Insights into the health effects of nanoparticles: why numbers matter
by Owen R. Moss
International Journal of Nanotechnology (IJNT), Vol. 5, No. 1, 2008

Abstract: We find that nanoparticle numbers do matter when estimating risk. Previous reports by others establish that particle surface area is related to changes in biological function of exposed cells. Many of these reports describe the impact of particle surface area on the alveolar macrophage (the primary cell involved in the clearance of particles deposited in the gas exchange region of the lung). For these cells, the change in function is indicated by a decrease in the macrophage's ability to clear particles. However, when macrophages are exposed to nanoparticles, this change in function may not be strictly due to surface chemistry: Instead, the cumulative projected area of the particles may reflect the degree to which the inner or outer surface of the macrophage is shielded from other objects or molecules. We apply this alternative interpretation to in vitro measurements of macrophage uptake of 26 nm diameter fluorescent beads and to in vivo data presented for TiO₂ nanoparticles. We show that the observed decrease in macrophage-mediated alveolar clearance of polystyrene test particles can be directly related to the potential for TiO₂ particles to mask the surface of the macrophage. We further confirm this observation by a series of confocal laser scanning microscopy in vitro studies. Both nanoparticle number and surface area are relevant; they help predict the potential for obstruction of molecular mechanisms.

Online publication date: Wed, 09-Jan-2008

The full text of this article is only available to individual subscribers or to users at subscribing institutions.

 
Existing subscribers:
Go to Inderscience Online Journals to access the Full Text of this article.

Pay per view:
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.

Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Nanotechnology (IJNT):
Login with your Inderscience username and password:

Username:        Password:          Forgotten your password?

Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.

If you still need assistance, please email subs@inderscience.com