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Harvesting Murine Alveolar Macrophages and Evaluating Cellular Activation Induced by Polyanhydride Nanoparticles
Published on: June 8, 2012
Polystyrene nanoparticle trafficking across alveolar epithelium.
Nazanin R Yacobi1, Lucas Demaio, Jiansong Xie
1Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90033, USA. nyaghoob@usc.edu
Nanomedicine : Nanotechnology, Biology, and Medicine
|April 1, 2008
Summary
Polystyrene nanoparticle (PNP) transport across lung cells depends on charge, size, and temperature. Positively charged PNPs move faster, indicating cellular energy is required for this transcellular pathway.
Area of Science:
- Nanotechnology
- Cell Biology
- Toxicology
Background:
- Nanoparticle (NP) behavior in biological systems is crucial for safety assessments.
- Understanding nanoparticle transport across lung epithelial barriers is key to predicting respiratory exposure risks.
- Polystyrene nanoparticles (PNPs) are widely used and require characterization of their biological interactions.
Purpose of the Study:
- To investigate the influence of surface charge, size, and temperature on PNP trafficking across rat alveolar epithelial cell monolayers (RAECM).
- To determine the primary pathway (transcellular vs. paracellular) for PNP translocation.
- To assess the energy dependence of PNP transport.
Main Methods:
- Exposure of RAECM to various carboxylate, sulfate, aldehyde-sulfate (negatively charged), and amidine-modified (positively charged) PNPs (20 and 100 nm).
- Measurement of apical-to-basolateral PNP fluxes as a function of PNP concentration and temperature.
- Confocal microscopy to visualize intracellular localization of PNPs.
Main Results:
- PNP trafficking rates increased with decreasing negative charge density or increasing positive charge.
- Positively charged PNPs showed 20-40 times faster trafficking than highly negatively charged PNPs.
- Trafficking rates decreased with increasing PNP diameter and were significantly lower at 4°C compared to 37°C.
- PNPs were localized within the cell cytoplasm, not in cell junctions or nuclei.
- PNP fluxes plateaued at high apical concentrations.
Conclusions:
- PNP translocation across RAECM is significantly influenced by surface charge, size, and temperature.
- PNPs primarily translocate via a transcellular route.
- PNP translocation is an active, energy-dependent process.
