulmonary barrier, enter systemic circulation, and selectively deposit at sites of vascular inflammation, providing a physical mechanism linking particulate exposure to cardiovascular pathology.
Limits
The abstract omits exact human and animal sample sizes, particle exposure doses, and detailed quantitative clearance rates. Inert gold nanoparticles serve as a tracer model and may not capture the chemical reactivity or toxicity profiles of diverse environmental air pollutants or engineered nanomaterials. Clinical endpoints such as plaque rupture or cardiovascular events were not directly evaluated.
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