Acute and Chronic Cadmium Telluride Quantum Dots-Exposed Human Bronchial Epithelial Cells: The Effects of Particle Sizes on Their Cytotoxicity and Carcinogenicity

Biochem Biophys Res Commun. 2018 Jan 1;495(1):899-903. doi: 10.1016/j.bbrc.2017.11.074. Epub 2017 Nov 12.

Abstract

Quantum dots (QDs) are semiconducting nanocrystals with unique optical properties. When coated with shell/capping, QDs are not deleterious to cells and organisms. However, when QDs are retained in the cellular environment for a certain period of time, their coatings may be degraded, yielding "naked" QDs. Although some studies have documented the acute effects of cadmium telluride (CdTe) QDs in various cell lines, however, to our knowledge, there are no published studies on the chronic effects of CdTe QDs in normal lung cells. In this study, we therefore sought to study the effects of CdTe QDs of various particle sizes on their cytotoxicity and carcinogenicity in normal human bronchial epithelial cells (BEAS-2B). A total of three particle sizes of CdTe QD with emission maximum at 520, 580, and 730 nm were employed (abbreviated as 520Q, 580Q, and 730Q, respectively). Our results indicated that acute exposure to 520Q (∼2.04 nm in diameter) and 580Q (∼3.24 nm in diameter) elicited dose-dependent cytotoxicity; while acute exposure to 730Q (∼5.40 nm in diameter) elicited negligible cytotoxicity in BEAS-2B cells. Notably, chronic exposure to CdTe QD of all three tested particle sizes induced BEAS-2B cell transformation as evidenced by enhanced cell migration and anchorage-independent growth on soft agar. Taken together, our findings suggest that CdTe QDs are potent human lung carcinogens.

Keywords: BEAS-2B; Cadmium telluride quantum dots; Cell transformation; Cytotoxicity; Human lung cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Alveolar Epithelial Cells / drug effects*
  • Alveolar Epithelial Cells / pathology
  • Bronchial Neoplasms / chemically induced*
  • Bronchial Neoplasms / pathology
  • Cadmium Compounds / toxicity*
  • Cell Line
  • Cell Survival / drug effects
  • Cell Transformation, Neoplastic / drug effects*
  • Cell Transformation, Neoplastic / pathology
  • Chronic Disease
  • Dose-Response Relationship, Drug
  • Humans
  • Particle Size
  • Quantum Dots / toxicity*
  • Quantum Dots / ultrastructure*
  • Tellurium / toxicity*
  • Toxicity Tests

Substances

  • Cadmium Compounds
  • Tellurium
  • cadmium telluride