Bioelectric and Morphological Response of Liquid-Covered Human Airway Epithelial Calu-3 Cell Monolayer to Periodic Deposition of Colloidal 3-Mercaptopropionic-Acid Coated CdSe-CdS/ZnS Core-Multishell Quantum Dots

PLoS One. 2016 Feb 25;11(2):e0149915. doi: 10.1371/journal.pone.0149915. eCollection 2016.


Lung epithelial cells are extensively exposed to nanoparticles present in the modern urban environment. Nanoparticles, including colloidal quantum dots (QDs), are also considered to be potentially useful carriers for the delivery of drugs into the body. It is therefore important to understand the ways of distribution and the effects of the various types of nanoparticles in the lung epithelium. We use a model system of liquid-covered human airway epithelial Calu-3 cell cultures to study the immediate and long-term effects of repeated deposition of colloidal 3-mercaptopropionic-acid coated CdSe-CdS/ZnS core-multishell QDs on the lung epithelial cell surface. By live confocal microscope imaging and by QD fluorescence measurements we show that the QD permeation through the mature epithelial monolayers is very limited. At the time of QD deposition, the transepithelial electrical resistance (TEER) of the epithelial monolayers transiently decreased, with the decrement being proportional to the QD dose. Repeated QD deposition, once every six days for two months, lead to accumulation of only small amounts of the QDs in the cell monolayer. However, it did not induce any noticeable changes in the long-term TEER and the molecular morphology of the cells. The colloidal 3-mercaptopropionic-acid coated CdSe-CdS/ZnS core-multishell QDs could therefore be potentially used for the delivery of drugs intended for the surface of the lung epithelia during limited treatment periods.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-Mercaptopropionic Acid / pharmacology*
  • Cadmium Compounds / chemistry
  • Cadmium Compounds / pharmacology
  • Cell Culture Techniques
  • Cell Line
  • Drug Carriers / pharmacology*
  • Electric Impedance
  • Enzyme Inhibitors / pharmacology*
  • Epithelial Cells / drug effects*
  • Humans
  • Nanoparticles
  • Quantum Dots / chemistry*
  • Respiratory Mucosa / cytology
  • Respiratory Mucosa / drug effects*
  • Selenium Compounds / chemistry
  • Selenium Compounds / pharmacology
  • Sulfides / chemistry
  • Sulfides / pharmacology
  • Zinc Compounds / chemistry
  • Zinc Compounds / pharmacology


  • Cadmium Compounds
  • Drug Carriers
  • Enzyme Inhibitors
  • Selenium Compounds
  • Sulfides
  • Zinc Compounds
  • cadmium sulfide
  • cadmium selenide
  • 3-Mercaptopropionic Acid
  • zinc sulfide

Grants and funding

The work was partially supported by Swedish Research Council (621-2011-4381). The funder provided support in the form of salaries for author Y. Fu, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of this author are articulated in the “author contributions” section.