Response of pulmonary and cardiac cells to ceria nanoparticle exposure

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Lakshmi P. Beeravalli (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/
Advisor
Joseph Starobin

Abstract: Respiratory diseases due to penetration of ultra-fine particles are increasing at a steady rate. The main portal of entries for such particles is a gas-exchange region of the lung which has large absorption area with a thin alveolo-capillary barrier. The goal of this work is to develop this barrier and determine the toxic effects of cerium dioxide nanoparticles exposure on the developed barrier in-vitro. As a part of preliminary assessment, we aimed at investigating the in-vitro toxic effects of 15-30nm nanoceria on A549 epithelial cell line and EA.hy926 endothelial cell line monocultures. We determined cytotoxicity using membrane integrity and oxidative stress using reactive oxygen species assays. Cellular toxicity was analyzed using confocal microscopy. The A549 and EA.hy926 cell lines were cultured on either side of a permeable transwell insert to establish the co-culture and to mimic the complex 3D- structure of alveolo-capillary barrier. We found that A549 cells failed to form the tight junctions necessary for forming a functional barrier in-vitro, therefore we treated them with dexamethasone. Dexamethasone helped to form the tight junctions which was confirmed by using Confocal Microscopy and barrier electrical resistance measurements. A549 epithelial cells cultured on the apical side of the transwell insert were incubated with cerium dioxide nanoparticles for 24, 48 and 72 hours to reproduce the physiological environment with supply of nutrients from basal side and the apical pole of the cells exposed to air i.e., experiments were conducted on air liquid interface and under submerged conditions. The transport of cerium dioxide nanoparticles across the alveolo-capillary barrier was analyzed by assessing the changes in the barrier resistance measurements. We also determined the transfer of cerium dioxide nanoparticles along with the inhaled oxygen across the alveolo-capillary barrier in healthy and diseased individuals using in-silico modeling method using reaction-diffusion model. The obtained oxygen transfer values were further used to monitor the changes in the cardiac cells of healthy and diseased individuals using Fick’s law, focusing on effects in cardiac output, oxygen consumption, blood transport in arteries and veins. In summary, the experiments demonstrated that our co-culture system provides a suitable in-vitro model to examine the effects of nanoparticles on the alveolo-capillary barrier and to investigate the mechanism of particulate matter toxicity across this functional barrier.

Additional Information

Publication
Dissertation
Language: English
Date: 2020
Keywords
Air-blood barrier, Cerium dioxide nanoparticles, Fick's law, Inhalation, Pulmonary and Cardiac cells, Reaction-diffusion model
Subjects
Nanoparticles
Cerium oxides
Heart cells
Pulmonary endothelium

Email this document to